

                                     INDEX

     Areement and Plan of Merger
     Promissory Note                    Exhibit A
     Escrow Agreement                   Exhibit B
     Employment Agreement               Exhibit C
     Employment Agreement               Exhibit D
     Noncompetition Agreement           Exhibit E
     Escrow Agreement                   Exhibit F



                          AGREEMENT AND PLAN OF MERGER

         This AGREEMENT AND PLAN OF MERGER  ("Agreement"),  dated as of February
19, 1999,  is entered into by and among BOK Financial  Corporation,  an Oklahoma
Corporation,  ("BOKF"), BOKF Merger Corporation Number Nine, a Texas corporation
and a  wholly-owned  subsidiary of BOKF  ("BOKSub"),  and Chaparral  Bancshares,
Inc., a Texas corporation ("Chaparral").

         WHEREAS,  BOKF is a  registered  bank  holding  company  under the Bank
Holding  Company  Act  of  1956,  as  amended  (the  "BHCA"),  and  BOKSub  is a
wholly-owned subsidiary of BOKF; and

         WHEREAS, Chaparral is a registered bank holding company under the BHCA,
which  controls  Canyon  Creek  National  Bank, a national  banking  association
("CCNB"); and

         WHEREAS, Chaparral owns all of the issued and outstanding capital stock
of Chaparral Bancshares of Delaware, a Delaware corporation ("Delaware"); and

         WHEREAS,  Delaware is a registered bank holding company under the BHCA,
which owns all of the issued and outstanding capital stock of CCNB; and

         WHEREAS,  the  respective  Boards  of  Directors  of each  of BOKF  and
Chaparral deem it advisable for BOKSub to merge with and into Chaparral upon the
terms and subject to the conditions described herein;

         NOW,  THEREFORE,  for and in consideration of the mutual benefits to be
derived from this Agreement and of the representations,  warranties, conditions,
and promises  hereinafter  contained,  the parties hereto  covenant and agree as
follows:


                                    ARTICLE I
                                   THE MERGER

         Section 1.1. The Merger.  Pursuant to the terms and  provisions of this
Agreement and the Texas  Business  Corporation  Act (the  "TBCA"),  BOKSub shall
merge with and into Chaparral (the "Merger").

     Section 1.2. Merging  Corporation.  BOKSub shall be the merging corporation
under the Merger and its corporate  identity and  existence,  separate and apart
from Chaparral, shall cease on consummation of the Merger.



     Section  1.3.  Surviving  Corporation.  Chaparral  shall  be the  surviving
corporation in the Merger. No changes in the articles of incorporation or bylaws
of Chaparral  shall be effected by the Merger.  The  officers  and  directors of
Chaparral  after the Merger shall be the same as the  officers and  directors of
Chaparral  as of the  Effective  Time (as  defined  in Section  9.2);  provided,
however,  Stanley A. Lybarger,  Tom E. Turner and C. Fred Ball, Jr. shall,  upon
consummation of the Merger,  be additional  members of the board of directors of
Chaparral.  It is understood that some of the current directors of Chaparral may
elect to resign on or before the Effective Time.

         Section  1.4.  Effect of the Merger.  The Merger  shall have all of the
effects provided by the TBCA. Chaparral,  as the surviving corporation,  may, at
any time after the  Effective  Time,  take any action  (including  executing and
delivering  any  documents)  in the name  and on  behalf  of  either  BOKSub  or
Chaparral  as  are  appropriate  in  order  to  carry  out  and  effectuate  the
transactions contemplated by this Agreement.

         Section 1.5.  Merger Consideration; Conversion of Shares.

         (a) At the Effective  Time,  each share common stock of Chaparral,  par
value $1.00 per share (the  "Chaparral  Common")  then  issued and  outstanding,
other than shares the holders of which have duly  exercised and perfected  their
dissenters'  rights under the TBCA,  shall be  automatically  converted into the
right  to  receive  an  amount  (the  "Merger   Consideration")   equal  to  (i)
$29,900,000,  plus (a) the  difference  (which may be a loss) between the amount
realized by CCNB  (including  principal and interest) upon collection or sale of
any of the CCFC  Assets  (as  defined  in  Section  1.7) and the Book  Value (as
defined in Section  1.7)  thereof,  between the date of this  Agreement  and the
Effective Time, minus (b) 134% of the amount of bonuses paid pursuant to Section
5.2(e) of this  Agreement,  and minus (c) the  amount of any  dividends  paid by
Chaparral to its shareholders during the period from January 1, 1999 to the date
of consummation of the Merger, divided by (ii) the number of shares of Chaparral
Common issued and  outstanding  as of the Effective  Time (and after exercise of
all of the Stock Options (as defined in Section 2.2)). The Merger  Consideration
shall be paid to each holder of the Chaparral Common as of the Effective Time as
herein provided.

         (b) Chaparral,  BOKF and BOKSub acknowledge and understand that (i) all
Stock  Options  shall be  exercised  immediately  prior to  consummation  of the
Merger,  (ii) all shares of Chaparral Common issuable upon exercise of the Stock
Options  shall  be  deemed  issued  and  outstanding  immediately  prior  to the
consummation of the Merger,  and (iii) the Chaparral Common to be converted into
the right to receive the Merger Consideration shall include, without limitation,
the Chaparral Common to be issued upon the exercise of the Stock Options.



<PAGE>


         (c) At the Effective Time, BOKF shall deposit or cause to be deposited,
each into an interest-bearing  account, (i) $400,000 of the Merger Consideration
to be governed by Section 11.2 (the "Representation  Escrow Funds"), and (ii) an
amount,  if any, equal to the aggregate Tax Basis (as defined in Section 1.7) of
the CCFC  Assets  owned  by CCNB as of the  Effective  Time  (the  "CCFC  Escrow
Funds"). The Merger  Consideration less the Representation  Escrow Funds and the
CCFC Escrow  Funds is referred to herein as the "Closing  Consideration").  Each
holder of the Chaparral Common may elect to receive the Closing Consideration in
any  combination  of (i) cash or (ii) a single  Promissory  Note  payable to the
shareholder by BOKF ("BOKF Note").  Each BOKF Note shall (i) be substantially in
the form  attached  hereto as Exhibit A (the "BOKF  Note" and  collectively  the
"BOKF Notes"); (ii) bear interest at the rate per annum equal to the "Applicable
Federal  Rate" as defined  under the Internal  Revenue Code of 1986,  as amended
(the "Code"), based upon the term of such BOKF Note, (iii) be due and payable in
full on January 2, 2000.

         (d)  Unless a  Chaparral  shareholder  (including  holders of the Stock
Options)  shall deliver to Chaparral not later than the meeting of  shareholders
of Chaparral at which the shareholders  vote on the question of approval of this
Agreement  a written  election  ("BOKF  Note  Election")  in a form  approved by
counsel to BOKF (which approval shall not be  unreasonably  withheld or delayed)
to receive the Closing Consideration or part thereof in the form of a BOKF Note,
the  shareholder  shall be  irrevocably  deemed to have  elected to receive  the
Closing  Consideration  in all cash.  Any Chaparral  shareholder  who has timely
delivered  the BOKF Note Election may withdraw  such  election,  and receive the
Closing  Consideration in all cash, by delivering written notice to Chaparral to
that effect not less than twenty (20) days prior to the Closing Date (as defined
in Section 9.2).

         (e) At the Effective  Time, all of the shares of Chaparral  Common,  by
virtue of the Merger and without any action on the part of the holders  thereof,
shall no longer be outstanding and shall be canceled and retired and shall cease
to exist, and each holder of any certificate or certificates  which  immediately
prior to the Effective Time represented  outstanding  shares of Chaparral Common
(the "Certificates") or of any holder of Stock Options shall thereafter cease to
have any rights with respect to such shares, except the right of such holders to
receive the Closing  Consideration  upon the  surrender of such  Certificate  or
Certificates or exercise of such Stock Options in accordance with Section 1.6.

         (f) At the Effective Time, each share of Chaparral Common, if any, held
in the treasury of Chaparral  immediately  prior to the Effective  Time shall be
canceled.

         (g) At the Effective Time, each share of common stock, par value $ 1.00
per share, of BOKSub  outstanding  immediately prior to the Effective Time shall
be converted into one share of Chaparral Common.

         (h) If any holder of  Chaparral  Common is entitled to dissent from the
Agreement  and the Merger under the TBCA and such holder  thereof  perfects such
holder's  rights under the TBCA in accordance with the provisions  thereof,  any
issued and outstanding shares of Chaparral Common held by such dissenting holder
("Dissenting  Shares")  shall not be  converted as described in this Section 1.5
but from and after the Effective Time shall  represent only the right to receive
such cash consideration as may be determined to be due to such dissenting holder
pursuant to the TBCA;  provided,  however,  that each share of Chaparral  Common
outstanding  immediately  prior to the  Effective  Time and held by a dissenting
holder who shall, after the Effective Time, withdraw his demand for appraisal or
lose his right of appraisal  shall have only such rights as are  provided  under
the TBCA.

         Section 1.6.  Exchange Procedures; Surrender of Certificates.



<PAGE>


         (a) The Bank of New York,  or other  entity  mutually  satisfactory  to
Chaparral  and BOKF,  shall  act as  paying  agent in the  Merger  (the  "Paying
Agent"). Immediately after the Effective Time, BOKF will cause Chaparral, as the
surviving  corporation,  to furnish the Paying Agent a corpus consisting of cash
and BOKF Notes  sufficient  in the  aggregate  for the Paying Agent to make full
payment of the Closing Consideration to the holders of all outstanding shares of
Chaparral Common (other than Dissenting Shares).

         (b) At least twenty (20) days prior to the Effective  Time,  the Paying
Agent shall mail,  without any further  action on the part of BOKF or Chaparral,
to each record holder of the Certificates, addressed to the most current address
of such  shareholders  according  to the  records  of  Chaparral,  a  letter  of
transmittal  (and  instructions)  for  use in  effecting  the  surrender  of the
Certificates  in exchange  for the Merger  Consideration.  Each such letter (the
"Merger Transmittal Letter") shall specify that delivery shall be effected,  and
risk of loss and title to the Certificates shall pass, only upon proper delivery
of the  Certificates to the Paying Agent and shall be in such form and have such
other  provisions as BOKF may reasonably  specify.  If a holder of the Chaparral
Common  surrenders  the  Certificates  representing  shares of such  stock and a
properly executed Merger  Transmittal  Letter to the Paying Agent at least three
(3)  business  days prior to the Closing  Date,  then on the Closing  Date,  the
Paying  Agent  shall pay to such  shareholder  the  Closing  Consideration  with
respect to such shares of Chaparral  Common. If a holder of the Chaparral Common
surrenders  the  Certificates  representing  shares of such stock and a properly
executed Merger  Transmittal  Letter to the Paying Agent at any time after three
(3) business  days prior to the Closing  Date,  then  promptly,  and in no event
later than three (3) business days after receipt of such Certificates and Merger
Transmittal  Letter,  the Paying Agent shall pay to such shareholder the Closing
Consideration  with respect to such shares of Chaparral  Common.  No interest on
the Closing Consideration  issuable upon the surrender of the Certificates shall
be paid or accrued  for the benefit of holders of  Certificates  (other than any
interest  on the BOKF  Notes in  accordance  with  their  terms).  If the Merger
Consideration  is to be issued to a person  other  than a person in whose name a
surrendered Certificate is registered,  it shall be a condition of issuance that
the surrendered  Certificate shall be properly endorsed or otherwise executed in
proper form for transfer and that the person  requesting such issuance shall pay
to the Paying  Agent any  required  transfer or other taxes or  establish to the
satisfaction  of the  Paying  Agent  that  such  tax  has  been  paid  or is not
applicable.

         (c) With respect to any shares of Chaparral Common that are acquired as
a result of the  exercise  of the Stock  Options,  the  purchase  price for such
shares under the Stock Options shall be subtracted  from or  "netted-out" of the
Merger  Consideration  to be paid such  shareholders  in order to provide  for a
cashless exercise of the Stock Options.  That is, upon the exercise of the Stock
Options such option  holder shall not be required to pay  Chaparral the purchase
price specified in the Stock Options, but such amount shall be deducted from the
amount of  Merger  Consideration  that  would  otherwise  have been paid to such
option holder.

         (d) After the Effective Time, there shall be no further registration or
transfers  on the records of  Chaparral  of  outstanding  certificates  formerly
representing  shares  of  Chaparral  Common  and,  if  a  certificate   formerly
representing  such  shares  is  presented  to  Chaparral  or  BOKF,  it shall be
forwarded  to the Paying  Agent for  cancellation  and  exchange  for the Merger
Consideration.



<PAGE>


         (e) All  Merger  Consideration  paid upon the  surrender  of  Chaparral
Common in accordance with the above terms and conditions shall be deemed to have
been  paid in full  satisfaction  of all  rights  pertaining  to such  shares of
Chaparral Common.

         (f) In the event any certificate  for Chaparral  Common shall have been
lost,  stolen or  destroyed,  the Paying  Agent shall issue in exchange for such
lost,  stolen or  destroyed  certificate,  such Merger  Consideration  as may be
required pursuant to this Agreement;  provided,  however,  that BOKF may, in its
discretion  and as a condition  precedent to the issuance  thereof,  require the
owner of such lost,  stolen or destroyed  certificate to deliver an affidavit of
lost certificate and indemnification  agreement in form reasonably acceptable to
BOKF.

         (g) At any time  following  six months after the Effective  Time,  BOKF
shall be entitled to terminate  the Paying Agent  relationship,  and  thereafter
holders of  Certificates  shall be  entitled  to look only to BOKF  (subject  to
abandoned  property,  escheat or other similar laws) with respect to the Closing
Consideration payable upon surrender of their Certificates.

         Section 1.7.      The CCFC Escrow and Sale of the CCFC Assets.

         (a) Schedule 1.7 sets forth, as of February 16, 1999, a list of certain
assets of CCNB (the "CCFC  Assets"),  the value of such  assets on the books and
records  of CCNB as of such date (the  "Book  Value")  and the tax basis of such
assets on the books and records of CCNB as of such date (the "Tax Basis").  From
and  after  the  date of  this  Agreement,  Chaparral  shall  cause  CCNB to use
reasonable,  good faith  efforts to collect or sell all of the CCFC Assets prior
to the  Closing  Date for  such  amounts  and at such  times  as  Chaparral  may
determine.  With the consent of BOKF,  which consent  shall not be  unreasonably
withheld,  CCNB may sell  certain  fixed  assets  currently  used by the Bank in
collecting or servicing the CCFC Assets,  or enter into contracts to lease space
or provide data processing services to the purchaser of all or substantially all
of the CCFC Assets.

         (b) If all of the CCFC Assets are not  collected  or sold by CCNB prior
to the Effective Time, prior to the Effective Time,  Chaparral shall incorporate
Canyon Creek Financial  Corporation  ("CCFC") as a Texas  corporation,  with the
shares  of  stock  of  CCFC  to be  issued  in  trust  for  the  benefit  of the
shareholders  of  Chaparral  as of the  Effective  Time  in  proportion  to such
holder's ownership of the stock of Chaparral. The persons who are members of the
Board of Directors of Chaparral  immediately prior to the Closing shall serve as
directors of CCFC.

         (c) If all of the CCFC Assets are not  collected  or sold by CCNB prior
to the Effective  Time, at the Effective  Time,  BOKF shall  establish an escrow
account  (the  "CCFC  Escrow")  with  Bank  of  Texas  Trust  Company,  National
Association (the "Escrow Agent"). The CCFC Escrow shall be governed by an escrow
agreement, the form of which is attached hereto as Exhibit "B" (the "CCFC Escrow
Agreement", which shall provide as follows:

                    (i) At the  Effective  Time,  BOKF  shall  deposit an amount
         equal to the aggregate Tax Basis of the CCFC Assets owned by CCNB as of
         the Effective Time into the CCFC Escrow (the "CCFC Escrow Funds").



<PAGE>


                  (ii) At the Effective Time, CCFC will purchase the CCFC Assets
         from CCNB and CCNB shall sell the CCFC  Assets to CCFC at such place as
         BOKF may  determine for a price equal to the aggregate Tax Basis of the
         CCFC Assets  owned by CCNB as of the  Effective  Time (the "CCFC Assets
         Purchase Price") out of the CCFC Escrow Funds. The CCFC Assets shall be
         sold  by  CCNB to CCFC  without  recourse  and in an "as is"  condition
         without any representations or warranties of any kind, other than title
         to the CCFC  Assets.  The sale and  purchase of the CCFC Assets will be
         effected  by  appropriate  documentation,  which  will be in  form  and
         substance  reasonably  acceptable  to counsel for CCFC and BOKF.  After
         consummation  of the sale and  purchase  of the CCFC  Assets  and after
         payment of the CCFC Assets  Purchase  Price to CCNB,  the Escrow Agent,
         the CCFC Escrow Agreement shall terminate.

                  (iii) BOKF  shall pay the fees and costs of the  Escrow  Agent
with respect to the CCFC Escrow.


                                   ARTICLE II
                   REPRESENTATIONS AND WARRANTIES OF CHAPARRAL

         In order to induce BOKF and BOKSub to enter into, execute,  deliver and
perform this Agreement,  Chaparral represents and warrants to BOKF and BOKSub as
follows:

         Section 2.1.  Organization, Standing and Power.

         (a) Chaparral is a corporation duly organized,  validly existing and in
good standing under laws of the State of Texas.  Chaparral (i) has all requisite
power and authority to own, lease and operate its properties and to carry on its
business as it is now being conducted; (ii) is subject to the supervision of the
Board of Governors  of the Federal  Reserve  System (the "Fed");  and (iii) is a
bank holding company registered with the Fed under the BHCA.

         (b) Delaware is a corporation  duly organized,  validly existing and in
good  standing  under  laws  of the  State  of  Delaware.  Delaware  (i) has all
requisite  power and authority to own,  lease and operate its  properties and to
carry on its  business  as it is now being  conducted;  (ii) is  subject  to the
supervision of the Fed; and (iii) is a bank holding company  registered with the
Fed under the BHCA.

         (c) CCNB is a national  banking  association  duly  organized,  validly
existing and in good standing under laws of the United States.  CCNB (i) has all
requisite  power and authority to own,  lease and operate its  properties and to
carry on its  business  as it is now being  conducted;  (ii) is  subject  to the
supervision of the Federal Deposit Insurance Corporation ("FDIC") and the Office
of the  Comptroller  of the  Currency  ("OCC");  and (iii) is an insured bank as
defined in the Federal Deposit Insurance Act.



<PAGE>


         (d)  Chaparral  has  delivered to BOKF and BOKSub  complete and correct
copies,  as of a date not more than 30 days prior to the date hereof, of (i) the
Articles of Association or Incorporation  and all amendments  thereto,  and (ii)
the Bylaws and all amendments thereto, of each of Chaparral, Delaware and CCNB.

         Section 2.2.  Capital Structure.

         (a) The  authorized  capital  stock of Chaparral  consists of 5,000,000
shares  of Common  Stock,  par value  $1.00  per share and  5,000,000  shares of
preferred  stock,  no par value  per  share.  As of the date of this  Agreement,
1,883,612  shares of Chaparral  Common were  outstanding  (net of shares held by
Chaparral  in  treasury)  and such issued and  outstanding  shares of  Chaparral
Common are held of record by the shareholders in the amounts  specified for each
such  shareholder in Schedule  2.2(a).  Chaparral does not have any  outstanding
shares of  preferred  stock nor any  commitment  or  obligation  to  repurchase,
reacquire or redeem any of the outstanding  Chaparral  Common. As of the date of
this Agreement, Chaparral had outstanding stock options granted, pursuant to the
Chaparral  Employee  Stock Option Plan and the Stock Option Plan for  Directors,
representing  the right to acquire an aggregate  of 136,128  shares of Chaparral
Common  (the  "Stock  Options").  Schedule  2.2 (b) sets  forth the name of each
person that has been  granted  Stock  Options,  the number of shares that may be
acquired as of the date of this  Agreement  by each such person and the exercise
price of such  Stock  Options.  The  Chaparral  Common  is  validly  issued  and
outstanding, fully paid and non-assessable.  Except for the Stock Options, there
are  no  outstanding  subscriptions,  conversion  privileges,  calls,  warrants,
options,  commitments  or agreements of any  character  obligating  Chaparral to
issue, sell, or dispose of any shares of any of its capital stock.

