

                                                                    EXHIBIT 99.1

                                                  As Amended on January 27, 2000

                       ST. MARY LAND & EXPLORATION COMPANY
                       -----------------------------------

                                STOCK OPTION PLAN
                                -----------------

                                    ARTICLE I
                            ESTABLISHMENT AND PURPOSE
                            -------------------------

         1.1 Establishment.  St. Mary Land &  Exploration  Company,  a Delaware
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corporation  (the  "Company"),  hereby  establishes  a stock option plan for key
employees,  consultants  and members of the Board of Directors of the Company or
of a subsidiary  of the  Company,  providing  material  services to the Company,
which shall be known as the ST. MARY LAND &  EXPLORATION  COMPANY  STOCK  OPTION
PLAN (the "Plan"). The Company shall enter into Option agreements with Optionees
pursuant to the Plan.

         1.2 Purpose. The purpose of the Plan is to enhance shareholder value by
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attracting,  retaining and motivating key employees,  consultants and members of
the Board of  Directors  of the  Company and of a  subsidiary  of the Company by
providing  them with a means to acquire a proprietary  interest in the Company's
success.

                                   ARTICLE II
                          ELIGIBILITY AND PARTICIPATION
                          -----------------------------

         All current and former employees,  consultants and members of the Board
of Directors of the Company (the "Board"), and of any subsidiary of the Company,
are  eligible to  participate  in the Plan and receive  Options  under the Plan.
Optionees under the Plan shall be selected by the Board, in its sole discretion,
from among those current and former  employees,  consultants  and members of the
Board of the Company, and of any subsidiary of the Company,  who, in the opinion
of the  Board,  are or  were  in a  position  to  contribute  materially  to the
Company's continued growth and development and to its long-term success.

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                                   ARTICLE III
                                 ADMINISTRATION
                                 --------------

     Administration.  The Board shall be responsible for administering the Plan.
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          (a) The Board is  authorized  to  interpret  the Plan;  to  prescribe,
     amend,  and rescind rules and regulations  relating to the Plan; to provide
     for conditions and assurances  deemed necessary or advisable to protect the
     interests of the Company  with  respect to the Plan;  and to make all other
     determinations  necessary or advisable for the  administration of the Plan.
     Determinations,  interpretations,  or  other  actions  made or taken by the
     Board with respect to the Plan and Options  granted under the Plan shall be
     final and binding and conclusive for all purposes and upon all persons.

          (b) At the discretion of the Board the Plan may be  administered  by a
     Committee of two or more non-employee Directors appointed by the Board (the
     "Committee").  The  members  of the  Committee  may be  Directors  who  are
     eligible to receive  Options under the Plan,  but Options may be granted to
     such  persons  only by  action  of the full  Board and not by action of the
     Committee.  The Committee  shall have full power and authority,  subject to
     the  limitations of the Plan and any  limitations  imposed by the Board, to
     construe,  interpret  and  administer  the Plan and to make  determinations
     which shall be final,  conclusive  and binding upon all persons,  including
     any persons  having any interests in any Options which may be granted under
     the Plan, and, by resolution or resolutions to provide for the creation and
     issuance of any  Option,  to fix the terms upon which and the time or times
     at or within  which,  and the price or  prices at which any  shares  may be
     purchased from the Company upon the exercise of an Option. Such terms, time
     or times  and  price  or  prices  shall,  in every  case,  be set  forth or
     incorporated  by reference in the instrument or  instruments  evidencing an
     Option, and shall be consistent with the provisions of the Plan.

          (c) Where a Committee  has been created by the Board  pursuant to this
     Article  III,  references  in the Plan to  actions to be taken by the Board
     shall be deemed to refer to the Committee as well,  except where limited by
     the Plan or by the Board.

          (d) No member of the Board or the  Committee  shall be liable  for any
     action or determination  made in good faith with respect to the Plan or any
     Option granted under it.

                                   ARTICLE IV
                            STOCK SUBJECT TO THE PLAN
                            -------------------------

         4.1 Number.  The total  number of shares of common stock of the Company
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(the "Stock")  hereby made  available  and reserved for issuance  under the Plan
upon exercise of Options shall be 1,650,000 shares.  Notwithstanding anything to
the contrary  contained in the foregoing,  to the extent that options are issued
under any  Incentive  Stock Option Plan  adopted by the  Company,  the shares of
common stock reserved for issuance  pursuant to Options  granted under this Plan
shall be reduced.  The aggregate  number of shares of Stock  available under the
Plan shall be subject to adjustment as provided in Section 4.3.