         (b) The  authorized  capital stock of Delaware  consists  solely of 300
shares of common stock, par value $1.00 per share (the "Delaware Common Stock").
As of the date of this  Agreement,  300  shares of  Delaware  Common  Stock were
issued and outstanding, and all of such outstanding shares are held of record by
Chaparral. There are no outstanding subscriptions, conversion privileges, calls,
warrants,  option, commitments or agreements obligating Delaware to issue, sell,
or dispose of any shares of any of its capital stock.

         (c) The authorized  capital stock of CCNB consists of 15,000,000 shares
of common  stock,  par value  $1.00 per share (the  "CCNB  Common  Stock"),  and
10,000,000  shares of preferred stock, par value $1.00 per share. As of the date
of this  Agreement,  1,443,600  shares of CCNB  Common  Stock  were  issued  and
outstanding,  all of  which  are  held  of  record  by  Delaware.  There  are no
outstanding  shares  of  preferred  stock,  nor  any  subscriptions,  conversion
privileges,  calls, warrants, options, commitments or agreements obligating CCNB
to issue, sell, or dispose of any shares of any of its capital stock.



<PAGE>


         Section 2.3.  Authority.  Subject to the approval of this  Agreement by
the  shareholders  of  Chaparral  as  contemplated  by Section 5.6  hereof,  the
execution  and delivery of this  Agreement  and the  consummation  of the Merger
contemplated  hereby  have been duly and  validly  authorized  by all  necessary
corporate action on the part of Chaparral. Neither the execution and delivery of
this  Agreement  nor the  consummation  of the  Merger  contemplated  hereby nor
compliance by Chaparral with any of the provisions hereof will (i) conflict with
or result in a breach of any material provision of its Articles of Incorporation
or Bylaws or  constitute  a default  (or give rise to any right of  termination,
cancellation or acceleration)  under any of the terms,  conditions or provisions
of any material note, bond,  mortgage,  indenture,  license,  agreement or other
instrument or obligation to which Chaparral is a party, or by which it or any of
its  properties  or assets  may be bound,  except for such  conflict,  breach or
default  as to which  requisite  waivers  or  consents  either  shall  have been
obtained by Chaparral by the Effective Time or the obtaining of which shall have
been waived by BOKF,  or (ii)  violate any  material  order,  writ,  injunction,
decree,  statute,  rule or  regulation  applicable  to  Chaparral  or any of its
properties  or  assets.  No  other  consent  or  approval  by  any  governmental
authority,  other than compliance with applicable  federal and state  securities
and banking laws and  regulations of the Fed, is required in connection with the
execution  and delivery by Chaparral of this  Agreement or the  consummation  by
Chaparral of the Merger contemplated hereby.

         Section 2.4.  Financial Statements.

         (a)  Chaparral  has  previously  delivered  or made  available  to BOKF
complete  copies of the (i) audited  consolidated  balance  sheets of Chaparral,
Delaware  and CCNB as of  December  31,  1997 and  related  consolidated  income
statements and statement of changes in shareholders'  equity,  together with the
notes thereto; (ii) unaudited consolidated balance sheet of Chaparral,  Delaware
and CCNB as of December 31, 1998 and the related unaudited  consolidated  income
statement for the twelve  months then ended;  and (iii) the Reports of Condition
and  Income  of CCNB as filed  with the OCC for  each of the  quarterly  periods
during 1998 (collectively the "Financial Statements").

         (b) The  information  set forth in the  Financial  Statements  presents
fairly the financial  position of  Chaparral,  Delaware and CCNB as of the dates
thereof and the results of their  operations and the changes in their  financial
position  for the  periods  indicated  in  conformity  with  generally  accepted
accounting  principles  applied  on  a  consistent  basis,  except  the  interim
statements are subject to normal year-end adjustments. Such Financial Statements
do not, as of the dates  thereof,  include any material  assets or omit to state
any  material  liabilities,  absolute  or  contingent,  or include or omit other
facts, the inclusion or omission of which renders such Financial Statements,  in
light of the  circumstances  under  which  they  were  made,  misleading  in any
material  respect;  provided,  however,  the interim  statements  are subject to
normal year-end adjustments.



<PAGE>


         Section 2.5. Absence of Changes. Since December 31, 1998, there has not
been any material  adverse  change in the condition  (financial or otherwise) of
the assets,  liabilities,  earnings or business of Chaparral,  Delaware or CCNB.
Since such date, the business of Chaparral, Delaware and CCNB has been conducted
only in the ordinary  course  consistent  with prior practices and such entities
have not incurred any additional material  liabilities (not already reflected in
the Financial  Statements)  except: (i) those incurred in the ordinary course of
business   consistent  with  past  practices   without   negligence  or  willful
malfeasance,  or (ii) expenses or liabilities  incurred in connection  with this
Agreement  and  the  transactions  contemplated  hereby.  Without  limiting  the
generality of the  foregoing,  since  December 31, 1998,  except as permitted by
this Agreement,  none of Chaparral,  Delaware,  or CCNB have paid any dividends,
made any  distributions of assets,  made any material changes in compensation or
benefits  of any  employee  (other  than by reason  of  promotion  to  increased
responsibility),  or entered into any contracts for services or materials except
such contracts and materials which either: (i) may be terminated without penalty
within 90 days or, (ii)  provide for the  payment or other  consideration  to be
furnished by Chaparral,  Delaware or CCNB in an amount of not more than $25,000,
individually  or $100,000 for all such contracts and materials.  Notwithstanding
the  foregoing,  any  changes in banking  laws,  generally  accepted  accounting
principles,  prevailing  interest rates or other  developments  which affect the
entire banking industry generally shall not be deemed to have a material adverse
effect in the financial condition,  the results of operations or the business of
Chaparral, Delaware or CCNB.

         Section 2.6.  Tax Matters.

         (a) Chaparral,  Delaware and CCNB have timely filed all federal,  state
and local (and, if applicable,  foreign) income,  franchise,  bank, excise, real
property, personal property and other tax returns required by applicable laws to
be filed by them (including,  without limitation,  estimated tax returns, income
tax returns, information returns and withholding and employment tax returns) and
have paid,  or where  payment is not required to have been made,  have set up an
adequate  reserve or accrual for the  payment of, all taxes  required to be paid
with respect of the periods  covered by such  returns  and, as of the  Effective
Time,  will have paid, or where payment is not required to have been made,  will
have set up an adequate reserve or accrual for the payment of, all taxes for any
subsequent  periods ending on or prior to the Effective Time. None of Chaparral,
Delaware nor CCNB will have any material  liability for any such taxes in excess
of the amounts so paid or reserves or accruals so established. No payment of any
amount  to any  employee  of any of  Chaparral,  Delaware,  or CCNB is an excess
parachute payment within the meaning of Section 280G of the Code.

         (b) All federal, state and local income, franchise,  bank, excise, real
property,  personal property and other tax returns filed by Chaparral,  Delaware
and CCNB are complete and accurate in all material respects.  None of Chaparral,
Delaware  nor  CCNB is  delinquent  in the  payment  of any tax,  assessment  or
governmental charge, and none of them has requested any extension of time within
which to file any tax returns in respect of any fiscal  year or portion  thereof
which have not since been filed.  There are  currently no  agreements  in effect
with respect to Chaparral,  Delaware or CCNB to extend the period of limitations
for the  assessment or  collection of any tax. As of the date hereof,  no audit,
examination or deficiency or refund  litigation  with respect to any such return
is pending or, to Chaparral's knowledge, threatened.

         Section 2.7.  Property.  Chaparral,  Delaware and CCNB own all property
reflected on the balance sheet dated December 31, 1998 included in the Financial
Statements  (except  personal  property  sold or  otherwise  disposed  of  since
December 31, 1998, in the ordinary  course of  business),  free and clear of all
mortgages,  liens,  pledges,  charges or encumbrances of any nature  whatsoever,
except those reflected in the Financial Statements,  liens for current taxes not
yet due and payable and such encumbrances and imperfections of title, if any, as
are not substantial in character or amount or do not otherwise materially impair
business operations.



<PAGE>


         Section  2.8.   Legal   Proceedings.   There  is  no  material   legal,
administrative,  arbitration or other  proceeding or governmental  investigation
pending or, to  Chaparral's  knowledge,  threatened  which might  reasonably  be
expected to result in material money damages  payable by Chaparral,  Delaware or
CCNB in  excess of  insurance  coverage  or in a  permanent  injunction  against
Chaparral,  Delaware  or CCNB.  To  Chaparral's  knowledge,  each of  Chaparral,
Delaware  and CCNB have  complied  with,  and are not in default in any material
respect  under,  any  laws,  ordinances,  requirements,  regulations  or  orders
applicable to their business. None of Chaparral,  Delaware or CCNB is a party to
any  agreement  or  instrument  or  subject to any  charter  or other  corporate
restriction  or  any  judgment,   order,  writ,  injunction,  or  decree,  which
materially and adversely affects, or might reasonably be expected materially and
adversely to affect, the business operations,  properties,  assets or condition,
financial or otherwise, of Chaparral, Delaware or CCNB.

         Section 2.9. Brokers and Finders.  None of Chaparral,  its subsidiaries
or any of its officers, directors or employees has employed any broker or finder
or incurred any liability for any brokerage  fees,  commissions or finders' fees
in connection with the Merger contemplated herein.

         Section 2.10.  Loan  Portfolio.  Except as to any breach that would not
have a  material  adverse  effect  on the  consolidated  financial  position  of
Chaparral, Delaware and CCNB, (i) all loans and discounts shown on the Financial
Statements  at December 31, 1998 or which were  entered into after  December 31,
1998, but before the Closing Date were and will be made in all material respects
for good, valuable and adequate consideration in the ordinary course of CCNB, in
accordance in all material  respects with sound banking  practices,  and are not
subject to any material  known  defenses,  setoffs or  counterclaims,  including
without  limitation  any such as are afforded by usury or truth in lending laws,
except as may be  provided  by  bankruptcy,  insolvency  or  similar  laws or by
general principles of equity;  (ii) the notes or other evidences of indebtedness
evidencing such loans and all forms of pledges,  mortgages and other  collateral
documents  and security  agreements  are and will be, in all material  respects,
enforceable,  valid,  true and  genuine  and what they  purport to be; and (iii)
Chaparral,  Delaware  and CCNB have  complied and will prior to the Closing Date
comply with all laws and  regulations  relating to such loans,  or to the extent
there has not been such  compliance,  such failure to comply will not materially
interfere with the collection of any such loan.  Notwithstanding  the foregoing,
BOKF  acknowledges  and agrees that it has made its own  determination as to the
collectibility of the loan portfolio of Chaparral and CCNB.



<PAGE>


     Section 2.11.  Environmental.  To  Chaparral's  knowledge,  the  ownership,
location,  construction,  use and operation of all real property owned or leased
by  Chaparral  or CCNB (fixed  asset or OREO) is, and has at all times been,  in
material compliance with applicable  Environmental Law, as hereinafter  defined.
Delaware  does  not own or  lease  any  real  property  and has  not  since  its
incorporation. To Chaparral's knowledge, there are no pending or threatened, and
there  have been no  administrative,  regulatory  or  judicial  actions,  suits,
demands,  demand letters,  claims, liens, notices of noncompliance or violation,
investigations  or  proceedings  relating  in any way to any  Environmental  Law
relating  to the real  property  owned by  Chaparral  or  CCNB.  To  Chaparral's
knowledge,  (i) no real property owned by Chaparral or CCNB has at any time been
used by Chaparral or CCNB, or by any person, as a landfill or for the storage or
disposal, or as a site of spilling,  dumping,  depositing or otherwise disposing
of, any hazardous or toxic  substances or waste; and (ii) no real property owned
by Chaparral or CCNB is, or has been,  an industrial  site or landfill.  For the
purposes hereof,  "Environmental Law" means any federal, state or local statute,
law,  rule,  regulation,  ordinance,  code,  policy or rule of common law now in
effect  and  in  each  case  as  amended  and  any  judicial  or  administrative
interpretation thereof, including any judicial or administrative order, consent,
decree or judgment,  relating to the environment,  health,  safety or "hazardous
materials,"   "hazardous   wastes,"  "toxic   substances,"  "toxic  pollutants,"
"contaminants,"  or words  or  terms of  similar  import  (including  under  any
Environmental Law), including without limitation the Comprehensive Environmental
Response,  Compensation and Liability Act of 1980, as amended, 42 U.S.C. 9601 et
seq., the Hazardous Materials  Transportation Act, as amended, 49 U.S.C. 1801 et
seq., the Resource  Conservation and Recovery Act, as amended, 42 U.S.C. 6901 et
seq., the Federal Water  Pollution  Control Act, as amended,  33 U.S.C.  1251 et
seq., the Toxic  Substances  Control Act, 15 U.S.C.  2601 et seq., the Clean Air
Act, 42 U.S.C.  7401 et seq.,  the Safe  Drinking  Water Act, 42 U.S.C.  3808 et
seq.,  the Texas Solid Waste  Disposal Act,  Tex.  Health & Safety Code Ann. Ch.
361, the Texas Clean Air Act, Tex.  Health & Safety Code Ann. Ch. 382, the Texas
Water Code,  Tex.  Water Code Ann.,  and the Texas  Hazardous  Substances  Spill
Prevention and Control Act, Tex. Water Code Ann.

         Section 2.12.  Zoning and Related Laws. To Chaparral's  knowledge,  all
real property owned or leased by Chaparral or CCNB and the use thereof  complies
with all  applicable  laws,  ordinances,  regulations,  orders or  requirements,
including without limitation,  building, zoning and other laws, except as to any
violations  which  would not have a  material  adverse  affect on the  financial
condition of Chaparral or CCNB.

         Section 2.13.  Compliance with Law.  Chaparral,  Delaware and CCNB have
all licenses, franchises, permits and other governmental authorizations that are
legally  required to enable them to conduct their  respective  businesses in all
material respects and are in compliance with all applicable laws and regulations
except to the extent  that the  failure  to so comply  could not have a material
adverse effect on Chaparral, Delaware or CCNB.

         Section 2.14.  Agreements with Regulatory Agencies.  None of Chaparral,
Delaware nor CCNB is subject to any  cease-and-desist  or other order issued by,
or a party to any written agreement or memorandum of understanding  with or is a
party to any commitment  letter or similar  undertaking to, or is subject to any
order or directive,  or is a recipient of any extraordinary  supervisory  letter
from, or has adopted any board resolutions at the request of (each a "Regulatory
Agreement") any regulatory  agency that materially  restricts the conduct of its
business  or that in any manner  relates  to its  capital  adequacy,  its credit
policies, its management or its business,  nor have Chaparral,  Delaware or CCNB
been  advised  by any  regulatory  agency  that  it is  considering  issuing  or
requesting any Regulatory Agreement.



<PAGE>


         Section 2.15. Employees.  Except as set forth in Schedule 2.15 attached
hereto,  (i) none of the employees of Chaparral,  Delaware,  or CCNB is employed
under any  employment  contract  (oral or written) which will survive the Merger
and (ii) none of Chaparral, Delaware, or CCNB have any employee benefit plans.

         Section 2.16.  Contracts and  Commitments.  A list of all contracts and
commitments,  other than deposit, safe deposit,  credit and lending transactions
entered  into in the  ordinary  course of  CCNB's  banking  business,  which are
material to the  business,  operations,  or financial  condition  of  Chaparral,
Delaware, or CCNB as of this date is set forth in Schedule 2.16. For the purpose
of Schedule 2.16,  materiality  shall mean those  contracts and  commitments for
which payment or other consideration to be furnished by Chaparral,  Delaware, or
CCNB is more than $25,000.  Chaparral,  Delaware, and CCNB have performed in all
material  respects  and  are  performing  all  material  contractual  and  other
obligations required to be performed by them.


                                   ARTICLE III
                     REPRESENTATIONS AND WARRANTIES OF BOKF

         In order to  induce  Chaparral  to enter  into,  execute,  deliver  and
perform this Agreement, BOKF represents and warrants to Chaparral as follows:

         Section 3.1.  Organization,  Standing and Power.  BOKF is a corporation
duly  organized,  validly  existing  and in good  standing  under  the  State of
Oklahoma.  BOKF (i) has all requisite power and authority to execute and deliver
this Agreement and to perform its obligations  hereunder,  and to own, lease and
operate its properties and to carry on its business as now being conducted;  and
(ii) is a bank holding company registered with the Fed under the BHCA.



<PAGE>


         Section 3.2.  Authority.  The execution and delivery of this Agreement,
the  consummation  of  the  Merger  and  payment  of  the  Merger  Consideration
(including  issuance and delivery of the BOKF Notes) and the other  transactions
contemplated  hereby  have been duly and  validly  authorized  by all  necessary
corporate  action on the part of BOKF.  This Agreement has been duly executed by
BOKF and  constitutes the valid and binding  obligation of BOKF,  enforceable in
accordance  with its  terms and  conditions,  except  as  enforceability  may be
limited by bankruptcy, conservatorship,  insolvency, moratorium, reorganization,
receivership  or similar laws and  judicial  decisions  affecting  the rights of
creditors  generally and by general  principles of equity (whether  applied in a
proceeding  at law or in equity).  Neither the  execution  and  delivery of this
Agreement  nor  the  consummation  of the  Merger  and  payment  of  the  Merger
Consideration  (including issuance and delivery of the BOKF Notes) and the other
transactions  contemplated  hereby  nor  compliance  by  BOKF  with  any  of the
provisions  hereof will (i) conflict with or result in a breach of any provision
of its Articles of Incorporation or Bylaws or constitute a default (or give rise
to any right of  termination,  cancellation  or  acceleration)  under any of the
terms, conditions or provisions of any note, bond, mortgage, indenture, license,
agreement or other  instrument  or  obligation  to which BOKF is a party,  or by
which  it or any of its  properties  or  assets  may be  bound  except  for such
conflict,  breach or default as to which  requisite  waivers or consents  either
shall have been  obtained by BOKF by the  Effective  Time,  or the  obtaining of
which  shall have been waived by  Chaparral,  or (ii)  violate any order,  writ,
injunction, decree, statute, rule or regulation applicable to BOKF or any of its
properties  or assets.  No consent or  approval by any  governmental  authority,
other than compliance with applicable  federal and state  securities and banking
laws and  regulations  of the Fed, is required in connection  with the execution
and delivery by BOKF of this Agreement or the consummation by BOKF of the Merger
and payment of the Merger Consideration  (including issuance and delivery of the
BOKF Notes) and the other transactions contemplated hereby.

         Section  3.3.  Subsidiaries.   Each  of  BOKF's  subsidiaries  is  duly
organized,  validly  existing  and  in  good  standing  under  the  laws  of the
jurisdiction  of its  incorporation  and  has  the  corporate  power  to own its
respective  properties and assets,  to incur its respective  liabilities  and to
carry on its respective business as now being conducted.

         Section 3.4. Financial Information.  The consolidated balance sheets of
BOKF and its  subsidiaries  as of December  31,  1997 and  related  consolidated
statements  of income,  changes in  stockholders'  equity and cash flows for the
three years ended December 31, 1997,  together with the notes thereto,  included
in BOKF's 10-K for the year ended 1997, as currently on file with the Securities
and Exchange Commission ("SEC") and the unaudited  consolidated balance sheet of
BOKF and its  subsidiaries  as of September 30, 1998, and the related  unaudited
consolidated income statement and statements of changes in stockholders'  equity
and cash flows for the nine  months  then  ended  included  in BOKF's  Quarterly
Report on Form 10-Q for the quarter  then ended,  as  currently on file with the
SEC (together the "BOKF Financial Statements"), have been prepared in accordance
with generally  accepted  accounting  principles  applied on a consistent  basis
(except as disclosed  therein)  and fairly  present the  consolidated  financial
position and the  consolidated  results of operations,  changes in stockholders'
equity and cash flows of BOKF and its consolidated  subsidiaries as of the dates
and for the  periods  indicated  (subject,  in the  case  of  interim  financial
statements,  to normal  recurring  year-end  adjustments,  none of which will be
material).

         Section 3.5.  Absence of Changes.  Since September 30, 1998,  there has
not been any material adverse change in the financial condition,  the results of
operations or the business of BOKF and its  subsidiaries  taken as a whole,  nor
have there been any events or transactions having such a material adverse effect
which  should be disclosed in order to make the BOKF  Financial  Statements  not
misleading.   Notwithstanding  the  foregoing,  any  changes  in  banking  laws,
generally accepted  accounting  principles,  prevailing  interest rates or other
developments  which affect the entire banking  industry  generally  shall not be
deemed to be a material adverse change in the financial  condition,  the results
of operations or the business of BOKF and its subsidiaries taken as a whole.

         Section  3.6.  Litigation.  There  is no  litigation,  claim  or  other
proceeding pending or, to the knowledge of BOKF, threatened, against BOKF or any
of its subsidiaries, of which the property of BOKF or any of its subsidiaries is
or would be subject which if adversely  determined would have a material adverse
effect on the business of BOKF and its subsidiaries taken as a whole.



<PAGE>


         Section  3.7.   Reports.   Since  January  1,  1993  (in  the  case  of
subsidiaries  of BOKF, the date of  acquisition  thereof by BOKF, if later) BOKF
and each of its significant  subsidiaries  has filed all reports and statements,
together with any amendments  required to be made with respect thereto,  that it
was  required to file with (i) the SEC,  (ii) the Fed,  (iii) the OCC,  (iv) the
FDIC, (v) any applicably  state securities or banking  authorities,  (vi) NASDAQ
and (vii) any other governmental authority with jurisdiction over BOKF or any of
its significant subsidiaries. As of their respective dates, each of such reports
and  documents,  as amended,  including the financial  statements,  exhibits and
schedules thereto, complied in all material respects with the relevant statutes,
rules and regulations  enforced or promulgated by the regulatory  authority with
which they were filed,  and did not contain any untrue  statement  of a material
fact or omit to state  any  material  fact  required  to be  stated  therein  or
necessary in order to make the statements therein, in light of the circumstances
under which they were made, not misleading.

         Section 3.8. Compliance With Law. BOKF and its significant subsidiaries
have all licenses,  franchises,  permits and other  governmental  authorizations
that are legally required to enable them to conduct their respective  businesses
in all material  respects and are in  compliance  with all  applicable  laws and
regulations, except to the extent that the failure to so comply would not have a
material adverse effect on BOKF and its subsidiaries taken as a whole.

         Section  3.9.  Regulatory  Approvals.  BOKF is not aware of any  matter
(including,  but not limited to,  compliance  with capital  adequacy  guidelines
adopted  by the Fed,  the  Community  Reinvestment  Act,  and FFIEC  Interagency
guidelines  establishing  year 2000  standards) that would delay or prevent BOKF
from obtaining all requisite  regulatory  approvals  necessary to consummate the
Merger as set forth in this Agreement.

         Section  3.10.  BOKF Notes.  The BOKF Notes when  issued and  delivered
pursuant to the terms of this  Agreement,  will constitute the valid and binding
obligations  of BOKF  enforceable  in  accordance  with their  terms,  except as
enforcement may be limited by applicable bankruptcy, reorganization, insolvency,
moratorium, or similar laws affecting the enforcement of creditors' rights.

         Section  3.11  Ability  to Pay  Merger  Consideration.  BOKF  will have
available  to  it  as  of  the  Closing  Date,  as  a  result  of  dividends  or
distributions  from its  subsidiaries  or  borrowings  on its  existing  line of
credit,  sufficient cash to pay the Merger Consideration as set forth in Section
1.5 to the shareholders of Chaparral.


                                   ARTICLE IV
                    REPRESENTATIONS AND WARRANTIES OF BOKSUB

         In order to  induce  Chaparral  to enter  into,  execute,  deliver  and
perform this Agreement, BOKSub represents and warrants to Chaparral as follows:

         Section 4.1. Organization,  Standing and Power. BOKSub is a corporation
duly  organized,  validly  existing and in good  standing  under the laws of the
State of Texas, with all requisite power and authority to own, lease and operate
its properties and to carry on its business as now being conducted.


<PAGE>


         Section 4.2.  Authority.  The execution and delivery of this  Agreement
and the  consummation  of the  Merger  contemplated  hereby  have  been duly and
validly  authorized  by all  necessary  corporate  action on the part of BOKSub.
Neither the execution and delivery of this  Agreement,  the  consummation of the
Merger  contemplated  hereby  nor  the  compliance  by  BOKSub  with  any of the
provisions  hereof will (i) conflict with or result in a breach of any provision
of its Articles of Incorporation or Bylaws or constitute a default (or give rise
to any right of  termination,  cancellation  or  acceleration)  under any of the
terms, conditions or provisions of any note, bond, mortgage, indenture, license,
agreement or other  instrument or  obligation to which BOKSub is a party,  or by
which  it or any of its  properties  or  assets  may be  bound  except  for such
conflict,  breach or default as to which  requisite  waivers or consents  either
shall have been  obtained by BOKSub by the  Effective  Time, or the obtaining of
which  shall  have been  waived by BOKSub,  or (ii)  violate  any  order,  writ,
injunction,  decree,  statute, rule or regulation applicable to BOKSub or any of
its properties or assets. No consent or approval by any governmental  authority,
other than those required by applicable federal and state securities and banking
laws and  regulations is required in connection  with the execution and delivery
by BOKSub of this Agreement.


                                    ARTICLE V
                              PRE-CLOSING COVENANTS

         Section 5.1.  Access to Records and Properties of Chaparral.

         (a)  Between  the  date  of this  Agreement  and  the  Effective  Time,
Chaparral  agrees  to give  BOKF  reasonable  access  to all of its  and  CCNB's
premises, books, records (including tax returns filed and those in preparation),
financial  information  and  other  information  pertinent  to  its  operations,
including,  without limitation,  access to independent  auditors with respect to
the  preparation  of the financial  statements and tax planning of Chaparral and
CCNB; provided,  however, that any such investigation shall be conducted in such
manner as not to interfere  unreasonably  with the  operation of the business of
Chaparral or CCNB.  Chaparral will cooperate  fully in permitting BOKF to make a
full  investigation  of  the  business,  properties,   financial  condition  and
investments  of Chaparral  and CCNB,  in the  preparation  of all  applications,
reports  and  other   documents   necessary  or  advisable  for  the  successful
consummation of the Merger.



<PAGE>


         (b) BOKF will treat and hold  confidential  any information  concerning
the business and affairs of  Chaparral,  Delaware or CCNB that is not  generally
available to the public  ("Confidential  Information")  it receives  from any of
Chaparral, Delaware, CCNB, or their respective shareholders, officers, directors
or agents, in the course of its review of Chaparral, Delaware or CCNB. BOKF will
not use any of the  Confidential  Information  except  in  connection  with this
Agreement.  If this Agreement is terminated for any reason whatsoever,  BOKF and
BOKSub will promptly return to Chaparral,  Delaware or CCNB, as the case may be,
all tangible embodiments (and all copies) of the Confidential  Information which
are in its possession, and will not at any time use any Confidential Information
for any  business  purpose or disclose it to any third  party.  Any  information
provided  to BOKF by  Chaparral,  Delaware  or CCNB  shall  not be  deemed to be
Confidential  Information  if: (i) it was in BOKF's lawful  possession or within
BOKF's knowledge at the time of disclosure;  (ii) at the time of disclosure,  it
was in the public  domain;  (iii)  after  Chaparral's  disclosure,  it  becomes,
through no act or omission on BOKF's part, in the public domain;  or (iv) it was
lawfully and independently obtained by BOKF from a third party who was not under
an obligation of confidentiality.

         Section 5.2.  Operation of the Business of Chaparral.  Chaparral agrees
that from the date hereof to the Effective Time,  except as contemplated by this
Agreement  or to the extent that BOKF shall  otherwise  consent  (which  consent
shall not be unreasonably withheld),

         (a)  Chaparral  will  operate its business  substantially  as presently
operated and only in the ordinary course,  and,  consistent with such operation,
it will use its reasonable best efforts to preserve intact its present  business
organization and its  relationships  with persons having business  dealings with
it.

         (b) Chaparral  will maintain and keep its  properties in as good repair
and condition as at present,  except for  depreciation  due to ordinary wear and
tear and damage due to  casualty,  maintain  in full force and effect  insurance
comparable in amount and scope of coverage to that now  maintained,  perform all
its obligations under contracts,  leases and documents  relating to or affecting
its  assets,  properties  and  business,  and fully  comply with and perform all
material  obligations  and  duties  imposed  upon  it  by  applicable  laws  and
governmental rules, regulations and orders imposed by governmental authorities.

         (c) Except as  expressly  permitted  by  subsections  (e),  (f) and (g)
below,  Chaparral  will not,  other than in the ordinary  course of business and
consistent with  Chaparral's or CCNB's prior  practices,  (i) grant any material
salary  increase  to any  officer  or  employee  or enter  into  any new  bonus,
incentive  compensation,  deferred  compensation,  profit  sharing,  retirement,
pension,  group  insurance  or  other  benefit  plan  or any new  employment  or
consulting agreement; (ii) create or otherwise become liable with respect to any
indebtedness  for money borrowed or purchase money  indebtedness;  (iii) make or
allow any amendment of its Articles of Association, Articles of Incorporation or
Bylaws;  (iv)  issue or  contract  to issue any  shares of  Chaparral  Common or
securities  exchangeable  for or convertible  into Chaparral  Common,  except in
connection  with the exercise of the Stock  Options;  (v) purchase any shares of
Chaparral Common; (vi) enter into or assume any material contract or obligation;
(vii) incur a lien on any of its properties either real or personal; (viii) make
any  substantial  renovation of any of its properties or enter into any lease or
agreement  involving  any  substantial  obligation;  or (ix)  waive any right of
substantial value.

         (d) From January 1, 1998,  until the Closing Date,  Chaparral  will not
pay  total  dividends  exceeding  the  amount of  earnings  at  Chaparral,  on a
consolidated  basis,  during such period,  and Chaparral will not permit CCNB to
pay any dividend that would cause CCNB to no longer be "well  capitalized" under
applicable federal capital adequacy guidelines.



<PAGE>


         (e) Notwithstanding anything in this Agreement to the contrary, (i) the
Stock  Options may be exercised  and  Chaparral  may issue  Chaparral  Common in
connection therewith and otherwise perform its obligations thereunder;  (ii) the
Stock  Option  exercise  dates may be extended in the  discretion  of  Chaparral
subject to the  provisions  of this  Agreement  respecting  the exercise of such
Stock Options in connection with the consummation of the Merger;  and (iii) upon
the  exercise  of the Stock  Options,  Chaparral  may make bonus  payments in an
aggregate  amount not to exceed  $650,000 to option  holders who have  exercised
Stock Options within a period of one year prior to the Closing Date.

         (f)  Notwithstanding  anything  in  this  Agreement  to  the  contrary,
Chaparral  may pay bonuses (in addition to any bonuses paid pursuant to Sections
5.2(e) and 5.2(g)) in amounts not to exceed  $175,000 for 1998 and not to exceed
$218,750 for 1999.

         (g)  Notwithstanding  anything  in  this  Agreement  to  the  contrary,
Chaparral  may commit to pay to certain key  employees of Chaparral or CCNB (who
do not enter into employment or  noncompetition  agreements) an aggregate amount
of $32,500 in consideration of such employees entering into retention agreements
whereby such employees would continue their employment with Chaparral or CCNB at
least  through  the  earlier  of (i) June 30,  2000 or (ii) the date of the data
processing  conversion  of CCNB to the data  processing  system  used by Bank of
Texas, National Association ("BOT").

         Section 5.3.  Regulatory Approvals and Cooperation.

         (a) BOKF and BOKSub shall  promptly,  but in no event later than twenty
(20)  days  after  the  date  of  this  Agreement,  file or  cause  to be  filed
applications  to fulfill all  governmental,  regulatory  and other  requirements
(including, without limitation, obtaining the approval of the OCC, the FDIC, the
Fed,  SEC  and/or  any  other  governmental   entity  having  jurisdiction  over
Chaparral,  Delaware,  CCNB or BOKF  and pay all fees  and  expenses  associated
therewith)  required  by BOKF or BOKSub for the  completion  of the  transaction
contemplated by this Agreement;  and promptly  furnish  Chaparral with copies of
all such regulatory filings.

         (b) Chaparral  shall take all action  necessary and fully  cooperate in
good faith with BOKF and BOKSub to bring about the Merger  contemplated  by this
Agreement  as soon as  practicable.  Chaparral  will give any  notices  to third
parties,  and  Chaparral  will use its best  efforts to obtain  any third  party
consents,  that BOKF may reasonably  request in connection with the consummation
of the Merger.

         Section 5.4. Public Disclosure.  None of BOKF, BOKSub,  Chaparral,  nor
any representative of said parties,  will make any public disclosure  concerning
this Agreement or the Merger  contemplated  herein without the mutual consent of
each of the other  parties  hereto to the timing and content of the  disclosure;
provided,  however,  the parties hereto may make any disclosure (i) necessary to
maintain  compliance with applicable federal or state laws or regulations,  (ii)
required in connection  with the making of any  application  necessary to effect
the Merger, or (iii) as contemplated by Section 5.6.

     Section 5.6. Shareholder Approval.  Chaparral,  acting through its Board of
Directors, shall, in accordance with applicable law:



<PAGE>


         (a) Duly  call,  give  notice  of,  convene  and hold a meeting  of its
shareholders   on  a  date  mutually   selected  by  BOKF  and  Chaparral   (the
"Shareholders's  Meeting") for  submission of this  Agreement and the Merger for
approval of such shareholders as required by the TBCA, and

         (b) Subject to its fiduciary  duties to the  shareholders of Chaparral,
include in the Proxy  Statement  (as defined  below) the  recommendation  of its
Board of  Directors  that the  shareholders  of  Chaparral  vote in favor of the
approval and adoption of the Agreement and the Merger and

         (c) Cause  the Proxy  Statement  to be  mailed to the  shareholders  of
Chaparral as soon as  practicable,  and take such other action as is  reasonably
necessary  to  obtain  approval  of  the  Agreement  and  the  Merger  from  its
shareholders. The letter to shareholders, notice of meeting, proxy statement and
form of proxy to be distributed to  shareholders  in connection  with the Merger
and the Merger Agreement shall be in form and substance reasonably  satisfactory
to BOKF and are collectively referred to herein as the "Proxy Statement."

         Section 5.7. No Solicitation.  Prior to the Effective Time, unless this
Agreement is sooner  terminated,  Chaparral shall not directly or indirectly (i)
solicit  or  encourage  inquiries  or  proposals  with  respect to the merger of
Chaparral or the sale of any of the shares of Chaparral Common or other material
asset(s) of  Chaparral  from any party  other than BOKF,  or (ii) merge with any
party or sell any of the shares of  Chaparral  Common or  material  asset(s)  of
Chaparral to any party except as set forth in this Agreement.

         Section 5.8.  Restrictions on Indebtedness.  Chaparral agrees that from
the date hereof to the Effective Time, except as contemplated by this Agreement,
Chaparral  shall not  incur any  indebtedness  for  borrowed  money or incur any
noncurrent indebtedness for the purchase price of any fixed or capital asset, or
make any extension of credit or any loans to,  guarantee the  obligations of, or
make any  additional  investments  in, any other  person,  corporation  or joint
venture (whether an existing customer or a new customer) except:

         (a)  Extensions of credit,  loans and guarantees (i) less than $300,000
per  transaction  or (ii) less than  $100,000  with  existing  customers  having
existing  credit of  $300,000  or more  made by CCNB in the  usual and  ordinary
course of its banking  business,  consistent  with prior practices and policies,
provided,  however,  that the consent of BOKF shall be deemed to have been given
unless earlier given or denied in writing (i) with respect to any loan presented
at a regularly  scheduled  meeting of CCNB's  Executive Loan  Committee,  at the
later of 3:00 p.m. on the  business day of such  meeting or the  adjournment  of
such meeting,  provided that all  information  provided to the members of CCNB's
Executive  Loan  Committee with respect to such loan is delivered to BOKF at the
same time it is delivered to such  committee  members,  and (ii) with respect to
all other loans,  at the close of business on the next business day after BOKF's
consent is  requested  and all  information  relating to the making,  renewal or
alteration of such loan is furnished to BOKF.

         (b) Legal  investments by CCNB in the usual and ordinary  course of its
banking business consistent with prior practices and policies.



<PAGE>


         (c)  Borrowings  from the Federal Home Loan Bank,  the Federal  Reserve
Bank,  deposit  liabilities,  and  federal  funds  transactions  by  CCNB in the
ordinary course of business consistent with past practices.

         Section 5.9 Audited Financial Statements. Within five (5) business days
after  receipt  thereof from  Chaparral's  auditors,  but in no event later than
March 31, 1999,  Chaparral shall furnish BOKF with audited financial  statements
of Chaparral as of December 31, 1998.


                                   ARTICLE VI
                     CONDITIONS OF MERGER - BOKF AND BOKSUB

         The   obligations  of  BOKF  and  BOKSub  to  close  the   transactions
contemplated by this Agreement are subject to the  satisfaction of the following
conditions, unless waived by BOKF and BOKSub.

         Section 6.1.  Representations  and Warranties.  The representations and
warranties of Chaparral set forth in Article II hereof shall be true and correct
in all material  respects as of the date of this Agreement and as of the Closing
Date as though made on and as of the Closing Date, except as otherwise  provided
or  permitted by this  Agreement,  and BOKF shall have  received a  certificate,
executed by the President of Chaparral to that effect.

         Section 6.2.  Performance of Obligations of Chaparral.  Chaparral shall
have performed all  obligations  and  agreements  required to be performed by it
under this Agreement in all material respects prior to or at the Closing.

         Section 6.3. Authorization of Merger. All action necessary to authorize
the execution,  delivery and  performance of this Agreement by Chaparral and the
consummation of the  transactions  contemplated  hereby shall have been duly and
validly taken by the Board of Directors of Chaparral,  and Chaparral  shall have
full power and right to merge on the terms provided herein. All action necessary
to authorize and consummate the Merger  contemplated hereby shall have been duly
and validly taken by the  shareholders of Chaparral and holders of not more than
10% of the  Chaparral  Common  either  (i)  file  with  Chaparral  prior  to the
Shareholders'  Meeting  a notice  of their  intent to  exercise  their  right to
dissent  to the  Merger or (ii) vote  against  the  Merger at the  Shareholders'
Meeting.