<PAGE>

         4.2 Unused Stock. If an Option shall expire or terminate for any reason
             ------------
without having been exercised in full, or if an "immaculate  cashless  exercise"
(as  described in Section  5.4)  results in the issuance of a reduced  number of
shares in  satisfaction  of an option  grant,  the  unpurchased  shares of Stock
subject thereto shall (unless the Plan shall have  terminated)  become available
for other Options under the Plan.

         4.3 Adjustment  in  Capitalization.  In  the event of any change in the
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outstanding  shares of Stock of the  Company  by reason of a stock  dividend  or
split, recapitalization,  reclassification, or other similar capital change, the
aggregate  number  of  shares  of  Stock  set  forth  in  Section  4.1  shall be
appropriately adjusted by the Board, whose determination shall be conclusive. In
any such case,  the  number and kind of shares of Stock that are  subject to any
Option and the Option price per share shall be proportionately and appropriately
adjusted  without any change in the  aggregate  Option price to be paid therefor
upon exercise of the Option.

                                    ARTICLE V
                             TERMS OF STOCK OPTIONS
                             ----------------------

         5.1 Grant of Options. Subject to Section 4.1, Options may be granted to
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current  and  former  employees,  consultants  and  members  of the Board of the
Company and of any  subsidiary  of the Company at any time and from time to time
as  determined  by the  Board.  The Board  shall  have  complete  discretion  in
determining  the terms and  conditions  and  number of  Options  granted to each
Optionee.  In making such  determinations,  the Board may take into  account the
nature of services  rendered by such current and former  employees,  consultants
and members of the Board,  their  present  and  potential  contributions  to the
Company  and such  other  factors  as the  Board in its  discretion  shall  deem
relevant.

         5.2 Option  Agreement;  Terms and Conditions to Apply Unless  Otherwise
             -------------------------------------------------------------------
Specified. As determined by the Board on the date of grant, each Option shall be
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evidenced by an option agreement (the "Option  Agreement")  that specifies:  the
Option price; the duration of the Option; the number of shares of Stock to which
the Option applies; such vesting or exercisability  restrictions which the Board
may impose;  and any other terms or conditions  which the Board may impose.  All
such terms and conditions  shall be determined by the Board at the time of grant
of the Option.

          (a) If not otherwise  specified by the Board,  the following terms and
     conditions shall apply to Options granted under the Plan:

               (i)   Term.The duration of the Option shall be for ten years from
                     ----
          the date of grant.

               (ii)  Exercise  of  Option.  Unless an Option  is  terminated  as
                     --------------------
          provided  hereunder,  an Optionee may exercise an Option pursuant to a
          vesting and exercisability  schedule as determined by the Board, which
          vesting and  exercisability  schedule shall provide that (A) an Option
          held by an Optionee who retires from employment with the Company after
          having both reached the age of sixty and

<PAGE>


          completed  twelve years of service with the Company shall  continue to
          vest  in  accordance  with  the  vesting  schedule  set  forth  in the
          applicable  Option  Agreement  notwithstanding  the termination of the
          Optionee's  employment  with the Company,  provided  that prior to the
          exercise of the Option such  Optionee  does not after such  retirement
          become  employed on a full-time  basis by a competitor  of the Company
          prior  to  reaching  age  sixty-five,  and  (B) an  Option  held  by a
          non-employee  Director of the Company who retires from the Board after
          completing  at least five years of service to the Company shall become
          fully vested.

               (iii) Termination. Each Option granted pursuant to the Plan shall
                     -----------
          expire upon the earliest to occur of:

                    (A) The date set forth in such  Option,  not to  exceed  ten
               years from the date of grant;

                    (B) The  completion  of the merger or sale of  substantially
               all of the  Stock or  assets of the  Company  with or to  another
               company  in a  transaction  in  which  the  Company  is  not  the
               survivor,   except  for  the  merger  of  the   Company   into  a
               wholly-owned  subsidiary (and the Company shall not be considered
               the surviving  corporation  for purposes hereof if the Company is
               the survivor of a reverse triangular  merger),  provided that the
               Company shall have given the Optionee at least thirty days' prior
               written  notice of its intent to enter into such  merger or sale;
               or

                    (C) The  termination  of the  employment  of an Optionee for
               cause by the Company.

               (iv)  Acceleration.  An Option  shall  become  fully  vested  and
                     ------------
          exercisable irrespective of its other provisions (A) immediately prior
          to the  completion of the merger or sale of  substantially  all of the
          stock or assets of the Company in a  transaction  in which the Company
          is not the  survivor,  except  for the  merger of the  Company  into a
          wholly-owned  subsidiary  (and the Company shall not be considered the
          surviving  corporation  for  purposes  hereof  if the  Company  is the
          survivor of a reverse triangular merger);  (B) upon termination of the
          Optionee's employment with the Company or a subsidiary thereof because
          of death,  disability  or normal  retirement  upon reaching the age of
          sixty-five;  or (C) in the event that the  Optionee is a  non-employee
          member of the Company's  Board of Directors,  upon retirement from the
          Company's Board of Directors after reaching the age of seventy.

               (v)   Transferability.In addition to the Optionee, the Option may
                     ---------------
          be exercised, to the extent exercisable by the Optionee, by the person
          or persons to whom the Optionee's rights under the Option pass by will
          or  the  laws  of  descent  and  distribution,  by the  spouse  or the
          descendants of the Optionee or by trusts for such persons,  to whom or
          which  the  Optionee  may have  transferred  the  Option,  or by legal
          representative  of any of the  foregoing.  Any such transfer  shall be
          made only in

<PAGE>

          compliance  with the  Securities  Act of  1933,  as  amended,  and the
          requirements therefor as set forth by the Company.

                    (b) The Board shall be free to specify terms and  conditions
               other  than and in  addition  to those  set forth  above,  in its
               discretion.

                    (c) All Option  Agreements shall  incorporate the provisions
               of the Plan by reference.

         5.3 Option Price. No Option granted  pursuant to the Plan shall have an
             ------------
Option  price that is less than the fair  market  value of Stock on the date the
Option is granted,  as determined by the Board.  The Option exercise price shall
be subject to adjustment as provided in Section 4.3 above.

         5.4 Payment.  Payment for all shares of Stock shall be made at the time
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that an Option, or any part thereof, is exercised, and no shares shall be issued
until full payment therefor has been made. Payment shall be made (i) in cash, or
(ii) if  acceptable  to the Board,  in Stock,  by the surrender of Option rights
hereunder valued at the difference between the Option exercise price plus income
taxes to be  withheld,  if any,  and the fair market  value of the common  stock
(referred to as "immaculate cashless exercise"), or in some other form.

                                   ARTICLE VI
                        WRITTEN NOTICE, ISSUANCE OF STOCK
                      CERTIFICATES, SHAREHOLDER PRIVILEGES
                      ------------------------------------

         6.1 Written  Notice.  An Optionee  wishing to exercise an Option  shall
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give written  notice to the Company,  in the form and manner  prescribed  by the
Board. Full payment for the shares of Stock acquired pursuant to the Option must
accompany the written notice.

         6.2 Issuance of Stock Certificates. As soon as  practicable  after  the
             ------------------------------
receipt of written notice and payment, the Company shall deliver to the Optionee
a certificate or certificates for the requisite number of shares of Stock.

         6.3 Privileges  of a  Shareholder.  An  Optionee  or  any other  person
             -----------------------------
entitled  to  exercise  an Option  under  the  Option  Agreement  shall not have
shareholder privileges with respect to any Stock covered by the Option until the
date of issuance of a stock certificate for such Stock.

                                   ARTICLE VII
                               RIGHTS OF OPTIONEES
                               -------------------

         Nothing in the Plan shall  interfere with or limit in any way the right
of the Company or a  subsidiary  corporation  to  terminate  any  employee's  or
consultant's  employment at any time, nor confer upon any employee or consultant
any right to continue in the employ of the Company or a subsidiary corporation.

<PAGE>

                                  ARTICLE VIII
                          AMENDMENT, MODIFICATION, AND
                             TERMINATION OF THE PLAN
                             -----------------------

         The Board may at any time  terminate and from time to time may amend or
modify the Plan. Any amendment or  modification  of the Plan by the Board may be
accomplished without approval of the shareholders of the Company,  except in the
event that shareholder approval of such amendment or modification is required by
any law or regulation governing the Company.