                                   ARTICLE VII
                        CONDITIONS OF MERGER - CHAPARRAL

         The obligation of Chaparral to close the  transactions  contemplated by
this  Agreement  is subject to the  satisfaction  of the  following  conditions,
unless waived by Chaparral:



<PAGE>


         Section 7.1.  Representations  and Warranties.  The representations and
warranties  of BOKF and BOKSub set forth in Article  III and  Article IV hereof,
respectively,  shall be true and correct in all material respects as of the date
of this  Agreement  and as of the  Closing  Date as though made on and as of the
Closing Date, except as otherwise  provided or permitted by this Agreement,  and
Chaparral shall have received a certificate,  executed by the Presidents of BOKF
and BOKSub to that effect.

         Section 7.2.  Performance of Obligations of BOKF. BOKF and BOKSub shall
have performed all  obligations  and  agreements  required to be performed by it
under this Agreement in all material respects prior to or at the Closing.

         Section  7.3.  Authorization  of Merger by BOKF and BOKSub.  All action
necessary to authorize the execution, delivery and performance of this Agreement
by BOKF and BOKSub and the consummation of the Merger  contemplated hereby shall
have been duly and validly taken by the Boards of Directors and  shareholders of
BOKF and BOKSub,  respectively,  and BOKSub and Chaparral  shall have full power
and right to merge on the terms provided herein.

         Section 7.4. Authorization of Merger by Chaparral. All action necessary
to authorize and consummate the Merger  contemplated hereby shall have been duly
and validly taken by the  shareholders of Chaparral and holders of not more than
one third of the Chaparral  Common either (i) file with  Chaparral  prior to the
Shareholders'  Meeting  a notice  of their  intent to  exercise  their  right to
dissent  to the  Merger or (ii) vote  against  the  Merger at the  Shareholders'
Meeting.


                                  ARTICLE VIII
           CONDITIONS TO RESPECTIVE OBLIGATIONS OF BOKF AND CHAPARRAL

         The respective  obligations of BOKF and Chaparral  under this Agreement
are, at their respective options, subject to the further condition that:

         Section  8.1.  Governmental  Approvals.  The parties  hereto shall have
received  approval of the Merger and issuance of the BOKF Notes as  contemplated
by this  Agreement  from all necessary  governmental  agencies and  authorities,
including,  to the extent required,  the Fed, the OCC, the FDIC and the SEC, and
such  approvals   shall  not  have  been  contested  by  any  Federal  or  state
governmental  authority nor by any other third party by formal  proceeding,  and
none of such  approvals or consents  shall be subject to any terms or conditions
that are  unreasonable  or unduly  burdensome in the opinion of the party hereto
which is obliged to  discharge  or comply with such term or  condition,  and all
applicable regulatory waiting periods have expired. It is understood that if any
contest as aforesaid is brought by formal  proceedings,  BOKF may, but shall not
be obligated to, answer and defend such contest.

         Section  8.2.  Documents.  Each party  hereto  shall have  received all
documents  required  to be  received  from  the  other  party on or prior to the
Closing Date,  including those set forth in Section 9.3 hereof,  all in form and
substance reasonably satisfactory to the receiving party.




<PAGE>


                                   ARTICLE IX
                                     CLOSING

         Section 9.1. Closing.  The closing (the "Closing") for the consummation
of the  transactions  contemplated  by this  Agreement  shall  take place at the
offices of Jenkens & Gilchrist,  a Professional  Corporation,  1445 Ross Avenue,
Suite 3200,  Dallas,  Texas 75202 at 10:00 a.m. Central Time on the Closing Date
described in Section 9.2,  unless  another date or place is agreed to in writing
by the parties hereto.

         Section 9.2. Closing Date; Effective Time. The Closing shall take place
on a date (the "Closing Date") mutually  agreeable to BOKF and Chaparral,  which
date  shall  be  within  ten  (10)  days  after  the  receipt  of all  necessary
regulatory,  corporate and other  approvals and the  expiration of any mandatory
waiting periods, provided,  however, that the Closing Date shall not occur prior
to April 2, 1999 or later than July 2, 1999. Subject to the terms and conditions
set forth herein,  including  receipt of all  regulatory  approvals,  the Merger
shall  be  effective  upon  the  later of the  filing  of,  or the date and time
specified in, the  Certificate  of Merger  relating to the Merger and filed with
the  Secretary of State of the State of Texas (the  "Effective  Time"),  and the
parties shall use their best efforts to cause the Effective Time to occur on the
Closing Date.

         Section 9.3.  Closing Deliveries.

         (a)      At the Closing, Chaparral shall deliver to BOKF and BOKSub:

               (i)  a  certified  copy  of  the  Articles  of  Incorporation  or
          Association of Chaparral, Delaware and CCNB;

                  (ii)  a  certificate,  signed  by an  appropriate  officer  of
Chaparral,  acting  solely in his capacity as an officer of  Chaparral,  stating
that (A) each of the representations  and warranties  contained in Article II is
true and correct in all  material  respects at the time of the Closing  with the
same force and effect as if such representations and warranties had been made at
Closing,  and (B) all of the  conditions  set  forth in  Article  VII have  been
satisfied or waived as provided therein;

                  (iii) a certified copy of the resolutions of Chaparral's Board
of Directors and  shareholders,  as required for valid approval of the execution
of this Agreement and the consummation of the Merger and the other  transactions
contemplated hereby;

                  (iv) good standing and existence certificates,  dated a recent
date, duly certifying the existence and good standing of Chaparral in Texas;

                  (v) executed employment  agreements for Charles O. Rolfe, Jr.,
and John B. Whisenant,  in substantially  the form as attached hereto as Exhibit
"C" and Exhibit "D", respectively;

                  (vi) an  executed  noncompetition  agreement  for  Charles  W.
Eisemann in substantially the form as attached hereto as Exhibit "E"; and


<PAGE>


                  (vii) an opinion of the  accounting  firm of Payne,  Faulkner,
Smith & Jones,  P.C., or another accounting firm mutually agreed to by Chaparral
and BOKF, in a form reasonably  acceptable to BOKF, opining that no payment,  of
which such accounting firm has knowledge, to any employee of Chaparral, Delaware
or CCNB is an excess parachute payment within the meaning of Section 280G of the
Code.

         (b) At the Closing, BOKF shall deliver to Chaparral:

                    (i)  certified  copies of the Articles of  Incorporation  of
                         BOKF and BOKSub;

                  (ii) a certificate  signed by an  appropriate  officer of BOKF
and BOKSub stating that (A) each of the representations and warranties contained
in Article III and IV is true and correct in all  material  respects at the time
of the  Closing  with the same force and effect as if such  representations  and
warranties  have been made at Closing and (B) all of the conditions set forth in
Article VI have been satisfied;

                  (ii) a certified  copy of the  resolutions  of BOKF's Board of
Directors  authorizing  the execution of this Agreement and the  consummation of
the transactions contemplated hereby;

                  (iii) a certified copy of the resolutions of BOKSub's Board of
Directors and  shareholder,  as required for valid  approval of the execution of
this Agreement and the consummation of the transactions contemplated hereby; and

                  (iv) good standing and existence certificates,  dated a recent
date, duly certifying the existence and good standing of Chaparral in Texas;

                  (v) executed employment  agreements for Charles O. Rolfe, Jr.,
and John B. Whisenant,  in substantially  the form as attached hereto as Exhibit
"C" and Exhibit "D", respectively;

                  (vi) an  executed  noncompetition  agreement  for  Charles  W.
Eisemann in substantially the form as attached hereto as Exhibit "E"; and

                  (vii) evidence of the approval of all  regulatory  authorities
required for the consummation of the Merger and the transactions contemplated by
this Agreement.


                                    ARTICLE X
                                   TERMINATION

     Section  10.1.  Termination.  This  Agreement may be terminated at any time
prior to the Effective Time by:

          (a) The mutual consent of the  respective  Boards of Directors of BOKF
     and Chaparral;



<PAGE>


         (b) BOKF if the  conditions  set forth in Article  VI hereof  shall not
have been met;

         (c) Chaparral if the  conditions  set forth in Article VII hereof shall
not have been met;

         (d) BOKF if the  conditions  set forth in Article VIII hereof shall not
have been met through no fault of, or reason attributable to, BOKF;

         (e) Chaparral if the  conditions set forth in Article VIII hereof shall
not have been met  through no fault of, or reason  attributable  to,  Chaparral,
Delaware, or CCNB; or

         (f)  Chaparral  in the event the  Closing  has not  occurred by July 2,
1999, or such other date as the parties hereto agree in writing.

         Any party desiring to terminate  this Agreement  pursuant to any of the
foregoing provisions shall give notice of such termination to the other party in
accordance with Section 12.2 hereof.

         Section 10.2. Effect of Termination.  Without limiting any other relief
to which either party  hereto may be entitled for breach of this  Agreement,  in
the event of the termination  and abandonment of this Agreement  pursuant to the
provisions  of Section 10.1 hereof,  no party to this  Agreement  shall have any
further liability or obligation in respect of this Agreement; provided, however,
that the  confidentiality  provisions  of  Section  5.1,  above,  shall  survive
termination.  Any such  termination  that  occurs  as a result  of a breach of a
representation  or warranty made in this  Agreement  that, at the time made, was
not known to the party  making  such  representation  to be untrue,  or any such
termination  that through no fault of any of the parties to this Agreement shall
be without  liability  to any of the  parties  hereto,  but if such  termination
results from the willful misrepresentation of a party or the wilful failure of a
party to fulfill a condition to the  performance  of the obligation of the other
party to this  Agreement,  such  party  shall be  fully  liable  for any and all
damages,  costs and expenses (including reasonable attorney's fees) sustained or
incurred by the other party or parties as a result of such failure or breach.

         Section  10.3.  Waiver and  Amendment.  Any term or  provision  of this
Agreement,  except statutory  requirements and requisite approvals of regulatory
authorities,  may be waived at any time by the party  which is  entitled  to the
benefits  thereof and this Agreement may be amended or  supplemented at any time
by the mutual  agreement of BOKF,  BOKSub and Chaparral  through action taken by
their respective Boards of Directors.


                                   ARTICLE XI
                              ADDITIONAL COVENANTS



<PAGE>


         Section  11.1.  No Survival.  None of the  representations,  covenants,
warranties and agreements  contained in this Agreement shall survive the Closing
and the Effective Time except (i) in accordance with Section 11.2, and (ii) this
Agreement  shall  continue  and remain in full force and  effect  regarding  the
covenants  of BOKF that by their terms are to be performed  after the  Effective
Time  (including  without  limitation  the  provisions in Section 1.5 concerning
payment of the Merger  Consideration and Sections 11.2, 11.3, 11.4 and 11.5) for
the period of the applicable statute of limitations.

         Section 11.2.  Escrow.  At the Effective  Time, BOKF shall establish an
escrow  account  (the  "Representation  Escrow")  with  the  Escrow  Agent.  The
Representation  Escrow  shall be  governed by an escrow  agreement,  the form of
which  is  attached   hereto  as  AExhibit  "F"  (the   ARepresentation   Escrow
"Agreement"), which shall provide as follows:

         (a) At the Effective Time,  BOKF shall deposit the principal  amount of
$400,000 into the Representation  Escrow,  which, together with (i) all interest
earned thereon, but reduced by (ii) any Representation  Escrow Allowed Claim (as
hereafter defined) is referred to herein as the "Representation Escrow Funds."

         (b) The Representation  Escrow Funds shall be invested in a certificate
of deposit at CCNB  maturing on March 31, 2000, at the rate and on the terms and
conditions  generally  offered by CCNB for certificates of deposit of comparable
size and duration, and upon maturity as necessary,  in three-month  certificates
of deposit at CCNB at the rates and on terms and conditions generally offered by
CCNB for  certificates  of  comparable  size and duration at each renewal  date,
provided  that any  penalty  for early  withdrawal  of such funds will either be
waived by CCNB or borne by BOKF.

         (c)  The  representations,  warranties,  covenants  and  agreements  of
Chaparral contained in this Agreement shall survive the Closing,  and BOKF shall
be indemnified  and held harmless from any and all losses,  to be decreased at a
rate of  thirty-five  percent  (35%) to account for all federal and state taxes,
arising  from any  material  breach by  Chaparral  of any such  representations,
warranties, covenants and agreements (collectively, "Losses"), provided that (i)
written  notice of such Losses must be given to Chaparral on or before March 31,
2000,  (ii) the sole remedy  available  to BOKF for any Losses  shall be limited
solely to a claim against the  Representation  Escrow Funds, (iii) all payments,
if any,  to be made in  respect  of any  Losses  shall be made  solely  from the
Representation  Escrow  Funds,  (iv) the  Chaparral  shareholders  shall have no
obligations  or  liability  for any such  Losses  except  to the  extent  of the
Representation  Escrow  Funds,  and (v) no claim  shall  be made for any  Losses
unless and until the aggregate amount of all Losses exceeds $25,000.

         (d) In the event BOKF makes no claim for any Losses on or before  March
31, 2000, the  Representation  Escrow  Agreement  shall terminate and the Escrow
Agent shall, on or before April 15, 2000,  distribute the Representation  Escrow
Funds on a pro rata  basis to the  holders  of the  Chaparral  Common  as of the
Effective Time.



<PAGE>


         (e) In the event BOKF  makes a claim for any Losses on or before  March
31, 2000, the Escrow Agent shall (i) on or before April 15, 2000,  distribute on
a pro rata basis to the holders of the Chaparral Common as of the Effective Time
an amount equal to the Representation Escrow Funds less the amount of all Losses
claimed  by  BOKF,   and  (ii)   continue  to  hold  and  invest  the  remaining
Representation  Escrow  Funds  until  such claim is  resolved  by (i) the mutual
agreement  of a majority  of the Agents (as defined  below) and BOKF,  or (ii) a
final  adjudication  determining the merits of the BOKF claim, at which time the
Representation Escrow Agreement shall terminate,  the Escrow Agent shall pay the
claim of BOKF as  mutually  agreed or finally  adjudicated  (an  "Representation
Escrow  Allowed  Claim") and the Escrow  Agent shall  distribute  any  remaining
Representation  Escrow Funds on a pro rata basis to the holders of the Chaparral
Common as of the Effective Time.

         (f)  The  rights  of  the  holders  of  the  Chaparral  Common  in  the
Representation   Escrow  and  the  Representation  Escrow  Funds  shall  not  be
assignable or  transferable  except by operation of law or by intestacy and will
not be evidenced by any certificate or other interest.

         (g) The persons who are members of the Board of  Directors of Chaparral
immediately prior to the Closing shall collectively serve as agents, acting by a
majority vote in the same manner as a board of directors  acting under the TBCA,
for the holders of the Chaparral  Common as of the Effective Time and shall have
full  authority to act for and on behalf  thereof in the  administration  of the
provisions  of this Section (the  AAgents@).  The actions of the Agents shall be
deemed  actions  taken by them as members of the Board of Directors of Chaparral
prior to the Closing.

         (h) BOKF shall pay the fees and costs of the Escrow  Agent with respect
to the Representation Escrow.

         Section 11.3.  Indemnification; Insurance.

         (a) From and after the Effective Time, BOKF (the "Indemnifying  Party")
shall indemnify and hold harmless each present and former director,  officer and
employee  of  Chaparral  and  CCNB  determined  as of the  Effective  Time  (the
"Indemnified  Parties")  against  any costs or  expenses  (including  reasonably
attorneys'  fees),  judgments,  fines,  losses,  claims,  damages or liabilities
(collectively,  "Costs")  incurred in connection with any claim,  action,  suit,
proceeding  or  investigation,  whether  civil or  criminal,  administrative  or
investigative,  arising out of matters  existing or occurring at or prior to the
Effective Time,  whether asserted or claimed prior to, at or after the Effective
Time to the fullest extent to which such Indemnified Parties were entitled under
the  Articles  of  Incorporation,  Certificate  of  Incorporation,  Articles  of
Association and Bylaws of Chaparral, Delaware and CCNB.



<PAGE>


         (b) Any Indemnified Party wishing to claim  indemnification  under this
section,   upon  learning  of  any  such  claim,  action,  suit,  proceeding  or
investigation,  shall promptly notify the Indemnifying Party, but the failure to
so notify shall not relieve the indemnifying  Party of any liability it may have
to such  Indemnified  Party if such failure does not  materially  prejudice  the
Indemnifying Party. In the event of any such claim, action, suit,  proceeding or
investigation  (whether  arising  before or after the Effective  Time),  (i) the
Indemnifying  Party shall have the right to assume the  defense  thereof and the
Indemnifying Party shall not be liable to such Indemnified Parties for any legal
expenses of other counsel or any other  expenses  subsequently  incurred by such
Indemnified  Parties in connection with the defense thereof,  except that if the
Indemnifying  Party  elects  not to  assume  such  defense  or  counsel  for the
Indemnified  Party and the  Indemnified  Parties,  the  Indemnified  Parties may
retain counsel which is reasonably  satisfactory to the Indemnifying  Party, and
the Indemnifying Party shall pay, promptly as statements  therefor are received,
the  reasonable  fees and expenses of such counsel for the  Indemnified  Parties
(which may not exceed one firm in any jurisdiction unless the use of one counsel
for such  Indemnified  Parties  would  present  such  counsel with a conflict of
interest),  (ii) the  Indemnified  Parties will  cooperate in the defense of any
such  matter  and  (iii) the  Indemnifying  Party  shall  not be liable  for any
settlement effected without its prior written consent.

         (c) BOKF shall  maintain its existing  policy of directors and officers
liability insurance (or comparable coverage) for a period of not less than three
years after the  Effective  Time;  which  policy shall be amended,  however,  to
include the directors and officers of  Chaparral,  Delaware and CCNB,  and which
shall be a "claims made" policy providing coverage for (among other things) acts
or omissions occurring prior to the Effective Time.

         (d) In the  event  that  BOKF or any of its  respective  successors  or
assigns (i)  consolidates  with or merges into any other person and shall not be
the  continuing  or surviving  corporation  or entity of such  consolidation  or
merger or (ii) transfers all or  substantially  all of its properties and assets
to any person,  then,  and in each such case, the successors and assigns of such
entity  shall  assume  the  obligations  set  forth  in  this  Agreement,  which
obligations  are expressly  intended to be for the  irrevocable  benefit of, and
shall be enforceable by, each director and officer covered hereby.

         Section 11.4. BOT Director  Position.  As soon as practicable after the
Effective  Time,  BOKF shall  cause  (pursuant  to a voting  agreement  with its
controlling  shareholder or otherwise) the Chairman of the Board of Chaparral to
be elected as a member of the Board of Directors of BOT. BOKF shall  continue to
cause such person to be nominated  and elected as a director of BOT for a period
of two years after the  Effective  Time. If for any reason such person cannot or
will not  serve as a  director  of BOKF,  BOKF  and the  board of  directors  of
Chaparral shall mutually agree to designate  another person who was on the Board
of Directors of Chaparral  as of the  Effective  Time to fill such  position for
such period of time.

         Section 11.5.  Severance  Plan.  Prior to the Closing  Date,  CCNB will
enter into a severance  policy  providing for the payment to any employee who is
involuntarily  dismissed  within the first 180 days after the Closing  Date,  an
amount  equal to one week=s  pay for each year of service or portion  thereof by
such employee, and BOKF will honor such policy after the Closing with respect to
the employees of CCNB as of the Closing Date.

         Section 11.6. Employee Benefits. BOKF presently intends that, after the
Merger,  BOKF  and  Chaparral  will  not make  additional  contributions  to the
employee benefit plans of Chaparral. Each employee of Chaparral or any direct or
indirect subsidiary of Chaparral who remains an employee of Chaparral or BOKF or
any direct or indirect  subsidiary  of Chaparral or BOKF  immediately  after the
Effective Time (the  "Continuing  Employees") will be entitled to participate in
the employee benefit plans and programs maintained for employees of BOKF and its
affiliates,  in accordance with the respective terms of such plans and programs,
and BOKF shall take all actions necessary or appropriate to facilitate  coverage
of the  Continuing  Employees  in such  plans  and  programs  from and after the
Closing Date, subject to the following:


<PAGE>


         (a) Each  Continuing  Employee  will be  entitled  to credit  for prior
service with Chaparral for all purposes under the employee welfare benefit plans
and other  employee  benefit plans and programs  (other than those  described in
subsection  B.  below  and any  stock  option  plans)  sponsored  by BOKF or its
affiliates.  Any preexisting  condition  exclusion  applicable to such plans and
programs shall be waived with respect to any Continuing  Employee.  For purposes
of  determining  each  Continuing  Employee's  benefit for the year in which the
Merger  occurs  under  the  BOKF  vacation  program,  any  vacation  taken  by a
Continuing  Employee preceding the Closing Date for the year in which the Merger
occurs will be deducted from the total BOKF vacation  benefit  available to such
employee for such year. For purposes of determining  the number of vacation days
available  with  respect to each  Continuing  Employee for the year in which the
Merger  occurs,  that  the  number  of  vacation  days for  such  year  shall be
determined under Chaparral's vacation policies in effect as of January 1, 1999.

         (b) Each  Continuing  Employee  shall be  entitled  to credit  for past
service  with  Chaparral or any of its direct or indirect  subsidiaries  for the
purpose of satisfying any eligibility or vesting periods  applicable to the BOKF
employee  pension benefit plans that are subject to Section 401(a) and 501(a) of
the Code. Notwithstanding the foregoing, BOKF shall not grant any prior years of
service  credit to employees of Chaparral,  with respect to any defined  benefit
plans sponsored (or contributed to) by BOKF; instead, Continuing Employees shall
be treated as newly hired employees of BOKF as of the date following the Closing
Date for  purposes of  determining  eligibility,  vesting  and benefit  accruals
thereunder.


                                   ARTICLE XII
                                  MISCELLANEOUS

         Section 12.1.  Entire  Agreement.  This  Agreement  contains the entire
agreement  among BOKF,  BOKSub and  Chaparral  with  respect to the Merger,  and
supersedes  all prior  agreements  and  understandings  relating  to the subject
matter of this Agreement.

         Section 12.2.  Notices.  All notices or other  communications  that are
required or permitted  hereunder shall be in writing and shall be deemed to have
been given or made on the date of  delivery,  in the case of hand  delivery,  or
three (3) business  days after  deposit in the United  States  Registered  Mail,
postage  prepaid,  or upon receipt if transmitted  by facsimile  telecopy or any
other means, addressed (in any case) as follows:

         If to BOKF or BOKSub:

         BOK Financial Corporation
         P.O.  Box 2300
         Tulsa, OK 79192
         Attention: Mr. James A. White
         Telecopy No.:  (918) 588-6853

         and


<PAGE>


         Bank of Texas, N.A.
         5956 Sherry Lane, Suite 1800
         Dallas, Texas 75225
         Attention: Mr. C. Fred Ball, Jr., President
         Telecopy No.: (214) 521-9072

         With a Copy To:

         Frederic Dorwart, Lawyers
         Old City Hall
         124 East Fourth Street
         Tulsa, OK  74103-5010
         Attention: Frederic Dorwart, Esq.
         Telecopy No.:  (918) 583-8251

         If to Chaparral:

         Chaparral Bancshares, Inc.
         333 West Campbell Road
         Richardson, Texas 75080
         Attention:  Mr. Charles W. Eisemann
         Telecopy No.:  (972) 234-8641

         With a Copy To:

         Jenkens & Gilchrist,
         a Professional Corporation
         1445 Ross Avenue, Suite 3200
         Dallas, Texas  75202-2799
         Attention: Charles E. Greef, Esq.
                       and Brian R. Marek, Esq.
         Telecopy:  (214) 855-4300

         Section  12.3.  Counterparts.  This  Agreement  may be  executed in any
number  of  counterparts,  and  each  such  counterpart  hereof,  including  any
facsimile copy thereof,  shall be deemed to be an original  instrument,  but all
such counterparts together shall constitute but one agreement.

         Section 12.4.  Governing Law. THIS  AGREEMENT  SHALL BE GOVERNED BY AND
CONSTRUED  IN  ACCORDANCE  WITH THE LAWS OF THE STATE OF TEXAS,  WITHOUT  GIVING
EFFECT TO ANY CHOICE OR CONFLICT OF LAW  PROVISION  OR RULE THAT WOULD CAUSE THE
APPLICATION OF THE LAWS OF ANY JURISDICTION OTHER THAN THE STATE OF TEXAS.



<PAGE>


         Section  12.5.  Venue.  ALL  ACTIONS OR  PROCEEDINGS  WITH  RESPECT TO,
ARISING  DIRECTLY OR INDIRECTLY IN CONNECTION  WITH,  OUT OF, RELATED TO OR FROM
THIS AGREEMENT OR ANY OF THE OTHER DOCUMENTS SHALL BE LITIGATED IN COURTS HAVING
SITUS IN DALLAS,  DALLAS COUNTY,  TEXAS, AND EACH PARTY HERETO HEREBY SUBMITS TO
THE  JURISDICTION  OF ANY SUCH COURT IN ANY SUCH  ACTION  AND HEREBY  WAIVES ANY
RIGHTS  IT MAY HAVE TO  TRANSFER  OR  CHANGE  THE  JURISDICTION  OR VENUE OF ANY
LITIGATION BROUGHT AGAINST IT IN ACCORDANCE WITH THIS SECTION.

         Section 12.6.  Additional  Documentation.  As soon as practicable after
the Effective Time, the parties hereto shall execute and file such documents and
take such  other  actions  as may be  necessary  or  appropriate  to effect  the
transactions contemplated by this Agreement.

         Section 12.7.  Severability.  If any provision of this Agreement or the
application  thereof to any person or  circumstance  shall,  to any  extent,  be
invalid or unenforceable,  the remainder of this Agreement,  and the application
of such  provision to persons or  circumstances  other than those to which it is
held invalid and unenforceable, shall not be affected thereby and each provision
of this Agreement shall be valid and enforced to the fullest extent permitted by
law.

         Section  12.8.  Expenses.  Each party shall bear and pay for all of its
own costs and expenses incurred in connection with this Agreement or the Merger,
including respective fees and expenses of financial consultants, accountants and
counsel.

         Section 12.9.  Exhibits.  The exhibits and  schedules  attached to this
agreement,  together with all documents  incorporated by reference therein, form
an  integral  part of this  Agreement  and are  hereby  incorporated  into  this
Agreement  wherever reference is made to them to the same extent as if they were
set out in full at the point in which the reference is made.  Items disclosed on
any Exhibit or Schedule to this Agreement shall be deemed to be disclosed on all
Exhibits or  Schedules  hereto and the failure of  Chaparral to list any item on
one or more  Exhibits  or  Schedules  shall  not give rise to a claim by BOKF or
BOKSub.

         Section 12.10.  Costs of  Litigation.  In any action brought by a party
hereto to enforce the  obligations  of any other party  hereto,  the  prevailing
party shall be entitled to collect from the  opposing  party to such action such
party's reasonable  litigation costs and attorneys fees and expenses  (including
court costs,  reasonable  fees of  accountants  and experts,  and other expenses
incidental to the litigation).




<PAGE>



FINIDAL:72777.  33131-00001
         IN  WITNESS  WHEREOF,  the  parties  hereto  have  duly  executed  this
Agreement as of the date and year first above written.

BOK FINANCIAL CORPORATION

By:      /S/ James Ulrich                                                     
         James Ulrich, Senior Vice President



BOKF MERGER CORPORATION NUMBER NINE

By:      /s/ C.F. Ball                                                         
         C. Fred Ball, Jr., President


CHAPARRAL BANCSHARES, INC.


By:      /s/ Charles W. Eisemann                                             
         Charles W. Eisemann, Chairman of the Board


<PAGE>


                                                   Schedule 1.7

                                   CCFC Assets
                             as of February 16, 1999


     All loans on the books of CCNB  beginning  with the numbers  20001  through
20018,   81329   through  82352  and  118193,   818740  and  4001695,   totaling
approximately 660 loans.

Principal Balance:                  $4,793,834.07
Less unearned discount        (618,949.49)
         Book Value                 $3,965,688.58

         As of this date, the Book Value of the CCFC Assets is equivalent to the
Tax Basis of such assets.


<PAGE>


                                 Schedule 2.2(a)

                    Shareholder List - Available Upon Request


<PAGE>


                                 Schedule 2.2(b)

                 List of Stock Options - Available Upon Request


<PAGE>


                                  Schedule 2.15

                   Employment Contracts and Employee Benefits


         Employment  Contracts.  There are no existing employment contracts with
the employees of Chaparral,  Delaware,  or CCNB. CCNB will enter into employment
agreements with Charles O. Rolfe,  Jr., and John B. Whisenant,  in substantially
the form as  attached  hereto as  Exhibit  "C" and  Exhibit  "D",  respectively;
pursuant to Section 9.3 of this Agreement.

       Employee Benefits. CCNB provides the following benefits to its employees:

Major Medical, Dental and Vision Insurance
Long-Term Disability Insurance
Accidental Death & Dismemberment Insurance
Life Insurance (up to two times salary, maximum of $200,000)
Vacation Benefits
Simplified Employee Pension Plan with Salary Reduction Option
Share Option Plan


<PAGE>


                                  Schedule 2.16

                            Contracts and Commitments


         CCNB has entered into a construction  contract with Pogue, Inc. for the
construction  of CCNB's branch in McKinney,  Texas.  The balance owing under the
terms of such contract is $336,856. Draws are to be paid as work is completed.

         At the request of BOKF, CCNB is currently  negotiating an Agreement for
Information   Technology  Services  with  Electronic  Data  Systems  Corporation
("EDS"),  which  agreement is expected to be executed and delivered prior to the
Closing Date.

<PAGE>

                                   EXHIBIT "A"

                                 PROMISSORY NOTE

Amount                          Dallas, Texas                               Date
$___________                                                    __________, 1999


         FOR VALUE RECEIVED,  the  undersigned,  BOK Financial  Corporation,  an
Oklahoma   corporation   ("Maker"),   hereby   promises  to  pay  to  the  order
of___________________________  ("Holder"), at the address of Holder set forth on
the  signature  page hereof,  or at such other address given to Maker by Holder,
the principal sum of _____________________________  ($______________),  together
with interest, as hereinafter described.

         This Note has been  executed  and  delivered  in  connection  with that
certain  Agreement and Plan of Merger (the "Merger  Agreement"),  dated February
19,  1999,  by and among  Maker,  BOKF Merger  Corporation  Number Nine, a Texas
corporation, and Chaparral Bancshares, Inc., a Texas corporation, and represents
all  or a  portion  of the  Merger  Consideration  (as  defined  in  the  Merger
Agreement) due to Holder. This Note is an unsecured general obligation of Maker.

   Section 1.  Interest and Payment.

         (a)  Prior  to  the  occurrence  of a  default  (hereinafter  defined),
interest shall be payable on the outstanding principal balance of this Note at a
rate per annum  equal to ____% [the  Applicable  Federal  Rate as defined in the
Internal  Revenue Code as in effect on the Closing Date].  Interest on this Note
shall be calculated at a daily rate equal to 1/360 of the annual percentage rate
which this Note bears, subject to the provisions hereof limiting interest to the
Maximum Lawful Rate (as herein defined).

         (b) The  entire  outstanding  principal  balance  of this  Note and all
accrued but unpaid interest  thereon shall be due and payable in full on January
2, 2000.

         (c) After the  occurrence  of a  default,  for so long as such  default
remains  uncured or upon  acceleration by Holder  following a default,  past due
principal,  and past due interest,  to the extent  permitted by law,  shall bear
interest at the lesser of (i) Maximum Lawful Rate or (ii) 18%.

         (d) Maker  shall not be entitled to prepay this Note in full or in part
prior to the maturity date hereof without the prior written consent of Holder.

         Section 2.  General Provisions.

         Whenever any payment shall be due under this Note on a day which is not
a business  day,  the date on which such payment is due shall be extended to the
next  succeeding  business day, and such  extension of time shall be included in
the computation of the amount of interest then payable.



<PAGE>



                                                         4
FINIDAL:72935.1  33131-00001
         All principal, interest and other sums payable under this Note shall be
paid, not later than two o'clock p.m. (Dallas, Texas time), on the day when due,
in immediately  available funds in lawful money of the United States of America.
Any  payment  under  this Note other  than in the  required  amount and in good,
unrestricted  U.S. funds  immediately  available to the holder hereof shall not,
regardless of any receipt or credit issued  therefor,  constitute  payment until
the required amount is actually  received by the holder hereof in such funds and
shall be made and accepted  subject to the condition that any check or draft may
be handled for collection in accordance with the practice of the collection bank
or banks.

         All payments  made as  scheduled on this Note shall be applied,  to the
extent  thereof,  first to accrued but unpaid interest and the balance to unpaid
principal.

         The  occurrence  of any one of the  following  shall be a default under
this Note (a "default"):

         (a)      Maker shall fail to pay when due any principal of or interest 
                  on this Note; or

         (b) Maker (1) (i) executes an assignment  for the benefit of creditors,
or takes any  action in  furtherance  thereof;  or (ii)  admits in  writing  its
inability  to pay, or fails to pay,  its debts  generally as they become due; or
(iii) as a debtor, files a petition,  case,  proceeding or other action pursuant
to, or  voluntarily  seeks the benefit or benefits of any debtor  relief law, or
takes any action in  furtherance  thereof;  or (iv) seeks the  appointment  of a
receiver,  trustee,  custodian or liquidator of any  significant  portion of its
property;  or (v) becomes subject to any  cease-and-desist or other order issued
by, or a party to any written agreement or memorandum of understanding  with, or
is a recipient of any  extraordinary  supervisory  letter from,  any  regulatory
agency;  or (2)  suffers  the filing of a petition,  case,  proceeding  or other
action against it as a debtor under any debtor relief law or seeking appointment
of a receiver,  trustee,  custodian or liquidator of any significant  portion of
its other  property;  or (3)  conceals,  removes,  or permits to be concealed or
removed,  any part of its property,  with intent to hinder, delay or defraud its
creditors or any of them,  or makes or suffers a transfer of any of its property
that may be fraudulent  under any bankruptcy,  fraudulent  conveyance or similar
law; or makes any  transfer of its  property to or for the benefit of a creditor
at a time when other creditors similarly situated have not been paid; or

         (c)  There  shall  occur (i) a change in  control  of Maker,  Chaparral
Bancshares,  Inc.,  or  Canyon  Creek  National  Bank;  (ii)  a  sale  of all or
substantially  all of the assets of any such entity; or (iii) the liquidation or
dissolution  of any such  entity.  For the  purpose  of this  Note,  a change of
control  shall be deemed to have  occurred  when and only when those persons and
entities who are  presently in control of Maker  (within the meaning of Rule 405
of the Securities and Exchange  Commission) become no longer in control of Maker
(within the meaning of said Rule 405).

         Upon the  occurrence  of a default,  the holder  hereof  shall have the
right to declare the unpaid principal balance and accrued but unpaid interest on
this Note at once due and payable (and upon such declaration,  the same shall be
at once due and  payable),  and to  exercise  any  rights,  powers and  remedies
available to Holder under this Note, or at law or in equity.


         Neither the failure by the holder hereof to exercise,  nor delay by the
holder hereof in  exercising,  the right to accelerate the maturity of this Note
or any other  right,  power or remedy upon any default  shall be  construed as a
waiver of such  default or as a waiver of the right to exercise  any such right,
power or remedy at any time. No single or partial  exercise by the holder hereof
of any right, power or remedy shall exhaust the same or shall preclude any other
or  further  exercise  thereof,  and every  such  right,  power or remedy may be
exercised at any time and from time to time.  All rights and  remedies  provided
for in this Note are  cumulative  of each other and of any and all other  rights
and  remedies  existing at law or in equity,  and the holder  hereof  shall,  in
addition to the rights and remedies provided herein, be entitled to avail itself
of all such other rights and remedies as may now or hereafter exist at law or in
equity for the collection of the indebtedness owing hereunder, and the resort to
any right or remedy  provided for  hereunder or provided for by law or in equity
shall  not  prevent  the  concurrent  or  subsequent  employment  of  any  other
appropriate rights or remedies. Without limiting the generality of the foregoing
provisions, the acceptance by the holder hereof from time to time of any payment
under this Note  which is past due or which is less than the  payment in full of
all  amounts  due  and  payable  at the  time  of such  payment,  shall  not (i)
constitute a waiver of or impair or  extinguish  the rights of the holder hereof
to accelerate the maturity of this Note or to exercise any other right, power or
remedy at the time or at any  subsequent  time, or nullify any prior exercise of
any such right,  power or remedy, or (ii) constitute a waiver of the requirement
of punctual payment and performance, or a novation in any respect.

         If any holder of this Note retains an attorney in  connection  with any
default or at maturity or to collect, enforce or defend this Note in any lawsuit
or in any probate,  reorganization,  bankruptcy or other  proceeding,  or if any
holder of this Note sues Maker in connection  with this Note,  then Maker agrees
to pay to holder,  all costs and expenses  incurred by such prevailing  party in
any such suit or proceeding, including attorneys' fees.



<PAGE>


         It is the  intent of Holder and Maker to  conform  to and  contract  in
strict  compliance  with applicable  usury law from time to time in effect.  All
agreements  between  Holder  or any other  holder  hereof  and Maker are  hereby
limited by the provisions of this paragraph which shall override and control all
such agreements,  whether now existing or hereafter  arising and whether written
or oral. In no way, nor in any event or  contingency  (including but not limited
to prepayment,  default,  demand for payment, or acceleration of the maturity of
any  obligation),  shall the rate of interest taken,  reserved,  contracted for,
charged or received  under this Note or  otherwise,  exceed the maximum  rate of
interest  permitted by applicable law (the "Maximum Lawful Rate").  If, from any
possible  construction  of any document,  interest would otherwise be payable in
excess of the Maximum Lawful Rate, any such construction shall be subject to the
provisions of this paragraph and such document shall be  automatically  reformed
and the interest  payable shall be  automatically  reduced to the Maximum Lawful
Rate,  without the necessity of execution of any  amendment or new document.  If
the holder hereof shall ever receive anything of value which is characterized as
interest  under  applicable  law and which would apart from this provision be in
excess of the Maximum  Lawful  Rate,  an amount  equal to the amount which would
have been excessive interest shall, without penalty, be applied to the reduction
of the  principal  amount  owing on the  indebtedness  evidenced  hereby  in the
inverse order of its maturity and not to the payment of interest, or refunded to
Maker or the other payor  thereof if and to the extent  such amount  which would
have been excessive exceeds such unpaid  principal.  The right to accelerate the
maturity of this Note does not include the right to accelerate any interest that
has not  otherwise  accrued  on the date of such  acceleration,  and the  holder
hereof does not intend to charge or receive any  unearned  interest in the event
of  acceleration.  All interest  paid or agreed to be paid to the holder  hereof
shall,  to the extent  permitted  by  applicable  law, be  amortized,  prorated,
allocated and spread  throughout the full stated term  (including any renewal or
extension)  of such  indebtedness  so that the amount of  interest on account of
such  indebtedness does not exceed the maximum  nonusurious  amount permitted by
applicable law. As used in this paragraph,  the term "applicable law" shall mean
the  laws of the  State  of  Texas or the  federal  laws of the  United  States,
whichever  laws  allow the  greater  interest,  as such laws now exist or may be
changed or amended or come into effect in the future.