        No amendment,  modification,  or  termination  of the Plan shall in any
manner  adversely  affect any  outstanding  Option  under the Plan  without  the
consent of the Optionee holding the Option.

<PAGE>


                                   ARTICLE IX
                       ACQUISITION, MERGER OR LIQUIDATION
                       ----------------------------------

         9.1 Acquisition.
             -----------

                  (a) In the event that an  acquisition  occurs with  respect to
         the Company, the Company shall have the option, but not the obligation,
         to  cancel  Options  outstanding  as of  the  effective  date  of  such
         acquisition,  whether  or not such  Options  are then  exercisable,  in
         return for payment to the  Optionees of an amount equal to a reasonable
         estimate of an amount  (hereinafter  the  "Spread"),  determined by the
         Board, equal to the difference between the net amount per share payable
         in the acquisition or as a result of the acquisition, less the exercise
         price of the Option. In estimating the Spread,  appropriate adjustments
         to give effect to the existence of the Options  shall be made,  such as
         deeming the Options to have been exercised,  with the Company receiving
         the  exercise  price  payable   thereunder,   and  treating  the  Stock
         receivable  upon  exercise  of the  Options  as  being  outstanding  in
         determining the net amount per share.

                  (b) For purposes of this section,  an "acquisition" shall mean
         any transaction in which  substantially all of the Company's assets are
         acquired or in which a controlling amount of the Company's  outstanding
         shares are  acquired,  in each case by a single  person or entity or an
         affiliated group of persons and entities. For purposes of this section,
         a  controlling  amount shall mean more than fifty percent of the issued
         and outstanding shares of Stock of the Company.  The Company shall have
         the above option to cancel Options regardless of how the acquisition is
         effectuated,  whether by direct  purchase,  through a merger or similar
         corporate  transaction,  or otherwise.  In cases where the  acquisition
         consists of the  acquisition  of assets of the Company,  the net amount
         per share shall be calculated on the basis of the net amount receivable
         with  respect to shares  upon a  distribution  and  liquidation  by the
         Company after giving effect to expenses and charges,  including but not
         limited to taxes,  payable by the Company before the liquidation can be
         completed.

                  (c) Where the Company  does not exercise its option under this
         Section 9.1 the remaining provisions of this Article IX shall apply, to
         the extent applicable.

         9.2 Merger or  Consolidation.  If the  Company  shall be the  surviving
             ------------------------
corporation in any merger or  consolidation,  any Option granted hereunder shall
pertain to and apply to the securities to which a holder of the number of shares
of Stock  subject  to the  Option  would have been  entitled  in such  merger or
consolidation,  provided that the Company shall not be considered  the surviving
corporation  for  purposes  hereof if the  Company is the  survivor of a reverse
triangular merger.

         9.3 Other  Transactions.  A dissolution or a liquidation of the Company
             -------------------
or a  merger  and  consolidation  in  which  the  Company  is not the  surviving
corporation  (the Company shall not be considered the surviving  corporation for
purposes hereof if the Company is the survivor of a reverse  triangular  merger)
shall cause every Option outstanding  hereunder to terminate as of the effective
date of such dissolution,  liquidation,  merger or

<PAGE>

consolidation.  However,  the  Optionee  either  (i)  shall  be  offered  a firm
commitment  whereby  the  resulting  or  surviving  corporation  in a merger  or
consolidation will tender to the Optionee an option (the "Substitute Option") to
purchase  its  shares on terms and  conditions  both as to number of shares  and
otherwise,  which will  substantially  preserve to the  Optionee  the rights and
benefits of the Option  outstanding  hereunder  granted by the Company,  or (ii)
shall have the right immediately prior to such dissolution, liquidation, merger,
or consolidation to exercise any unexercised Options whether or not then vested,
subject to the other  provisions of the Plan.  The Board shall have absolute and
uncontrolled  discretion  to  determine  whether the Optionee has been offered a
firm commitment and whether the tendered  Substitute  Option will  substantially
preserve  to the  Optionee  the rights and  benefits  of the Option  outstanding
hereunder.