         Maker and all sureties,  endorsers,  guarantors and any other party now
or  hereafter  liable for the  payment of this Note in whole or in part,  hereby
severally  waive  demand,  presentment  for  payment,  notice of dishonor and of
nonpayment,  protest, notice of protest, notice of intent to accelerate,  notice
of acceleration and all other notices of any kind.

         This Note may not be changed,  amended or modified  except in a writing
expressly  intended  for such  purpose and  executed by the party  against  whom
enforcement of the change, amendment or modification is sought.

         All of the covenants, stipulations,  promises, and agreements contained
in this Note by or on behalf of Maker  shall bind its  successors  and  assigns,
whether so expressed or not.

         THIS NOTE, AND ITS VALIDITY,  ENFORCEMENT AND INTERPRETATION,  SHALL BE
GOVERNED BY TEXAS LAW (WITHOUT  REGARD TO ANY CONFLICT OF LAWS  PRINCIPLES)  AND
APPLICABLE UNITED STATES FEDERAL LAW.

         Time  shall be of the  essence  in this  Note  with  respect  to all of
Maker's obligations hereunder.

     THIS NOTE REPRESENTS THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE
CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS
OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

         IN WITNESS  WHEREOF,  Maker has duly executed this Note to be effective
as of the day and year first above written.

                                     MAKER:


ADDRESS OF HOLDER:                          BOK FINANCIAL CORPORATION,
                                            an Oklahoma corporation
-------------------------

_________________________           By: _______________________________        
                                        Name:
_________________________               Title:



<PAGE>

                                   EXHIBIT "B"

                                ESCROW AGREEMENT


         This   ESCROW   AGREEMENT   has  been   executed   this   ____  day  of
_______________, 1999, by and between BOK Financial Corporation ("BOKF"), Canyon
Creek Financial Corporation ("CCFC"), and Bank of Texas Trust Company,  National
Association (the "Escrow Agent").

         BOKF has  deposited  in escrow with the Escrow Agent an amount equal to
the  Aggregate Tax Basis of the CCFC Assets  pursuant to that certain  Agreement
and Plan of Merger  dated as of  February  19,  1999,  among  BOKF,  BOKF Merger
Corporation   Number  Nine,   and  Chaparral   Bancshares,   Inc.  (the  "Merger
Agreement").  The  parties  agree  that this  escrow  shall be  administered  in
accordance with Section 1.7 of the Merger Agreement,  a true and correct copy of
which is attached hereto and  incorporated  herein by this  reference.  BOKF and
CCFC (as defined in Section 1.7 of the Merger  Agreement)  shall jointly provide
all notices to the Escrow Agent required by Section 1.7 of the Merger  Agreement
to fulfil the terms and conditions of the Escrow  Account,  and the Escrow Agent
shall act only pursuant to the joint written instructions of BOKF and CCFC.

         The  parties  to  this  Escrow   Agreement  agree  that  the  following
provisions  shall  control  with  respect  to the  rights  duties,  liabilities,
privileges and immunities of the Escrow Agent.

         (a) The Escrow Agent is not a party to, and is not bound by, or charged
with notice of, any agreement out of which this escrow may arise.

         (b) The Escrow Agent acts  hereunder as a depository  only,  and is not
responsible or liable in any manner whatever for the  sufficiency,  correctness,
genuineness  or  validity  of the  subject  matter  of the  escrow,  or any part
thereof,  or for the form or execution thereof, or for the identity or authority
of any person  executing  or  depositing  it.  The Escrow  Agent will not render
investment advice with respect to the subject matter of this escrow.

         (c) In the event the Escrow Agent  becomes  involved in  litigation  in
connection  with this escrow,  the  undersigned  jointly and severally  agree to
indemnify  and save the Escrow  Agent  harmless  from all loss,  cost,  damages,
expenses  and  attorney's  fees  suffered or  incurred by the Escrow  Agent as a
result thereof.

         (d) The Escrow  Agent  shall be  protected  in acting  upon any written
notice, request, waiver, consent, certificate, receipt, authorization,  power of
attorney  or other  paper or  document  which  the  Escrow  Agent in good  faith
believes to be genuine and what it purports to be.

         (e) The Escrow Agent shall not be liable for anything that it may do or
refrain from doing in connection  herewith,  except its own gross  negligence or
willful misconduct.



<PAGE>


         (f) The Escrow Agent may consult with legal counsel in the event of any
dispute or question as to the  construction  of any of the provisions  hereof or
its  duties  hereunder,  and it shall  incur  no  liability  and  shall be fully
protected  in acting in  accordance  with the opinion and  instructions  of such
counsel.

         (g) In the event of any disagreement between any of the parties to this
agreement,  or  between  them or  either  of any of them and any  other  person,
resulting in adverse claims or demands being made in connection with the subject
matter of the escrow,  or in the event that the Escrow Agent,  in good faith, be
in doubt as to what action it should take  hereunder,  the Escrow  Agent may, at
its option, refuse to comply with any claims or demands on it, or refuse to take
any other action hereunder, so long as such disagreement continues or such doubt
exists, and in any such event, the Escrow Agent shall not be or become liable in
any way or to any person for its failure or refusal to act, and the Escrow Agent
shall be entitled to continue so to refrain  from acting until (i) the rights of
all  parties  shall  have  been  fully  and  finally  adjudicated  by a court of
competent jurisdiction, or (ii) all differences shall have been adjusted and all
doubt resolved by agreement among all of the interested persons,  and the Escrow
Agent shall have been  notified  thereof in writing  signed by all such persons.
The rights of the Escrow Agent under this  paragraph are cumulative of all other
rights which it may have by law or otherwise.

         Executed in Dallas, Texas this ___ day of __________, 1999.

BOK FINANCIAL CORPORATION


By: ________________________________                                  
    Stanley A.  Lybarger, Chief Executive Officer


CANYON CREEK FINANCIAL CORPORATION


By: ________________________________                                 
    Charles W. Eisemann, Chairman of the Board




BANK OF TEXAS TRUST COMPANY,
  NATIONAL ASSOCIATION


By: _______________________________                               
    Name:
    Title:

<PAGE>
                                  EXHIBIT "C"


                              EMPLOYMENT AGREEMENT

         This Employment Agreement ("Agreement") is made, effective this ___ day
of ______________,  1999, between Canyon Creek National Bank, a national banking
association  (the "Bank") and Charles O. Rolfe,  Jr., an individual  residing in
Richardson, Texas (the "Executive").

         The Bank and Executive,  in consideration of the promises and covenants
set forth herein (the receipt and adequacy of which is hereby  acknowledged) and
intending to be legally bound hereby, agree as follows:

(1)     Purpose of This Agreement. The purpose of this agreement is as follows:

         (a)      The Bank is a  national  banking  association,  engaged in the
                  banking business in Dallas County, Texas.

         (b)      The  Executive  is currently  serving as  President  and Chief
                  Executive Officer of the Bank. The Executive  currently has no
                  written  agreement of employment  with the Bank, but Executive
                  is currently  receiving salary compensation and other benefits
                  from the Bank  (collectively,  the  "Current  Benefits").  BOK
                  Financial Corporation ("BOKF") is a bank holding company. BOKF
                  owns  indirectly  all of the  issued and  outstanding  capital
                  stock of Bank of Texas,  National Association ("BOT") and BOKF
                  Merger Corporation Number Nine, a Texas corporation.

         (c)      Pursuant  to an  Agreement  and  Plan of  Merger,  dated as of
                  February  19,  1999  (the  "Merger  Agreement"),  among  BOKF,
                  Chaparral  Bancshares,  Inc.  ("Chaparral"),  and  BOK  Merger
                  Corporation  Number Nine, BOKF is acquiring indirect ownership
                  of the Bank (the  "Merger").  Upon and subject to consummation
                  of the  Merger,  the Bank  desires to retain the  services  of
                  Executive,   and  Executive  desires  to  continue  to  render
                  services  to the  Bank.  It is  contemplated  that in the near
                  future, the Bank will be merged into BOT (the "Bank Merger").

         (d)      The  purpose of this  Agreement  is to set forth the terms and
                  conditions   (i)  on  which  the  Bank   shall,   subject   to
                  consummation  of the Merger,  employ  Executive from and after
                  consummation of the Merger and (ii) on which Executive  agrees
                  not to compete with the Bank.

(2)      Employment.  The Bank hereby employs  Executive,  and Executive  hereby
         agrees to work for the Bank, on the following terms and conditions:



          (a)  Until the Bank Merger,  Executive  shall serve as  President  and
               Chief Executive Officer of the Bank,  subject to the direction of
               the Board of  Directors  of the Bank and of the  Chief  Executive
               Officer  of BOT;  provided,  that,  in the  event  of a  conflict
               between the  directions  being given by the Board of Directors of
               the Bank and the Chief Executive Officer of BOT,  Executive shall
               act in accordance  with the  directions of the Board of Directors
               of the Bank. After consummation of the Bank Merger, the Executive
               shall  serve  as  President  of Bank of  Texas -  Richardson  (an
               unincorporated banking division of the Bank).

         (b)      Executive  shall  devote  all  time and  attention  reasonably
                  necessary  to the affairs of the Bank and shall serve the Bank
                  diligently, loyally, and to the best of his ability.

         (c)      Executive shall serve in such other or additional positions as
                  an officer  and/or  director of the Bank as Executive  and the
                  Board  of  Directors  of the Bank  may  mutually  agree or any
                  affiliate  of the Bank as  Executive  and the Chief  Executive
                  Officer  of  BOT  may  mutually  agree;   provided,   however,
                  Executive's residence and place of work shall remain in Dallas
                  County or Collin County, Texas.

         (d)      Notwithstanding  anything  herein to the  contrary,  Executive
                  shall not be precluded from engaging in any charitable, civic,
                  political  or  community   activity  or   membership   in  any
                  professional organization.

(3)      Compensation.  As the sole, full and complete compensation to Executive
         for the performance of all duties of Executive under this Agreement and
         for all services  rendered by Executive to the Bank or to any affiliate
         of the Bank:

         (a)      The Bank shall pay to  Executive  the sum of $150,000 per year
                  payable in installments  in arrears,  less usual and customary
                  payroll  deductions for FICA,  federal and state  withholding,
                  and the  like,  at the  times  and in the  manner in effect in
                  accordance  with the  usual  and  customary  payroll  policies
                  generally  in effect  from  time to time at the Bank  ("Annual
                  Salary").

         (b)      The Bank shall pay and provide to Executive  pension,  thrift,
                  medical  insurance,  disability  insurance plan benefits,  and
                  other  fringe   benefits,   generally  in  effect  for  senior
                  executive   employees   of  BOKF  and  its   affiliates   (the
                  "Additional Benefits").  The pension benefits provided to BOKF
                  employees are fully  described in the official plan  document.
                  Executive   shall  be  credited  with  his  prior  service  at
                  Chaparral  and its  affiliates  in  BOKF's  401k  plan  and in
                  connection  with  the  Additional  Benefits,   other  than  in
                  connection with BOKF's pension plan.


<PAGE>


         (c)      The Bank  may,  from time to time in  Bank's  sole  discretion
                  consistent  with the practices  generally in effect for senior
                  executive  employees  of  BOKF  and  its  affiliates,  pay  or
                  provide, or agree to pay or provide,  Executive a bonus, stock
                  option, or other incentive or performance based  compensation.
                  All such bonus, stock option or other incentive or performance
                  based  compensation,  regardless  of its  nature  (hereinafter
                  called "Performance Compensation") shall not constitute Annual
                  Salary.

         (d)      The  Bank  shall   reimburse   Executive  for  reasonable  and
                  necessary   entertainment,   travel  and  other   expenses  in
                  accordance with BOKF's standard policies in general effect for
                  senior  executive   employees  of  BOKF's   affiliates  (which
                  includes   dues  for  lunch   clubs,   but  does  not  include
                  reimbursement for country club memberships or dues).

         (e)      The Executive shall be allowed vacation,  holidays,  and other
                  employee  benefits not described  above in accordance with the
                  Bank's  standard  policy in general  effect for Bank's  senior
                  executive employees.

         (f)      The  Executive  shall be  considered  for the award of options
                  pursuant  to BOKF's  stock  option  plan on the same  basis as
                  other senior executives of BOKF and its affiliates.

         (g)      Upon  consummation  of the Merger,  the Bank shall transfer to
                  Executive  ownership of that certain  1997  Cadillac  Sedan De
                  Ville  automobile  currently  being  driven by  Executive.  In
                  addition,  it is understood  and agreed that  Executive owns a
                  membership in the Canyon Creek Country Club, although the Bank
                  currently pays the dues owing on such membership.

         (h)      Executive  hereby agrees to accept the foregoing  compensation
                  from and after the date of  consummation of the Merger in lieu
                  of all Current  Benefits  and as the sole,  full and  complete
                  compensation to Executive for the performance of all duties of
                  Executive  under this Agreement and for all services  rendered
                  by Executive to the Bank or any affiliate of the Bank.

(4)      Term of this  Agreement.  The term of this Agreement (the "Term") shall
         commence  (the  "Commencement")  as of the  commencement  of the  first
         pay-roll period immediately  preceding the effective date of the Merger
         and shall terminate on the third anniversary date of the Commencement.

(5)  Termination of This Agreement.  Notwithstanding the provisions of paragraph
     4 of this  Agreement,  this  Agreement  may be  terminated on the following
     terms and conditions:

         (a)      Termination  by Bank for Cause.  The Bank may  terminate  this
                  Agreement for cause on the following terms and conditions:



<PAGE>


                  (i)      The Bank shall be deemed to have  cause to  terminate
                           Executive's  employment  only in one of the following
                           events:

                           (A)      The Executive shall, after one prior written
                                    notice,   willfully  fail  to  substantially
                                    perform his obligations under this Agreement
                                    (it being  understood  that any such failure
                                    resulting from Executive's incapacity due to
                                    physical  or  mental  illness  shall  not be
                                    deemed willful);

                           (B)      Any  intentional  act which is  intended  by
                                    Executive to materially injure the Bank;

                           (C)      Any criminal act involving moral turpitude;

                           (D)      Any dishonest or fraudulent act; or,

                    (E)  Any refusal to obey written orders or  instructions  of
                         the Board of  Directors  of the  Bank,  after one prior
                         written notice,  unless such instructions would require
                         Executive  to  commit an  illegal  act,  could  subject
                         Executive   to  personal   liability,   would   require
                         Executive  to violate the terms of this  Agreement,  or
                         would otherwise be  inconsistent  with the duties of an
                         officer of a national banking association.

               (ii) The  Bank  shall  be  deemed  to  have  cause  to  terminate
                    Executive's  employment  only when a majority of the members
                    of the Board of  Directors  of the Bank finds  that,  in the
                    good faith opinion of such majority, Executive committed any
                    of the acts set  forth in  clauses  (A)  through  (E) of the
                    preceding subparagraph, such finding to have been made after
                    at least ten (10) business  days' notice to Executive and an
                    opportunity for Executive,  together with his counsel, to be
                    heard  before  such  majority.  The  determination  of  such
                    majority, made as set forth above, shall be binding upon the
                    Bank and Executive, absent bad faith or willful misconduct.



<PAGE>


                    (iii)The effective date of a termination  for cause shall be
                         the date of the  action of such  majority  finding  the
                         termination  was  with  cause.  In the  event  the Bank
                         terminates this Agreement for cause, (A) the Bank shall
                         pay Executive  Executive's  then Annual Salary through,
                         but not beyond,  the effective date of the termination,
                         (B) Executive  shall  receive  those  benefits that are
                         accrued  through but not beyond the  effective  date of
                         such termination which are thereafter payable under the
                         terms and provisions of benefit plans then in effect in
                         accordance with paragraph 3 above.

         (b)      Termination By Executive. The Executive may, at any time after
                  the first  anniversary date of the consummation of the Merger,
                  terminate   this   Agreement  on  the   following   terms  and
                  conditions:

                  (i)      The Executive may give written  notice of termination
                           to the Bank.  The  termination  shall be effective on
                           the  fifteenth  (15th)  business  day  following  the
                           notice of termination.

                  (ii)     Upon termination by Executive, the Bank shall have no
                           obligation to Executive  under this Agreement  beyond
                           the  effective  date  of the  termination;  provided,
                           however,  that Executive shall be entitled to receive
                           any benefits,  insured or otherwise,  that  Executive
                           would  otherwise be able to receive under any benefit
                           plan of the Bank of which  Executive is a beneficiary
                           in accordance with paragraph 3.

         (c)      Termination after Bank Merger.  Either party to this Agreement
                  may, at any time after the ninetieth (90th) day after the Bank
                  Merger,  terminate this  Agreement on the following  terms and
                  conditions:

                  (i)      The  party  terminating  this  Agreement  shall  give
                           written  notice of  termination  to the  other  party
                           hereto.  The  termination  shall be  effective on the
                           fifteenth (15th) business day following the notice of
                           termination.

                  (ii)     Upon termination pursuant to this paragraph 5(c), the
                           obligations  of the  Executive  pursuant to paragraph
                           8(a) and the Bank  pursuant to  paragraph  8(b) shall
                           continue for the remaining period of  non-competition
                           set forth in paragraph 8(a).



<PAGE>


(6)      Death of Executive.  In the event of Executive's  death during the term
         of  this  Agreement,  his  estate,  legal  representatives,   or  named
         beneficiaries (as set forth in a writing by Executive  delivered to the
         Bank prior to death) (i) shall be paid  Executive's  Annual  Salary and
         Additional  Benefits for a period equal to the lesser of the  remaining
         term  of  this  agreement  or six  (6)  months  following  the  date of
         Executive's  death and (ii)  shall  receive  those  benefits  which are
         accrued  through the date six (6) months after the date of  Executive's
         death and which are  thereafter  payable under the terms and provisions
         of the  benefit  plans then in effect in  accordance  with  paragraph 3
         above.

(7)      Provisions  Respecting  Illness.  In the event  Executive  is unable to
         perform his duties  under this  Agreement  on a  full-time  basis for a
         period of six (6)  consecutive  months by  reason of  illness  or other
         physical or mental disability, and at or before the end of such period,
         Executive  does not return to work on a full-time  basis,  the Bank may
         terminate this  Agreement  without  further or additional  compensation
         being due  Executive  from the Bank except  annual  salary and benefits
         accrued through the date of such  termination  under benefit plans then
         in effect in accordance with paragraph 3 above.

(8)  Agreement Not to Compete.  The provisions of this paragraph 8 are hereafter
     called the "Non-Competition Agreement".

     (a)  Executive  agrees that for a period of 3 years after the  commencement
          of this Agreement, Executive shall not directly or indirectly (whether
          as an officer, director,  employee,  partner, 5% stockholder or agent)
          (i) engage in the banking  business  generally  or in any  business in
          which the Bank has,  as of the date of such  termination  engaged,  in
          Dallas  County or Collin  County,  Texas,  or (ii) solicit the banking
          business  of any  clients  of Bank or  Bank's  affiliates  or  solicit
          employees of Bank or Bank's  affiliates  to seek  employment  with any
          person or entity engaged in the financial services business except the
          Bank and its affiliates, whether, in either case, such solicitation is
          made within or without the area  described in this paragraph 8, except
          that this Non-Competition  Agreement shall not be binding on Executive
          if the Bank shall have breached its obligations under this Agreement.

     (b)  Except in the event of the termination of Executive's  employment with
          the Bank  pursuant to the  provisions  of paragraph  5(a) or paragraph
          5(b) of this  Agreement,  the Bank  shall pay  Executive  during  such
          period of non-competition (i) 100% of his Annual Salary at the time of
          termination,  for each full calendar month payable on the first day of
          each calendar  month  commencing  with the first calendar month of the
          period of non-competition  and (ii) the Bank shall continue in effect,
          and provide to Executive,  the same or similar  medical  insurance and
          disability  insurance  as provided to Executive  immediately  prior to
          such termination.

     (c)  Executive  agrees that (i) this  Non-Competition  Agreement is entered
          into in  connection  with  the  sale to  BOKF of the  goodwill  of the
          business  of  the  Bank,   (ii)   Executive  is   receiving   valuable
          consideration in the Merger for this Non-Competition  Agreement, (iii)
          the  restrictions  imposed  upon  Executive  by  this  Non-Competition
          Agreement  are  essential  and  necessary to ensure BOKF  acquires the
          goodwill  of the  Bank,  and  (iv)  all  the  restrictions  (including
          particularly the time and geographical  limitations) set forth in this
          Non-Competition Agreement are fair and reasonable.


<PAGE>



     (d)  Executive  agrees  that  any  remedy  at law  for any  breach  of this
          Non-Competition Agreement would be inadequate and, in the event of any
          such  breach,  the  Bank  shall  be  entitled  to both  immediate  and
          permanent  injunctive relief without the necessity of posting any bond
          therefor to preclude  any such breach (in  addition to any remedies of
          law which the Bank may be entitled).

(9) Miscellaneous Provisions. The following miscellaneous provisions shall apply
to this Agreement:

     (a)  All  notices  or  advices  required  or  permitted  to be  given by or
          pursuant  to this  Agreement,  shall  be given  in  writing.  All such
          notices and advices shall be (i) delivered personally,  (ii) delivered
          by facsimile or delivered by U.S. Registered or Certified Mail, Return
          Receipt Requested mail, or (iii) delivered for overnight delivery by a
          nationally  recognized  overnight  courier  service.  Such notices and
          advices shall be deemed to have been given (i) the first  business day
          following  the  date  of  delivery  if  delivered   personally  or  by
          facsimile,  (ii) on the  third  business  day  following  the  date of
          mailing if mailed by U.S. Registered or Certified Mail, Return Receipt
          Requested,  or (iii) on the date of receipt if delivered for overnight
          delivery by a nationally  recognized  overnight  courier service.  All
          such notices and advices and all other communications  related to this
          Agreement shall be given as follows:

                  If to the Bank:

                                    BOK Financial Corporation
                                    P.O. Box 2300
                                    Tulsa, OK 74192
                                    Attention: Stanley A. Lybarger
                                    Telecopy No.: (918) 588-6888

                                    and

                                    Canyon Creek National Bank
                                    333 West Campbell Road
                                    Richardson, Texas 75080
                                    Attention:  Chairman of the Board
                                    Telecopy No.:  (972) 234-8641



<PAGE>


                                    With a Copy to:

                                    Bank of Texas, N. A.
                                    5956 Sherry Lane, Suite 1800
                                    Dallas, Texas   75225
                   Attention: Mr. C. Fred Ball, Jr., President
                          Telecopy No.: (214) 521-9072

                                    and

                                    Frederic Dorwart
                                    Old City Hall
                                    124 East Fourth Street
                                    Tulsa, OK 74103-5010
                                    Telecopy No.: (918) 583-8251

                  If to Executive:

                                    Mr. Charles O. Rolfe, Jr.
                                    ================================
                                    --------------------------------
                                    Telecopy No.: ___________________

                  or to such other  address as the party may have  furnished  to
                  the other parties in accordance  herewith,  except that notice
                  of change of addresses shall be effective only upon receipt.

         (b)      This Agreement is made and executed in Dallas  County,  Texas,
                  and all  actions  or  proceedings  with  respect  to,  arising
                  directly or indirectly in connection  with, out of, related to
                  or from this  Agreement,  shall be litigated in courts  having
                  situs in Dallas County, Texas.

         (c)      This Agreement  shall be subject to, and interpreted by and in
                  accordance   with,  the  laws   (excluding   conflict  of  law
                  provisions) of the State of Texas.

         (d)      This  Agreement  is  the  entire   Agreement  of  the  parties
                  respecting  the  subject  matter  hereof.  There  are no other
                  agreements,  representations  or  warranties,  whether oral or
                  written,  respecting  the  subject  matter  hereof,  except as
                  stated in this Agreement.

         (e)      This  Agreement,  and all the  provisions  of this  Agreement,
                  shall be deemed drafted by all of the parties hereto.



<PAGE>


         (f)      This  Agreement  shall  not  be  interpreted  strictly  for or
                  against  any  party,  but solely in  accordance  with the fair
                  meaning of the  provisions  hereof to effectuate  the purposes
                  and interest of this Agreement.

         (g)      Each party hereto has entered into this Agreement based solely
                  upon the agreements,  representations and warranties expressly
                  set forth herein and upon his own knowledge and investigation.
                  Neither party has relied upon any  representation  or warranty
                  of any other party hereto except any such  representations  or
                  warranties as are expressly set forth herein.

         (h)      Each of the persons  signing below on behalf of a party hereto
                  represents  and  warrants  that he or she has  full  requisite
                  power and  authority to execute and deliver this  Agreement on
                  behalf of the  parties  for whom he or she is  signing  and to
                  bind such party to the terms and conditions of this Agreement.

         (i)      This Agreement may be executed in counterparts,  each of which
                  shall be deemed  an  original.  This  Agreement  shall  become
                  effective  only  when all of the  parties  hereto  shall  have
                  executed the original or  counterpart  hereof.  This Agreement
                  may be executed and delivered by a facsimile transmission of a
                  counterpart signature page hereof.

         (j)      In any  action  brought  by a  party  hereto  to  enforce  the
                  obligations of any other party hereto,  the  prevailing  party
                  shall be entitled to collect from the  opposing  party to such
                  action such party's reasonable  litigation costs and attorneys
                  fees and expenses  (including court costs,  reasonable fees of
                  accountants and experts,  and other expenses incidental to the
                  litigation).

         (k)      This  Agreement  shall be binding  upon and shall inure to the
                  benefit of the parties  and their  respective  successors  and
                  assigns.  The Bank agrees that if it merges,  consolidates  or
                  combines with any other  business  entity,  it shall cause the
                  succeeding or  continuing  corporation  or business  entity to
                  expressly assume and confirm in writing the obligations of the
                  Bank under this Agreement.

         (l)      This is not a third party  beneficiary  contract,  except BOKF
                  (including  each  affiliate  thereof)  shall be a third  party
                  beneficiary of this Agreement.  No person or entity other than
                  a party signing this Agreement and those designated as a third
                  party  beneficiary  herein  shall have any  rights  under this
                  Agreement.

         (m)      This  Agreement  may be amended or modified  only in a writing
                  which specifically references this Agreement.



<PAGE>


         (n)      A party to this  Agreement  may decide or fail to require full
                  or timely  performance  of any  obligation  arising under this
                  Agreement.  The  decision  or  failure  of a party  hereto  to
                  require full or timely  performance of any obligation  arising
                  under  this  Agreement  (whether  on a single  occasion  or on
                  multiple  occasions)  shall not be deemed a waiver of any such
                  obligation.  No such  decisions or failures shall give rise to
                  any claim of estoppel, laches, course of dealing, amendment of
                  this  Agreement by course of dealing,  or other defense of any
                  nature to any obligation arising hereunder.

         (o)      In  the  event  any  provision  of  this  Agreement,   or  the
                  application  of  such  provision  to  any  person  or  set  of
                  circumstances, shall be determined to be invalid, unlawful, or
                  unenforceable  to any extent for any reason,  the remainder of
                  this  Agreement,  and the  application  of such  provision  to
                  persons  or  circumstances  other than those as to which it is
                  determined to be invalid,  unlawful,  or unenforceable,  shall
                  not be affected and shall  continue to be  enforceable  to the
                  fullest extent permitted by law.

         Dated and effective the date first set forth above.

                                                      CANYON CREEK NATIONAL BANK


                                                      By: _____________________
                                                          Charles W. Eisemann,
                                                          Chairman of the Board

                                                          ______________________
                                                          Charles O. Rolfe, Jr.


<PAGE>
                                  EXHIBIT "D"
                              EMPLOYMENT AGREEMENT

         This Employment Agreement ("Agreement") is made, effective this ___ day
of ______________,  1999, between Canyon Creek National Bank, a national banking
association  (the  "Bank")  and John B.  Whisenant,  an  individual  residing in
McKinney, Texas (the "Executive").

         The Bank and Executive,  in consideration of the promises and covenants
set forth herein (the receipt and adequacy of which is hereby  acknowledged) and
intending to be legally bound hereby, agree as follows:

(1)    Purpose of This Agreement.  The purpose of this agreement is as follows:

         (a)      The Bank is a  national  banking  association,  engaged in the
                  banking business in Dallas County, Texas.

         (b)      The  Executive  is  currently  serving  as  President  of  the
                  McKinney  Branch of the Bank.  The Executive  currently has no
                  written  agreement of employment  with the Bank, but Executive
                  is currently  receiving salary compensation and other benefits
                  from the Bank  (collectively,  the  "Current  Benefits").  BOK
                  Financial Corporation ("BOKF") is a bank holding company. BOKF
                  owns  indirectly  all of the  issued and  outstanding  capital
                  stock of Bank of Texas,  National Association ("BOT") and BOKF
                  Merger Corporation Number Nine, a Texas corporation.

         (c)      Pursuant  to an  Agreement  and  Plan of  Merger,  dated as of
                  February  19,  1999  (the  "Merger  Agreement"),  among  BOKF,
                  Chaparral  Bancshares,  Inc.  ("Chaparral"),  and  BOK  Merger
                  Corporation  Number Nine, BOKF is acquiring indirect ownership
                  of the Bank (the  "Merger").  Upon and subject to consummation
                  of the  Merger,  the Bank  desires to retain the  services  of
                  Executive,   and  Executive  desires  to  continue  to  render
                  services  to the  Bank.  It is  contemplated  that in the near
                  future, the Bank will be merged into BOT (the "Bank Merger").

         (d)      The  purpose of this  Agreement  is to set forth the terms and
                  conditions   (i)  on  which  the  Bank   shall,   subject   to
                  consummation  of the Merger,  employ  Executive from and after
                  consummation of the Merger and (ii) on which Executive  agrees
                  not to compete with the Bank.

(2)      Employment.  The Bank hereby employs  Executive,  and Executive  hereby
         agrees to work for the Bank, on the following terms and conditions:


<PAGE>
                                                

          (a)  Until the Bank Merger,  Executive shall serve as President of the
               McKinney  Branch of the Bank,  subject  to the  direction  of the
               Board of Directors of the Bank and of the Chief Executive Officer
               of BOT;  provided,  that, in the event of a conflict  between the
               directions  being given by the Board of Directors of the Bank and
               the  Chief  Executive  Officer  of BOT,  Executive  shall  act in
               accordance  with the  directions of the Board of Directors of the
               Bank. After  consummation of the Bank Merger, the Executive shall
               serve as President of Bank of Texas - McKinney (an unincorporated
               banking division of the Bank).

         (b)      Executive  shall  devote  all  time and  attention  reasonably
                  necessary  to the affairs of the Bank and shall serve the Bank
                  diligently, loyally, and to the best of his ability.

         (c)      Executive shall serve in such other or additional positions as
                  an officer  and/or  director of the Bank as Executive  and the
                  Board  of  Directors  of the Bank  may  mutually  agree or any
                  affiliate  of the Bank as  Executive  and the Chief  Executive
                  Officer  of  BOT  may  mutually  agree;   provided,   however,
                  Executive's residence and place of work shall remain in Collin
                  County, Texas.

         (d)      Notwithstanding  anything  herein to the  contrary,  Executive
                  shall not be precluded from engaging in any charitable, civic,
                  political  or  community   activity  or   membership   in  any
                  professional organization.

(3)      Compensation.  As the sole, full and complete compensation to Executive
         for the performance of all duties of Executive under this Agreement and
         for all services  rendered by Executive to the Bank or to any affiliate
         of the Bank:

         (a)      The Bank shall pay to  Executive  the sum of $120,000 per year
                  payable in installments  in arrears,  less usual and customary
                  payroll  deductions for FICA,  federal and state  withholding,
                  and the  like,  at the  times  and in the  manner in effect in
                  accordance  with the  usual  and  customary  payroll  policies
                  generally  in effect  from  time to time at the Bank  ("Annual
                  Salary").

          (b)  The Bank shall pay and  provide  to  Executive  pension,  thrift,
               medical insurance,  disability insurance plan benefits, and other
               fringe  benefits,   generally  in  effect  for  senior  executive
               employees of BOKF and its affiliates (the "Additional Benefits").
               The  pension  benefits  provided  to  BOKF  employees  are  fully
               described  in the  official  plan  document.  Executive  shall be
               credited with his prior  service at Chaparral and its  affiliates
               in  BOKF's  401k  plan  and in  connection  with  the  Additional
               Benefits, other than in connection with BOKF's pension plan.


<PAGE>


         (c)      The Bank  may,  from time to time in  Bank's  sole  discretion
                  consistent  with the practices  generally in effect for senior
                  executive  employees  of  BOKF  and  its  affiliates,  pay  or
                  provide, or agree to pay or provide,  Executive a bonus, stock
                  option, or other incentive or performance based  compensation.
                  All such bonus, stock option or other incentive or performance
                  based  compensation,  regardless  of its  nature  (hereinafter
                  called "Performance Compensation") shall not constitute Annual
                  Salary.

         (d)      The  Bank  shall   reimburse   Executive  for  reasonable  and
                  necessary   entertainment,   travel  and  other   expenses  in
                  accordance with BOKF's standard policies in general effect for
                  senior  executive   employees  of  BOKF's   affiliates  (which
                  includes   dues  for  lunch   clubs,   but  does  not  include
                  reimbursement for country club memberships or dues).

         (e)      The Executive shall be allowed vacation,  holidays,  and other
                  employee  benefits not described  above in accordance with the
                  Bank's  standard  policy in general  effect for Bank's  senior
                  executive employees.

         (f)      The  Executive  shall be  considered  for the award of options
                  pursuant  to BOKF's  stock  option  plan on the same  basis as
                  other senior executives of BOKF and its affiliates.

         (g)      Executive  hereby agrees to accept the foregoing  compensation
                  from and after the date of  consummation of the Merger in lieu
                  of all Current  Benefits  and as the sole,  full and  complete
                  compensation to Executive for the performance of all duties of
                  Executive  under this Agreement and for all services  rendered
                  by Executive to the Bank or any affiliate of the Bank.

(4)      Term of this  Agreement.  The term of this Agreement (the "Term") shall
         commence  (the  "Commencement")  as of the  commencement  of the  first
         pay-roll period immediately  preceding the effective date of the Merger
         and shall terminate on the second anniversary date of the Commencement.

(5)  Termination of This Agreement.  Notwithstanding the provisions of paragraph
     4 of this  Agreement,  this  Agreement  may be  terminated on the following
     terms and conditions:

     (a)  Termination  by Bank for Cause.  The Bank may terminate this Agreement
          for cause on the following terms and conditions:

          (i)  The Bank shall be deemed to have cause to  terminate  Executive's
               employment only in one of the following events:


<PAGE>

               (A)  The  Executive  shall,   after  one  prior  written  notice,
                    willfully  fail to  substantially  perform  his  obligations
                    under  this  Agreement  (it being  understood  that any such
                    failure   resulting  from  Executive's   incapacity  due  to
                    physical or mental illness shall not be deemed willful);

               (B)  Any  intentional  act  which is  intended  by  Executive  to
                    materially injure the Bank;

               (C)  Any criminal act involving moral turpitude;

               (D)  Any dishonest or fraudulent act; or,

               (E)  Any refusal to obey written  orders or  instructions  of the
                    Board of  Directors  of the Bank,  after  one prior  written
                    notice,  unless such instructions would require Executive to
                    commit an illegal act,  could subject  Executive to personal
                    liability,  would require  Executive to violate the terms of
                    this Agreement,  or would otherwise be inconsistent with the
                    duties of an officer of a national banking association.

                    (ii) The Bank  shall be  deemed to have  cause to  terminate
                         Executive's  employment  only  when a  majority  of the
                         members  of the Board of  Directors  of the Bank  finds
                         that,  in the  good  faith  opinion  of such  majority,
                         Executive  committed  any  of the  acts  set  forth  in
                         clauses (A) through (E) of the preceding  subparagraph,
                         such  finding to have been made after at least ten (10)
                         business  days' notice to Executive and an  opportunity
                         for Executive,  together with his counsel,  to be heard
                         before  such  majority.   The   determination  of  such
                         majority,  made as set forth  above,  shall be  binding
                         upon  the  Bank  and  Executive,  absent  bad  faith or
                         willful misconduct.

                    (iii)The effective date of a termination  for cause shall be
                         the date of the  action of such  majority  finding  the
                         termination  was  with  cause.  In the  event  the Bank
                         terminates this Agreement for cause, (A) the Bank shall
                         pay Executive  Executive's  then Annual Salary through,
                         but not beyond,  the effective date of the termination,
                         (B) Executive  shall  receive  those  benefits that are
                         accrued  through but not beyond the  effective  date of
                         such termination which are thereafter payable under the
                         terms and provisions of benefit plans then in effect in
                         accordance with paragraph 3 above.


<PAGE>


     (b)  Termination  By  Executive.  The  Executive  may, at anytime after the
          first  anniversary date of the  consummation of the Merger,  terminate
          this Agreement on the following terms and conditions:

          (i)  The Executive may give written notice of termination to the Bank.
               The  termination  shall  be  effective  on the  fifteenth  (15th)
               business day following the notice of termination.

          (ii) Upon termination by Executive, the Executive shall be entitled to
               receive any benefits,  insured or otherwise, that Executive would
               otherwise  be able to receive  under any benefit plan of the Bank
               of which  Executive is a beneficiary in accordance with paragraph
               3.

(6)      Death of Executive.  In the event of Executive's  death during the term
         of  this  Agreement,  his  estate,  legal  representatives,   or  named
         beneficiaries (as set forth in a writing by Executive  delivered to the
         Bank prior to death) (i) shall be paid  Executive's  Annual  Salary and
         Additional  Benefits for a period equal to the lesser of the  remaining
         term  of  this  agreement  or six  (6)  months  following  the  date of
         Executive's  death and (ii)  shall  receive  those  benefits  which are
         accrued  through the date six (6) months after the date of  Executive's
         death and which are  thereafter  payable under the terms and provisions
         of the  benefit  plans then in effect in  accordance  with  paragraph 3
         above.

(7)      Provisions  Respecting  Illness.  In the event  Executive  is unable to
         perform his duties  under this  Agreement  on a  full-time  basis for a
         period of six (6)  consecutive  months by  reason of  illness  or other
         physical or mental disability, and at or before the end of such period,
         Executive  does not return to work on a full-time  basis,  the Bank may
         terminate this  Agreement  without  further or additional  compensation
         being due  Executive  from the Bank except  annual  salary and benefits
         accrued through the date of such  termination  under benefit plans then
         in effect in accordance with paragraph 3 above.

(8)  Agreement Not to Compete.  The provisions of this paragraph 8 are hereafter
     called the "Non-Competition Agreement".



<PAGE>


     (a)  Executive  agrees that for a period of 12 months after the termination
          of  Executive's   employment  with  Bank,  for  whatever  reason  such
          employment may cease and whether for cause or without cause, Executive
          shall not  directly or  indirectly  (whether as an officer,  director,
          employee,  partner, 5% stockholder or agent) (i) engage in the banking
          business generally or in any business in which the Bank has, as of the
          date of such  termination  engaged,  in Collin County,  Texas, or (ii)
          solicit  the  banking  business  of any  clients  of  Bank  or  Bank's
          affiliates or solicit  employees of Bank or Bank's  affiliates to seek
          employment with any person or entity engaged in the financial services
          business except the Bank and its affiliates,  whether, in either case,
          such solicitation is made within or without the area described in this
          paragraph 8, except that this  Non-Competition  Agreement shall not be
          binding on Executive if the Bank shall have  breached its  obligations
          under this Agreement.