                                    ARTICLE X
                             SECURITIES REGISTRATION
                             -----------------------

         10.1 Securities Registration.  In the event that the Company shall deem
              -----------------------
it  necessary  or desirable to register  under the  Securities  Act of 1933,  as
amended, or any other applicable statute,  any Options or any Stock with respect
to which an Option may be or shall have been granted or exercised, or to qualify
any such Options or Stock under the Securities  Act of 1933, as amended,  or any
other statute,  then the Optionee shall cooperate with the Company and take such
action as is necessary to permit  registration or  qualification of such Options
or Stock.

         10.2 Representations.  Unless  the  Company  has  determined  that  the
              ---------------
following representation is unnecessary,  each person exercising an Option under
the Plan may be required by the  Company,  as a condition to the issuance of the
shares of Stock pursuant to exercise of the Option,  to make a representation in
writing (i) that he is acquiring  such shares for his own account for investment
and not with a view to, or for sale in connection  with, the distribution of any
part thereof  within the meaning of the  Securities  Act of 1933,  and (ii) that
before any transfer in connection with the resale of such shares, he will obtain
the written opinion of counsel for the Company,  or other counsel  acceptable to
the Company,  that such shares may be transferred without registration  thereof.
The Company may also  require  that the  certificates  representing  such shares
contain  legends  reflecting  the  foregoing.  To the extent  permitted  by law,
including the Securities Act of 1933, nothing herein shall restrict the right of
a person  exercising  an Option to sell the shares  received  in an open  market
transaction.

                                   ARTICLE XI
                                 TAX WITHHOLDING
                                 ---------------

        Whenever  shares of Stock are to be issued in  satisfaction  of Options
exercised  under the Plan,  the  Company  shall  have the power to  require  the
recipient of the Stock to remit to the Company an amount  sufficient  to satisfy
federal, state, and local withholding tax requirements, if any.

<PAGE>

                                   ARTICLE XII
                                 INDEMNIFICATION
                                 ---------------

         To the extent permitted by law, each person who is or shall have been a
member of the Board or the Committee  shall be indemnified  and held harmless by
the Company against and from any loss, cost,  liability,  or expense that may be
imposed upon or reasonably  incurred by him in connection with or resulting from
any claim, action, suit, or proceeding to which he may be a party or in which he
may be involved  by reason of any action  taken or failure to act under the Plan
and against and from any and all amounts paid by him in settlement thereof, with
the Company's  approval,  or paid by him in satisfaction of judgment in any such
action,  suit, or proceeding  against him, provided he shall give the Company an
opportunity,  at its own  expense,  to  handle  and  defend  the same  before he
undertakes  to handle and defend it on his own behalf.  The  foregoing  right of
indemnification shall not be exclusive of any other rights of indemnification to
which  such  persons  may  be  entitled  under  the  Company's   certificate  of
incorporation or bylaws, as a matter of law, or otherwise, or any power that the
Company or a  Subsidiary  Corporation  may have to  indemnify  them or hold them
harmless.

                                  ARTICLE XIII
                               REQUIREMENTS OF LAW
                               -------------------

         13.1 Requirements  of Law. The granting  of Options and the issuance of
              --------------------
shares  of  Stock  upon the  exercise  of an  Option  shall  be  subject  to all
applicable  laws,  rules,  and  regulations,   and  to  such  approvals  by  any
governmental agencies or national securities exchanges as may be required.

          13.2 Governing Law. The Plan, and all agreements  hereunder,  shall be
               -------------
construed in accordance with and governed by the laws of the  State of Colorado.

                                   ARTICLE XIV
                             EFFECTIVE DATE OF PLAN
                             ----------------------

         The Plan shall be effective on November 21, 1996.

                                   ARTICLE XV
                        NO OBLIGATION TO EXERCISE OPTION
                        --------------------------------

         The granting of an Option shall  impose no  obligation  upon the holder
thereof to exercise such Option.


<PAGE>

         THIS STOCK  OPTION  PLAN was adopted by the Board of  Directors  of St.
Mary Land &  Exploration  Company on November  21, 1996,  to be  effective  upon
adoption,  and was amended by the Board of  Directors  on January 31,  1997,  on
March 25, 1999 to increase the number of shares  available  for  issuance  under
Article IV to 1,650,000, and on January 27, 2000.

                         ST. MARY LAND & EXPLORATION COMPANY

                         By:     /s/ RICHARD C. NORRIS
                                 ---------------------
                                 Richard C. Norris

                         Title:  Vice President-Finance, Secretary and Treasurer