     (b)  The Bank shall pay Executive during such period of non-competition (i)
          50% of his  Annual  Salary at the time of  termination,  for each full
          calendar  month  payable  on the  first  day of  each  calendar  month
          commencing   with  the  first   calendar   month  of  the   period  of
          non-competition  and (ii) the  Bank  shall  continue  in  effect,  and
          provide  to  Executive,  the same or  similar  medical  insurance  and
          disability  insurance  as provided to Executive  immediately  prior to
          such termination.

     (c)  Executive  agrees that (i) this  Non-Competition  Agreement is entered
          into in  connection  with  the  sale to  BOKF of the  goodwill  of the
          business  of  the  Bank,   (ii)   Executive  is   receiving   valuable
          consideration in the Merger for this Non-Competition  Agreement, (iii)
          the  restrictions  imposed  upon  Executive  by  this  Non-Competition
          Agreement  are  essential  and  necessary to ensure BOKF  acquires the
          goodwill  of the  Bank,  and  (iv)  all  the  restrictions  (including
          particularly the time and geographical  limitations) set forth in this
          Non-Competition Agreement are fair and reasonable.

     (d)  Executive  agrees  that  any  remedy  at law  for any  breach  of this
          Non-Competition Agreement would be inadequate and, in the event of any
          such  breach,  the  Bank  shall  be  entitled  to both  immediate  and
          permanent  injunctive relief without the necessity of posting any bond
          therefor to preclude  any such breach (in  addition to any remedies of
          law which the Bank may be entitled).

(9)  Miscellaneous  Provisions.  The following  miscellaneous  provisions  shall
     apply to this Agreement:

     (a)  All  notices  or  advices  required  or  permitted  to be  given by or
          pursuant  to this  Agreement,  shall  be given  in  writing.  All such
          notices and advices shall be (i) delivered personally,  (ii) delivered
          by facsimile or delivered by U.S. Registered or Certified Mail, Return
          Receipt Requested mail, or (iii) delivered for overnight delivery by a
          nationally  recognized  overnight  courier  service.  Such notices and
          advices shall be deemed to have been given (i) the first  business day
          following  the  date  of  delivery  if  delivered   personally  or  by
          facsimile,  (ii) on the  third  business  day  following  the  date of
          mailing if mailed by U.S. Registered or Certified Mail, Return Receipt
          Requested,  or (iii) on the date of receipt if delivered for overnight
          delivery by a nationally  recognized  overnight  courier service.  All
          such notices and advices and all other communications  related to this
          Agreement shall be given as follows:

                  If to the Bank:

<PAGE>


                                    BOK Financial Corporation
                                    P.O. Box 2300
                                    Tulsa, OK 74192
                                    Attention: Stanley A. Lybarger
                                    Telecopy No.: (918) 588-6888

                                    and

                                    Canyon Creek National Bank
                                    333 West Campbell Road
                                    Richardson, Texas 75080
                                    Attention:  Chairman of the Board
                                    Telecopy No.:  (972) 234-8641

                                    With a Copy to:

                                    Bank of Texas, N.A.
                                    5956 Sherry Lane, Suite 1800
                                    Dallas, Texas   75225
                   Attention: Mr. C. Fred Ball, Jr., President
                          Telecopy No.: (214) 521-9072

                                    and

                                    Frederic Dorwart
                                    Old City Hall
                                    124 East Fourth Street
                                    Tulsa, OK 74103-5010
                                    Telecopy No.: (918) 583-8251

                  If to Executive:

                                    John B. Whisenant
                                    --------------------------------
                                    --------------------------------
                                    Telecopy No.: ___________________

                  or to such other  address as the party may have  furnished  to
                  the other parties in accordance  herewith,  except that notice
                  of change of addresses shall be effective only upon receipt.

         (b)      This Agreement is made and executed in Dallas  County,  Texas,
                  and all  actions  or  proceedings  with  respect  to,  arising
                  directly or indirectly in connection  with, out of, related to
                  or from this  Agreement,  shall be litigated in courts  having
                  situs in Dallas County, Texas.


<PAGE>


         (c)      This Agreement  shall be subject to, and interpreted by and in
                  accordance   with,  the  laws   (excluding   conflict  of  law
                  provisions) of the State of Texas.

         (d)      This  Agreement  is  the  entire   Agreement  of  the  parties
                  respecting  the  subject  matter  hereof.  There  are no other
                  agreements,  representations  or  warranties,  whether oral or
                  written,  respecting  the  subject  matter  hereof,  except as
                  stated in this Agreement.

         (e)      This  Agreement,  and all the  provisions  of this  Agreement,
                  shall be deemed drafted by all of the parties hereto.

         (f)      This  Agreement  shall  not  be  interpreted  strictly  for or
                  against  any  party,  but solely in  accordance  with the fair
                  meaning of the  provisions  hereof to effectuate  the purposes
                  and interest of this Agreement.

         (g)      Each party hereto has entered into this Agreement based solely
                  upon the agreements,  representations and warranties expressly
                  set forth herein and upon his own knowledge and investigation.
                  Neither party has relied upon any  representation  or warranty
                  of any other party hereto except any such  representations  or
                  warranties as are expressly set forth herein.

         (h)      Each of the persons  signing below on behalf of a party hereto
                  represents  and  warrants  that he or she has  full  requisite
                  power and  authority to execute and deliver this  Agreement on
                  behalf of the  parties  for whom he or she is  signing  and to
                  bind such party to the terms and conditions of this Agreement.

         (i)      This Agreement may be executed in counterparts,  each of which
                  shall be deemed  an  original.  This  Agreement  shall  become
                  effective  only  when all of the  parties  hereto  shall  have
                  executed the original or  counterpart  hereof.  This Agreement
                  may be executed and delivered by a facsimile transmission of a
                  counterpart signature page hereof.

         (j)      In any  action  brought  by a  party  hereto  to  enforce  the
                  obligations of any other party hereto,  the  prevailing  party
                  shall be entitled to collect from the  opposing  party to such
                  action such party's reasonable  litigation costs and attorneys
                  fees and expenses  (including court costs,  reasonable fees of
                  accountants and experts,  and other expenses incidental to the
                  litigation).

         (k)      This  Agreement  shall be binding  upon and shall inure to the
                  benefit of the parties  and their  respective  successors  and
                  assigns.  The Bank agrees that if it merges,  consolidates  or
                  combines with any other  business  entity,  it shall cause the
                  succeeding or  continuing  corporation  or business  entity to
                  expressly assume and confirm in writing the obligations of the
                  Bank under this Agreement.



<PAGE>


         (l)      This is not a third party  beneficiary  contract,  except BOKF
                  (including  each  affiliate  thereof)  shall be a third  party
                  beneficiary of this Agreement.  No person or entity other than
                  a party signing this Agreement and those designated as a third
                  party  beneficiary  herein  shall have any  rights  under this
                  Agreement.

         (m)      This  Agreement  may be amended or modified  only in a writing
                  which specifically references this Agreement.

         (n)      A party to this  Agreement  may decide or fail to require full
                  or timely  performance  of any  obligation  arising under this
                  Agreement.  The  decision  or  failure  of a party  hereto  to
                  require full or timely  performance of any obligation  arising
                  under  this  Agreement  (whether  on a single  occasion  or on
                  multiple  occasions)  shall not be deemed a waiver of any such
                  obligation.  No such  decisions or failures shall give rise to
                  any claim of estoppel, laches, course of dealing, amendment of
                  this  Agreement by course of dealing,  or other defense of any
                  nature to any obligation arising hereunder.

         (o)      In  the  event  any  provision  of  this  Agreement,   or  the
                  application  of  such  provision  to  any  person  or  set  of
                  circumstances, shall be determined to be invalid, unlawful, or
                  unenforceable  to any extent for any reason,  the remainder of
                  this  Agreement,  and the  application  of such  provision  to
                  persons  or  circumstances  other than those as to which it is
                  determined to be invalid,  unlawful,  or unenforceable,  shall
                  not be affected and shall  continue to be  enforceable  to the
                  fullest extent permitted by law.

         Dated and effective the date first set forth above.

                                                CANYON CREEK NATIONAL BANK


                                                 By: __________________________
                                                     Charles W. Eisemann,
                                                     Chairman of the Board



                                                     __________________________
                                                     John B. Whisenant

<PAGE>

                                  EXHIBIT "E"

                            NONCOMPETITION AGREEMENT

         This  Noncompetition  Agreement (the  "Agreement")  is made and entered
into as of the ______ day of  ___________,  1999,  by and between  Canyon  Creek
National  Bank,  a national  banking  association  (the  "Bank")  and Charles W.
Eisemann, an individual resident of the State of Texas ("Eisemann").

                                    RECITALS

         WHEREAS,  pursuant  to an  Agreement  and Plan of  Merger,  dated as of
February  19, 1999 (the "Merger  Agreement"),  among BOK  Financial  Corporation
("BOKF"),  Chaparral  Bancshares,  Inc., and BOK Merger Corporation Number Nine,
BOKF is acquiring indirect ownership of the Bank (the "Merger"); and

         WHEREAS,   in  connection  with   consummation   of  the   transactions
contemplated by the Merger Agreement, the Bank and Eisemann have agreed to enter
into this Noncompetition Agreement.

         NOW,  THEREFORE,  in consideration of the premises and mutual covenants
contained herein and intending to be legally bound hereby, the Bank and Eisemann
agree as follows:

         1.       Noncompete Covenants.

                  (a)  Eisemann  agrees that for a period of 24 months after the
date of  consummation  of the Merger,  Eisemann shall not directly or indirectly
(whether as an officer,  director,  employee,  partner, 5% stockholder or agent)
(i) engage in the banking  business  generally  or in any  business in which the
Bank has, as of the date of the Merger engaged, in Dallas County, Texas, or (ii)
solicit the banking  business  of any  clients of Bank or Bank's  affiliates  or
solicit  employees  of Bank or Bank's  affiliates  to seek  employment  with any
person or entity engaged in the financial  services business except the Bank and
its affiliates,  whether,  in either case,  such  solicitation is made within or
without the area described in this  paragraph,  except that this Agreement shall
not be binding on Eisemann if the Bank shall have breached its obligations under
this Agreement.

                  (b) For and in consideration of his obligations hereunder, the
Bank shall pay  Eisemann  $1,000 in a lump sum payment to be made as of the time
the Merger is effective.

                  (c) Eisemann agrees that (i) this Noncompetition  Agreement is
entered into in connection with the sale to BOKF of the goodwill of the business
of the Bank, (ii) Eisemann is receiving valuable consideration in the Merger for
this Noncompetition  Agreement,  (iii) the restrictions imposed upon Eisemann by
this  Noncompetition  Agreement  are  essential  and  necessary  to ensure  BOKF
acquires  the  goodwill of the Bank,  and (iv) all the  restrictions  (including
particularly  the  time  and   geographical   limitations)  set  forth  in  this
Noncompetition Agreement are fair and reasonable.


         2.  Injunctive  Relief.  Eisemann agrees that any remedy at law for any
breach of this Noncompetition Agreement would be inadequate and, in the event of
any such  breach,  the Bank shall be entitled to both  immediate  and  permanent
injunctive relief without the necessity of posting any bond therefor to preclude
any such  breach  (in  addition  to any  remedies  of law  which the Bank may be
entitled).

         3. Assignability.  This Agreement shall not be assigned by either party
without the prior written consent of the other party.

         4. Parties Bound. This Agreement shall be binding upon and inure to the
benefit  of the  parties  hereto  and their  respective  legal  representatives,
successors and assigns, except as otherwise expressly provided herein.

         5.  Texas  Law to  Apply.  This  Agreement  shall be  subject  to,  and
interpreted  by and in  accordance  with,  the laws  (excluding  conflict of law
provisions) of the State of Texas. This Agreement is made and executed in Dallas
County,  Texas, and all actions or proceedings with respect to, arising directly
or indirectly in connection  with,  out of,  related to or from this  Agreement,
shall be litigated in courts having situs in Dallas County, Texas.

         6. Legal Construction. In the event any provision of this Agreement, or
the application of such provision to any person or set of  circumstances,  shall
be determined to be invalid,  unlawful,  or  unenforceable to any extent for any
reason,  the remainder of this Agreement,  and the application of such provision
to persons or circumstances  other than those as to which it is determined to be
invalid, unlawful, or unenforceable, shall not be affected and shall continue to
be enforceable to the fullest extent permitted by law.

         7. Notice.  All notices or advices required or permitted to be given by
or pursuant to this Agreement,  shall be given in writing.  All such notices and
advices  shall be (i)  delivered  personally,  (ii)  delivered  by  facsimile or
delivered by U.S.  Registered or Certified Mail,  Return Receipt Requested mail,
or (iii) delivered for overnight delivery by a nationally  recognized  overnight
courier service. Such notices and advices shall be deemed to have been given (i)
the first business day following the date of delivery if delivered personally or
by  facsimile,  (ii) on the third  business day following the date of mailing if
mailed by U.S. Registered or Certified Mail, Return Receipt Requested,  or (iii)
on the date of receipt if  delivered  for  overnight  delivery  by a  nationally
recognized overnight courier service. All such notices and advices and all other
communications related to this Agreement shall be given as follows:

                  If to the Bank:

                                    BOK Financial Corporation
                                    P.O. Box 2300
                                    Tulsa, OK 74192
                                    Attention: Stanley A. Lybarger
                                    Telecopy No.: (918) 588-6888



<PAGE>


                                    and

                                    Bank of Texas, N.A.
                                    5956 Sherry Lane, Suite 1800
                                    Dallas, Texas 75225
                   Attention: Mr. C. Fred Ball, Jr., President
                          Telecopy No.: (214) 521-9072

                                    and

                                    Canyon Creek National Bank
                                    333 West Campbell Road
                                    Richardson, Texas 75080
                                    Attention:  Chairman of the Board
                                    Telecopy No.:  (972) 234-8641

                                    With a Copy to:

                                    Frederic Dorwart
                                    Old City Hall
                                    124 East Fourth Street
                                    Tulsa, OK 74103-5010
                                    Telecopy No.: (918) 583-8251

                  If to Eisemann:

                                    ------------------------------
                                    ================================
                                    --------------------------------
                                    Telecopy No.: __________________

or to such other address as the party may have furnished to the other parties in
accordance  herewith,  except  that  notice  of  change  of  addresses  shall be
effective only upon receipt.

         8. Entire  Agreement.  This  Agreement  is the entire  Agreement of the
parties  respecting the subject matter  hereof.  There are no other  agreements,
representations or warranties,  whether oral or written,  respecting the subject
matter hereof, except as stated in this Agreement.

         9. Counterparts.  This Agreement may be executed in counterparts,  each
of which shall be deemed an original. This Agreement shall become effective only
when all of the parties  hereto shall have executed the original or  counterpart
hereof. This Agreement may be executed and delivered by a facsimile transmission
of a counterpart signature page hereof.



<PAGE>


         IN WITNESS WHEREOF,  the undersigned have executed this Agreement as of
the date first above written.


                                               _________________________________
                                               Charles W. Eisemann



                                            CANYON CREEK NATIONAL BANK


                                            By:________________________________
                                                Charles O. Rolfe, Jr., President


                               

                                   EXHIBIT "F"

                                ESCROW AGREEMENT


         This   ESCROW   AGREEMENT   has  been   executed   this   ____  day  of
_______________,  1999, by and between BOK Financial Corporation  ("BOKF"),  the
shareholders of Chaparral  Bancshares,  Inc. (the  "Shareholders"),  and Bank of
Texas Trust Company, National Association (the "Escrow Agent").

         BOKF has deposited in escrow with the Escrow Agent $400,000 pursuant to
that certain  Agreement and Plan of Merger dated as of February 19, 1999,  among
BOKF, BOKF Merger Corporation Number Nine, and Chaparral  Bancshares,  Inc. (the
"Merger Agreement"). The parties agree that this escrow shall be administered in
accordance with Section 11.2 of the Merger Agreement, a true and correct copy of
which is attached hereto and incorporated herein by this reference. BOKF and the
Agents (as  defined  in Section  11.2 of the  Merger  Agreement)  shall  jointly
provide all notices to the Escrow  Agent  required by Section 11.2 of the Merger
Agreement  to fulfil the terms and  conditions  of the Escrow  Account,  and the
Escrow Agent shall act only pursuant to the joint written  instructions  of BOKF
and the Agents.

         The  parties  to  this  Escrow   Agreement  agree  that  the  following
provisions  shall  control  with  respect  to the  rights  duties,  liabilities,
privileges and immunities of the Escrow Agent.

         (a) The Escrow Agent is not a party to, and is not bound by, or charged
with notice of, any agreement out of which this escrow may arise.

         (b) The Escrow Agent acts  hereunder as a depository  only,  and is not
responsible or liable in any manner whatever for the  sufficiency,  correctness,
genuineness  or  validity  of the  subject  matter  of the  escrow,  or any part
thereof,  or for the form or execution thereof, or for the identity or authority
of any person  executing  or  depositing  it.  The Escrow  Agent will not render
investment advice with respect to the subject matter of this escrow.

         (c) In the event the Escrow Agent  becomes  involved in  litigation  in
connection  with this escrow,  the  undersigned  jointly and severally  agree to
indemnify  and save the Escrow  Agent  harmless  from all loss,  cost,  damages,
expenses  and  attorney's  fees  suffered or  incurred by the Escrow  Agent as a
result thereof.

         (d) The Escrow  Agent  shall be  protected  in acting  upon any written
notice, request, waiver, consent, certificate, receipt, authorization,  power of
attorney  or other  paper or  document  which  the  Escrow  Agent in good  faith
believes to be genuine and what it purports to be.

         (e) The Escrow Agent shall not be liable for anything that it may do or
refrain from doing in connection  herewith,  except its own gross  negligence or
willful misconduct.



<PAGE>


         (f) The Escrow Agent may consult with legal counsel in the event of any
dispute or question as to the  construction  of any of the provisions  hereof or
its  duties  hereunder,  and it shall  incur  no  liability  and  shall be fully
protected  in acting in  accordance  with the opinion and  instructions  of such
counsel.

         (g) In the event of any disagreement between any of the parties to this
agreement,  or  between  them or  either  of any of them and any  other  person,
resulting in adverse claims or demands being made in connection with the subject
matter of the escrow,  or in the event that the Escrow Agent,  in good faith, be
in doubt as to what action it should take  hereunder,  the Escrow  Agent may, at
its option, refuse to comply with any claims or demands on it, or refuse to take
any other action hereunder, so long as such disagreement continues or such doubt
exists, and in any such event, the Escrow Agent shall not be or become liable in
any way or to any person for its failure or refusal to act, and the Escrow Agent
shall be entitled to continue so to refrain  from acting until (i) the rights of
all  parties  shall  have  been  fully  and  finally  adjudicated  by a court of
competent jurisdiction, or (ii) all differences shall have been adjusted and all
doubt resolved by agreement among all of the interested persons,  and the Escrow
Agent shall have been  notified  thereof in writing  signed by all such persons.
The rights of the Escrow Agent under this  paragraph are cumulative of all other
rights which it may have by law or otherwise.

         Executed in Dallas, Texas this ___ day of __________, 1999.

BOK FINANCIAL CORPORATION


By: ____________________________________________                               
   Stanley A.  Lybarger, Chief Executive Officer


SHAREHOLDERS


By: ____________________________________________                            
    Charles W. Eisemann, as Chairman of the Board
    of Directors of Chaparral Bancshares, Inc.



BANK OF TEXAS TRUST COMPANY,
  NATIONAL ASSOCIATION


By: ___________________________                                               
    Name:
    Title:



