
<PAGE>
                                    FORM OF
                          SUPPLEMENTAL TRUST INDENTURE
                                      FROM
                         NORTHERN STATES POWER COMPANY

                                       TO
                         HARRIS TRUST AND SAVINGS BANK
                                    TRUSTEE
                                 --------------
                             DATED
                                 --------------
                        SUPPLEMENTAL TO TRUST INDENTURE
                             DATED FEBRUARY 1, 1937
                                      AND
                           SUPPLEMENTAL AND RESTATED
                             TRUST INDENTURE DATED
                                  MAY 1, 1988
<PAGE>
                               TABLE OF CONTENTS
                                 --------------

<TABLE>
<CAPTION>
                                                                                                                PAGE
                                                                                                                -----
<S>                   <C>                                                                                    <C>
Parties....................................................................................................           1

Recitals...................................................................................................           1

Form of Bonds of Series Due                ................................................................           2

Form of Trustee's Certificate..............................................................................           5

Further Recitals...........................................................................................           5

                                                       ARTICLE I.
                               SPECIFIC SUBJECTION OF ADDITIONAL PROPERTY TO THE LIEN OF
                                                THE ORIGINAL INDENTURE.
Section 1.01--        Grant of certain property, including personal property to comply with the Uniform
                      Commercial Code, subject to permitted liens and other exceptions contained in 1937
                      Indenture............................................................................           6

                                                      ARTICLE II.
                              FORM AND EXECUTION OF BONDS OF SERIES DUE                 .

Section 2.01--        Terms of bonds.......................................................................           7

Section 2.02--        Redemption of bonds..................................................................           8

Section 2.03--        Interchangeability of bonds..........................................................           8

Section 2.04--        Charges for exchange or transfer of bonds............................................           9

Section 2.05--        Execution of bonds...................................................................           9

Section 2.06--        Book-Entry System....................................................................           9

                                                      ARTICLE III.
                       [NOTE: PROVISIONS RELATING TO A SINKING FUND WILL BE OMITTED IF A SINKING
                               FUND IS NOT ESTABLISHED FOR A PARTICULAR SERIES OF BONDS]
                                                     SINKING FUND.

Section 3.01--(a)     Sinking Fund established for bonds of Series due                 ....................          11

            (b)       Bonds delivered to Trustee equivalent to cash under Section 3.01(a)..................          12

            (c)       Permanent additions to the extent available as basis for issuance of bonds,
                      equivalent to cash under Section 3.01(a).............................................          12

Section 3.02--(a)     Moneys to be applied to purchase or redemption of bonds of Series due
                                      .....................................................................          12

            (b)       Bonds to be selected by lot..........................................................          13

            (c)       Effect of deposit of moneys for redemption...........................................          13

            (d)       Exchange of registered bonds for unredeemed balance of registered bonds..............          13

Section 3.03--        Bonds purchased or redeemed to be cancelled..........................................          13

                                                      ARTICLE IV.
                                          APPOINTMENT OF AUTHENTICATING AGENT.

Section 4.01--        Appointment of agent or agents for bonds of Series due                ...............          13
</TABLE>
<PAGE>

                                       ii

<TABLE>
<CAPTION>
                                                                                                                PAGE
                                                                                                                -----
<S>                   <C>                                                                                    <C>
Section 4.02--(a)     Qualification of agents..............................................................          13

            (b)       Continuation of agent upon merger or consolidation...................................          13

            (c)       Termination of successor agent.......................................................          14

            (d)       Compensation of agent................................................................          14

Section 4.03--        Form of alternate certificate of authentication......................................          14

Section 4.04--        Limit on location and number of agents...............................................          14

                                                       ARTICLE V.
                                         FINANCING STATEMENT TO COMPLY WITH THE
                                                UNIFORM COMMERCIAL CODE.

Section 5.01--        Names and addresses of debtor and secured party......................................          15

Section 5.02--        Property subject to lien.............................................................          15

Section 5.03--        Maturity dates and principal amounts of obligations secured..........................          15

Section 5.04--        Financing Statement adopted for all First Mortgage Bonds listed in Section 5.03......          15

Section 5.05--        Recording data for the 1937 Indenture and prior Supplemental Trust Indentures........          15

Section 5.06--        Financing Statement covers additional series of First Mortgage Bonds.................          16

                                                      ARTICLE VI.
                                                AMENDMENTS TO INDENTURE.

Section 6.01--        Consent of holders of Bonds..........................................................          17

                                                      ARTICLE VII.
                                                     MISCELLANEOUS.

Section 7.01--        Recitals of fact, except as stated, are statements of the Company....................          17

Section 7.02--        Supplemental Trust Indenture to be construed as a part of the 1937 Indenture, as
                      supplemented.........................................................................          17

Section 7.03--(a)     Trust Indenture Act to control.......................................................          17

            (b)       Severability of conditions contained in Supplemental Trust Indenture and bonds.......          17

Section 7.04--        Word "Indenture" as used herein includes in its meaning the 1937 Indenture and all
                      indentures supplemental thereto......................................................          17

Section 7.05--        References to either party in Supplemental Trust Indenture include successors or
                      assigns..............................................................................          17

Section 7.06--(a)     Provision for execution in counterparts..............................................          18

            (b)       Table of Contents and descriptive headings of Articles not to affect meaning.........          18
                                                     --------------

Schedule A.................................................................................................         A-1
</TABLE>
<PAGE>
    Supplemental  Trust Indenture, made as of  the  st day of           , by and
between NORTHERN STATES POWER COMPANY, a corporation duly organized and existing
under and by virtue of the laws of the State of Minnesota, having its  principal
office  in the City of  Minneapolis in said State  (the "Company"), party of the
first part, and HARRIS TRUST AND SAVINGS BANK, a corporation duly organized  and
existing  under and by virtue  of the laws of the  State of Illinois, having its
principal office  in  the  City  of  Chicago in  said  State,  as  Trustee  (the
"Trustee"), party of the second part;

WITNESSETH:

    WHEREAS,  the Company heretofore  has executed and  delivered to the Trustee
its Trust Indenture (the "1937 Indenture"), made as of February 1, 1937, whereby
the Company granted, bargained,  sold, warranted, released, conveyed,  assigned,
transferred,  mortgaged, pledged, set over, and confirmed to the Trustee, and to
its respective successors in trust, all property, real, personal, and mixed then
owned or thereafter acquired or to be acquired by the Company (except as therein
excepted from  the lien  thereof) and  subject  to the  rights reserved  by  the
Company  in and  by the  provisions of the  1937 Indenture,  to be  held by said
Trustee in trust  in accordance with  provisions of the  1937 Indenture for  the
equal  pro  rata benefit  and  security of  all and  every  of the  bonds issued
thereunder in accordance with the provisions thereof; and

    WHEREAS, the Company heretofore has executed and delivered to the Trustee  a
Supplemental  Trust  Indenture, made  as of  June 1,  1942, whereby  the Company
conveyed, assigned, transferred, mortgaged, pledged, set over, and confirmed  to
the  Trustee, and its  respective successors in  said trust, additional property
acquired by it subsequent to the date of the 1937 Indenture; and

    WHEREAS, the Company heretofore  has executed and  delivered to the  Trustee
the  following additional  Supplemental Trust  Indentures which,  in addition to
conveying, assigning,  transferring,  mortgaging, pledging,  setting  over,  and
confirming  to  the  Trustee,  and  its  respective  successors  in  said trust,
additional property acquired  by it subsequent  to the preparation  of the  next
preceding  Supplemental Trust Indenture and adding to the covenants, conditions,
and agreements of the 1937  Indenture certain additional covenants,  conditions,
and  agreements to be observed  by the Company, created  the following series of
First Mortgage Bonds:

<TABLE>
<CAPTION>
     DATE OF SUPPLEMENTAL
       TRUST INDENTURE                            DESIGNATION OF SERIES
- ------------------------------  ----------------------------------------------------------
<S>                             <C>
February 1, 1944                Series due February 1, 1974 (retired)
October 1, 1945                 Series due October 1, 1975 (retired)
July 1, 1948                    Series due July 1, 1978 (retired)
August 1, 1949                  Series due August 1, 1979 (retired)
June 1, 1952                    Series due June 1, 1982 (retired)
October 1, 1954                 Series due October 1, 1984 (retired)
September 1, 1956               Series due 1986 (retired)
August 1, 1957                  Series due August 1, 1987 (redeemed)
July 1, 1958                    Series due July 1, 1988 (retired)
December 1, 1960                Series due December 1, 1990 (retired)
August 1, 1961                  Series due August 1, 1991 (retired)
June 1, 1962                    Series due June 1, 1992 (retired)
September 1, 1963               Series due September 1, 1993 (retired)
August 1, 1966                  Series due August 1, 1996 (redeemed)
June 1, 1967                    Series due June 1, 1995 (redeemed)
October 1, 1967                 Series due October 1, 1997 (redeemed)
May 1, 1968                     Series due May 1, 1998 (redeemed)
October 1, 1969                 Series due October 1, 1999 (redeemed)
February 1, 1971                Series due March 1, 2001 (redeemed)
May 1, 1971                     Series due June 1, 2001 (redeemed)
February 1, 1972                Series due March 1, 2002
January 1, 1973                 Series due February 1, 2003
January 1, 1974                 Series due January 1, 2004 (redeemed)
September 1, 1974               Pollution Control Series A (redeemed)
April 1, 1975                   Pollution Control Series B (redeemed)
May 1, 1975                     Series due May 1, 2005 (redeemed)
March 1, 1976                   Pollution Control Series C
</TABLE>
<PAGE>

                                       2

<TABLE>
<CAPTION>
     DATE OF SUPPLEMENTAL
       TRUST INDENTURE                            DESIGNATION OF SERIES
- ------------------------------  ----------------------------------------------------------
<S>                             <C>
June 1, 1981                    Pollution Control Series D, E and F (redeemed)
December 1, 1981                Series due December 1, 2011 (redeemed)
May 1, 1983                     Series due May 1, 2013 (redeemed)
December 1, 1983                Pollution Control Series G (redeemed)
September 1, 1984               Pollution Control Series H (redeemed)
December 1, 1984                Resource Recovery Series I
May 1, 1985                     Series due June 1, 2015 (redeemed)
September 1, 1985               Pollution Control Series J, K and L
July 1, 1989                    Series due July 1, 2019 (redeemed)
June 1, 1990                    Series due June 1, 2020 (redeemed)
October 1, 1992                 Series due October 1, 1997
April 1, 1993                   Series due April 1, 2003
December 1, 1993                Series due December 1, 2000, and December 1, 2005
February 1, 1994                Series due February 1, 1999
October 1, 1994                 Series due October 1, 2001
June 1, 1995                    Series due July 1, 2025
                                                  ; and
</TABLE>

    WHEREAS, the  1937 Indenture  and all  of the  foregoing Supplemental  Trust
Indentures are referred to herein collectively as the "Original Indenture;" and

    WHEREAS,  the Company heretofore has executed and delivered to the Trustee a
Supplemental and  Restated Trust  Indenture, dated  May 1,  1988 (the  "Restated
Indenture"),   which,  in   addition  to   conveying,  assigning,  transferring,
mortgaging, pledging,  setting over,  and  confirming to  the Trustee,  and  its
respective  successors  in  said  trust,  additional  property  acquired  by  it
subsequent  to  the  preparation  of  the  next  preceding  Supplemental   Trust
Indenture, amended and restated the Original Indenture; and

    WHEREAS,  the  Restated Indenture  will not  become effective  and operative
until all bonds of each series issued under the Original Indenture prior to  May
1,  1988 shall have been retired  through payment or redemption (including those
bonds "deemed to be  paid" within the  meaning of that term  as used in  Article
XVII of the 1937 Indenture) or until, subject to certain exceptions, the holders
of  the requisite  principal amount  of such bonds  shall have  consented to the
amendments contained in the  Restated Indenture (such  date being herein  called
the "Effective Date"); and

    WHEREAS,  the Original Indenture and the  Restated Indenture are referred to
herein collectively as the "Indenture"; and

    WHEREAS, the Indenture provides that bonds  may be issued thereunder in  one
or more series, each series to have such distinctive designation as the Board of
Directors of the Company may select for such series; and

    WHEREAS,  the Company  is desirous  of providing for  the creation  of a new
series of First Mortgage Bonds, said new series of bonds to be designated "First
Mortgage Bonds, Series due           ," the bonds of said series to be issued as
registered bonds without coupons  in denominations of a  multiple of $1000,  and
the  bonds of  said series  to be  substantially in  the form  and of  the tenor
following [with the redemption  prices inserted therein  in conformity with  the
provisions of Section 2.02 hereof,], to-wit:

                    (Form of Bonds of Series due           )
                         NORTHERN STATES POWER COMPANY
            (Incorporated under the laws of the State of Minnesota)
                              First Mortgage Bond
                             Series due
No. ______________                                              $ ______________
<PAGE>
                                       3

    [Unless this certificate is presented by an authorized representative of The
Depository Trust Company, a New York corporation, to the issuer or its agent for
registration  of transfer,  exchange or payment,  and any  certificate issued is
registered in the  name of  Cede & Co.  or such  other name as  requested by  an
authorized  representative of The  Depository Trust Company  (and any payment is
made to Cede  & Co. or  to such other  entity as is  requested by an  authorized
representative  of The Depository Trust Company),  ANY TRANSFER, PLEDGE OR OTHER
USE HEREOF FOR  VALUE OR OTHERWISE  BY OR TO  ANY PERSON IS  WRONGFUL since  the
registered owner hereof, Cede & Co., has an interest herein.]*

    NORTHERN  STATES POWER COMPANY,  a corporation organized  and existing under
the laws of the State of  Minnesota (the "Company"), for value received,  hereby
promises  to pay to                 or  registered assigns, at the office of the
Trustee, in Chicago, Illinois, or, at the option of the registered owner, at the
agency of the Company in the Borough  of Manhattan, City and State of New  York,
the  sum of                    Dollars in  lawful money of  the United States of
America, on the     day of          , and  to pay interest hereon from the  date
hereof  at the rate of                   percent per annum, in like money, until
the Company's obligation with respect to the payment of such principal sum shall
be discharged; said interest being payable at the option of the person  entitled
to  such interest either at the office  of the Trustee, in Chicago, Illinois, or
at the agency of the Company in the Borough of Manhattan, City and State of  New
York,  on the    day of       and on the    day of    in each year provided that
as long as there is  no existing default in the  payment of interest and  except
for  the payment of defaulted interest, the  interest payable on any          or
     will be paid to the  person in whose name this  bond was registered at  the
close  of business on the record date (the             prior to  such         or
the        prior to such        unless any such date is  not a business day,  in
which event it will be the next preceding business day).

    ["EXCEPT  UNDER THE LIMITED CIRCUMSTANCES  DESCRIBED IN THE INDENTURE, THESE
GLOBAL BONDS MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITORY OR BY  A
NOMINEE  OF THE DEPOSITORY TO THE DEPOSITORY, ANOTHER NOMINEE OF THE DEPOSITORY,
A SUCCESSOR OF THE DEPOSITORY OR A NOMINEE OF SUCH SUCCESSOR."]*

    This bond is one of a duly authorized issue of bonds of the Company, of  the
series  and  designation indicated  on  the face  hereof,  which issue  of bonds
consists, or may consist, of several series of varying denominations, dates, and
tenor, all issued and to be issued under and equally secured (except insofar  as
a  sinking fund, or similar fund,  established in accordance with the provisions
of the Indenture may  afford additional security for  the bonds of any  specific
series)  by a Trust Indenture dated February  1, 1937 (the "1937 Indenture"), as
supplemented by  supplemental trust indentures (collectively, the  "Supplemental
Indentures"), a Supplemental and Restated Trust Indenture dated May 1, 1988 (the
"Restated  Indenture") and a  new supplemental trust indenture  for the bonds of
this series  (the "New  Supplemental  Indenture"), executed  by the  Company  to
Harris  Trust and Savings Bank, as  Trustee (the "Trustee"). The 1937 Indenture,
as supplemented by the Supplemental  Indentures, the Restated Indenture and  the
New   Supplemental  Indenture  herein  are   referred  to  collectively  as  the
"Indenture". Reference hereby is made to the Indenture for a description of  the
property  mortgaged  and pledged,  the nature  and extent  of the  security, the
rights of  the holders  of the  bonds as  to such  security, and  the terms  and
conditions  upon  which the  bonds may  be  issued under  the Indenture  and are
secured. The  principal  hereof  may  be  declared or  may  become  due  on  the
conditions,  in the manner and at the time  set forth in the Indenture, upon the
happening of a default as in the Indenture provided.

    With the  consent of  the Company  and to  the extent  permitted by  and  as
provided  in the Indenture, the rights and obligations of the Company and of the
holders of the bonds, and the terms  and provisions of the Indenture and of  any
instruments  supplemental thereto may be modified or altered by affirmative vote
of the holders of at least 80% in principal amount of the bonds then outstanding
under the Indenture  and any instruments  supplemental thereto (excluding  bonds
challenged  and disqualified  from voting  by reason  of the  Company's interest
therein as provided in the Indenture); provided that without the consent of  all
holders  of all bonds  affected no such modification  or alteration shall permit
the extension of the maturity of the principal of

- ------------------------
*This legend is  to be  included if the  bonds are  issued as a  Global bond  in
book-entry form.
<PAGE>
                                       4

any  bond  or  the  reduction in  the  rate  of interest  thereon  or  any other
modification in  the  terms  of  payment of  such  principal  or  interest.  The
foregoing  80% requirement  will be reduced  to 66  2/3% when all  bonds of each
series issued under the Indenture prior to May 1, 1985, shall have been  retired
or all the holders thereof shall have consented to such reduction.

    The  Restated  Indenture  amends and  restates  the 1937  Indenture  and the
Supplemental Indentures.  The  Restated  Indenture  will  become  effective  and
operative  (the "Effective Date") when all Bonds of each series issued under the
Indenture prior  to May  1, 1988  shall  have been  retired through  payment  or
redemption (including those bonds "deemed to be paid" within the meaning of that
term as used in Article XVII of the 1937 Indenture) or until, subject to certain
exceptions,  the holders of  the requisite principal amount  of such bonds shall
have consented to the amendments contained in the Restated Indenture. Holders of
the bonds of this series and of each subsequent series of bonds issued under the
Indenture likewise will  be bound by  the amendments contained  in the  Restated
Indenture  when they  become effective and  operative. Reference is  made to the
Restated Indenture  for  a  complete description  of  the  amendments  contained
therein to the 1937 Indenture and to the Supplemental Indentures.

    The Company and the Trustee may deem and treat the person in whose name this
bond  is registered as  the absolute owner  hereof for the  purpose of receiving
payment and for all other  purposes and shall not be  affected by any notice  to
the contrary.

    [At  the option of the Company, and upon not less than 30 days' notice prior
to the date fixed for redemption, in the manner and with the effect provided  in
the  Indenture, any or all of the  bonds of this Series due             , may be
redeemed, other than for the Sinking Fund provided for bonds of this series,  by
the Company on any date by the payment of principal, the accrued interest to the
date of redemption, and the applicable premium on the principal amount specified
in the tabulation below under the heading "Regular Redemption Premium," provided
that no bond of the Series due           , shall be redeemed (other than through
said  Sinking Fund)  prior to               , and  this bond is  entitled to the
benefits of and is subject to call for redemption at par for the Sinking Fund on
December 1 of each year beginning     , upon like  notice and in the manner  and
with  the effect  provided in  the Indenture,  by the  payment of  principal and
accrued interest to the date of redemption:

<TABLE>
<S>                     <C>
  If Redeemed During      Regular
   the Twelve Month     Redemption
        Period            Premium
      Beginning
</TABLE>

- --------------------------------------------------------------------------------

(REDEMPTION PREMIUMS ARE TO BE INSERTED IN EACH BOND IN CONFORMITY WITH SECTION
                                     2.02)

    [Bonds of this series are not redeemable prior to maturity, for any  reason,
and are not subject to a sinking fund.]

    This  bond is transferable as prescribed  in the Indenture by the registered
owner hereof in person, or by his duly authorized attorney, at the office of the
Trustee in Chicago, Illinois, or at the option of the owner at the agency of the
Company in the Borough of Manhattan, City and State of New York, or elsewhere if
authorized by the  Company, upon surrender  and cancellation of  this bond,  and
thereupon  a  new bond  or bonds  of the  same  series and  of a  like aggregate
principal amount  will be  issued  to the  transferee  in exchange  therefor  as
provided  in the Indenture, upon payment of taxes or other governmental charges,
if any, that may be imposed in relation thereto.

    Bonds of this series are interchangeable  as to denominations in the  manner
and upon the conditions prescribed in the Indenture.

    No charge shall be made by the Company for any exchange or transfer of bonds
of  the Series  due               , other  than for taxes  or other governmental
charges, if any, that may be imposed in relation thereto.

    No recourse shall be had for the payment of the principal of or the interest
on this bond, or any  part thereof, or of any  claim based hereon or in  respect
hereof   or  of  said   Indenture,  against  any   incorporator,  or  any  past,
<PAGE>
                                       5

present, or future  shareholder, officer or  director of the  Company or of  any
predecessor or successor corporation, either directly or through the Company, or
through  any such predecessor or successor  corporation, or through any receiver
or a trustee in bankruptcy, whether  by virtue of any constitution, statute,  or
rule of law or by the enforcement of any assessment or penalty or otherwise, all
such  liability being, by the acceptance hereof and as part of the consideration
for the issue hereof, expressly waived  and released, as more fully provided  in
the Indenture.

    This bond shall not be valid or become obligatory for any purpose unless and
until  the certificate of authentication hereon shall  have been signed by or on
behalf of Harris Trust and Savings Bank, as Trustee under the Indenture, or  its
successor thereunder.

    IN WITNESS WHEREOF, NORTHERN STATES POWER COMPANY has caused this bond to be
executed  in its  name by its  President or  a Vice President  and its corporate
seal, or a facsimile thereof, to be hereto affixed and attested by its Secretary
or an Assistant Secretary.
    Dated: ____________________________       NORTHERN STATES POWER COMPANY
        Attest: ________________________  By ___________________________________
         _________ Secretary                       _________ President

                          (Form of Trustee's Certificate)

    This bond is one of the bonds of the Series designated thereon, described in
the within-mentioned Indenture.

                                          HARRIS TRUST AND SAVINGS BANK,
                                                As Trustee,
                                            By _________________________________
                                                      Authorized Officer

and

    WHEREAS, the  Company is  desirous  of conveying,  assigning,  transferring,
mortgaging,  pledging, setting  over, and confirming  to the Trustee  and to its
respective successors in trust, additional property acquired by it subsequent to
the  date  of  the  preparation  of  the  Supplemental  Trust  Indenture   dated
             ; and

    WHEREAS,  the  Indenture  provides in  substance  that the  Company  and the
Trustee may enter into indentures  supplemental thereto for the purposes,  among
others, of creating and setting forth the particulars of any new series of bonds
and  of providing  the terms  and conditions of  the issue  of the  bonds of any
series not expressly provided for in the Indenture and of conveying,  assigning,
transferring,  mortgaging, pledging, setting over, and confirming to the Trustee
additional property of the Company, and  for any other purpose not  inconsistent
with the terms of the Indenture; and

    WHEREAS, the execution and delivery of this Supplemental Trust Indenture has
been  duly authorized by a  resolution adopted by the  Board of Directors of the
Company; and

    WHEREAS, the Trustee has duly determined to execute this Supplemental  Trust
Indenture  and to be bound, insofar as it  may lawfully do so, by the provisions
hereof;

    Now THEREFORE,  Northern  States  Power Company,  in  consideration  of  the
premises  and of  one dollar duly  paid to  it by the  Trustee at  or before the
ensealing and  delivery  of these  presents,  the  receipt of  which  is  hereby
acknowledged,  and other good and  valuable considerations, does hereby covenant
and agree  to and  with  Harris Trust  and Savings  Bank,  as Trustee,  and  its
successors in the trust under the Indenture for the benefit of those who hold or
shall  hold the  bonds, or  any of them,  issued or  to be  issued thereunder as
follows:
<PAGE>
                                       6

                                   ARTICLE I.
                 SPECIFIC SUBJECTION OF ADDITIONAL PROPERTY TO
                      THE LIEN OF THE ORIGINAL INDENTURE.

    SECTION 1.01. The Company in order to better secure the payment, of both the
principal and interest,  of all  bonds of the  Company at  any time  outstanding
under  the Indenture according to their tenor  and effect and the performance of
and compliance with the covenants and conditions contained in the Indenture, has
granted, bargained, sold, warranted, released, conveyed, assigned,  transferred,
mortgaged,  pledged, set over,  and confirmed and by  these presents does grant,
bargain, sell, warrant, release, convey, assign, transfer, mortgage, pledge, set
over, and confirm to the Trustee and to its respective successors in said  trust
forever,  subject to the rights reserved by the Company in and by the provisions
of the Indenture, all of the property described and mentioned or enumerated in a
schedule annexed hereto and marked Schedule A, reference to said schedule  being
made  hereby with  the same force  and effect  as if the  same were incorporated
herein at length; together with  all and singular the tenements,  hereditaments,
and  appurtenances  belonging  and  in any  way  appertaining  to  the aforesaid
property or any part  thereof with the reversion  and reversions, remainder  and
remainders,  tolls, rents  and revenues,  issues, income,  products, and profits
thereof;

    Also, in order to subject the personal property and chattels of the  Company
to  the lien of the Indenture and to  conform with the provisions of the Uniform
Commercial Code,  all  fossil, nuclear,  hydro,  and other  electric  generating
plants,   including  buildings  and   other  structures,  turbines,  generators,
exciters,  boilers,  reactors,  nuclear  fuel,  other  boiler  plant  equipment,
condensing  equipment and all other  generating equipment; substations; electric
transmission and  distribution  systems, including  structures,  poles,  towers,
fixtures,  conduits,  insulators,  wires,  cables,  transformers,  services  and
meters; steam heating  mains and  equipment; gas  transmission and  distribution
systems,  including structures, storage  facilities, mains, compressor stations,
purifier stations, pressure holders, governors, services, and meters;  telephone
plant  and related distribution systems; trucks  and trailers; office, shop, and
other buildings and structures, furniture and equipment; apparatus and equipment
of all other kinds and descriptions;  materials and supplies; all municipal  and
other  franchises, leaseholds, licenses, permits, privileges, patents and patent
rights; all  shares  of  stock, bonds,  evidences  of  indebtedness,  contracts,
claims,  accounts receivable, choses in action  and other intangibles, all books
of account and other corporate records;

    Excluding, however, all merchandise  and appliances heretofore or  hereafter
acquired for the purpose of sale to customers and others;

    All  the estate,  right, title, interest,  and claim, whatsoever,  at law as
well as in equity, which the Company now has or hereafter may acquire in and  to
the  aforesaid property and  every part and parcel  thereof subject, however, to
the right of the Company, until the happening of a completed default as  defined
in  Section 1 of Article  XIII of the Original  Indenture prior to the Effective
Date and upon the occurrence and continuation of a Completed Default as  defined
in  the Indenture on and  after the Effective Date,  to retain in its possession
all shares of stock, notes, evidences of indebtedness, other securities and cash
not expressly  required  by the  provisions  hereof  to be  deposited  with  the
Trustee,  to  retain  in  its  possession  all  contracts,  bills  and  accounts
receivable, motor cars, any stock of goods, wares and merchandise, equipment  or
supplies acquired for the purpose of consumption in the operation, construction,
or  repair  of any  of the  properties of  the Company,  and to  sell, exchange,
pledge, hypothecate, or  otherwise dispose  of any or  all of  such property  so
retained  in  its  possession  free  from the  lien  of  the  Indenture, without
permission or hindrance on the part of  the Trustee, or any of the  bondholders.
No person in any dealings with the Company in respect of any such property shall
be  charged with any notice or knowledge of any such completed default (prior to
the Effective Date) or  Completed Default (after the  Effective Date) under  the
Indenture while the Company is in possession of such property. Nothing contained
herein  or in the Indenture shall be  deemed or construed to require the deposit
with, or delivery to,  the Trustee of  any of such property,  except such as  is
specifically required to be deposited with the Trustee by some express provision
of the Indenture;
<PAGE>
                                       7

    To  have and to hold all said  property, real, personal, and mixed, granted,
bargained,  sold,   warranted,   released,  conveyed,   assigned,   transferred,
mortgaged,  pledged,  set over,  or confirmed  by the  Company as  aforesaid, or
intended so  to be,  to the  Trustee  and its  successors and  assigns  forever,
subject, however, to permitted liens as defined in Section 5 of Article I of the
1937  Indenture prior to the Effective Date and to Permitted Encumbrances on and
after the Effective Date and to the further reservations, covenants, conditions,
uses, and trusts set forth in the Indenture; in trust nevertheless for the  same
purposes and upon the same conditions as are set forth in the Indenture.

                                  ARTICLE II.
              FORM AND EXECUTION OF BONDS OF SERIES DUE

    SECTION  2.01. There hereby is created,  for issuance under the Indenture, a
series of bonds designated Series due            , each of which shall bear  the
descriptive  title "First Mortgage Bond,  Series due              , and the form
thereof shall contain suitable provisions with respect to the matters  hereafter
specified  in this Section. The  bonds of said series  shall be substantially of
the tenor  and purport  hereinbefore recited.  The bonds  of said  series  shall
mature             , and shall be  issued as registered bonds without coupons in
denominations of  a multiple  of $1,000.  The bonds  of said  series shall  bear
interest at the rate of   % per annum payable semi-annually on         and
of each year, and the principal shall be payable at the office of the Trustee in
Chicago, Illinois, or at the option of the registered owner at the agency of the
Company in the Borough of Manhattan, City and State of New York, in lawful money
of the United States of America, and the interest shall be payable in like money
at  the option of the person entitled to  such interest either at said office of
the Trustee in Chicago, Illinois, or at the agency of the Company in the Borough
of Manhattan, City and State of New York.  Bonds of the Series due             ,
shall be dated as of the interest payment date next preceding the authentication
thereof by the Trustee except that (i) if any bond shall be authenticated before
             ,  it shall  be dated as  of               , unless  (iii) below is
applicable, (ii) if the  Company shall at  the time of  the authentication of  a
bond of the Series due           , be in default in the payment of interest upon
the  bonds of the Series due           , such bond shall be dated as of the date
of the beginning of  the period for  which such interest is  so in default,  and
(iii)  as long as there is no existing default in the payment of interest on the
bonds of the Series due            , if any bond of the Series  due            ,
shall  be authenticated after the close of business on any Record Date but on or
prior to the interest  payment date relating  to such Record  Date, it shall  be
dated as of such interest payment date.

    As  long as there is  no existing default in the  payment of interest on the
bonds of the Series due             , the person  in whose name any bond of  the
Series due           , is registered at the close of business on any Record Date
with  respect to  any interest  payment date  shall be  entitled to  receive the
interest payable on such interest  payment date notwithstanding any transfer  or
exchange  of such bond of the  Series due             , subsequent to the Record
Date and on or prior to such interest payment date, except as and to the  extent
the  Company shall default in  the payment of the  interest due on such interest
payment date, in which case such defaulted interest shall be paid to the  person
in whose name such bond of the Series due           , is registered on a Special
Record  Date  for the  payment of  such defaulted  interest to  be fixed  by the
Trustee, notice thereof shall be given to  the registered holder of any bond  of
the  Series due            , not less  than 10 days prior to such Special Record
Date, or may be  paid at any  time in any other  lawful manner not  inconsistent
with  the requirements  of any  securities exchange  on which  the bonds  of the
Series due            may be listed, and upon such notice as may be required  by
such exchange.

    The  term "Record Date" as used herein  with respect to any interest payment
date (         or       ) shall mean the              prior to such           or
      prior  to such      unless such            or      shall not be a business
day, in which event  "Record Date" shall mean  the next preceding business  day.
The  term "business day" as used herein shall mean any day other than a Saturday
or a Sunday or a day on which the offices of the Trustee in the City of Chicago,
Illinois, are closed pursuant to authorization of law.

    As used in this Section 2.01, the term "default in the payment of  interest"
means   failure  to  pay  interest  on  the  applicable  interest  payment  date
disregarding any period of grace permitted by the Indenture.
<PAGE>
                                       8

    The "Special Record  Date" as used  herein shall be  fixed in the  following
manner.  The  Company shall  notify  the Trustee  in  writing of  the  amount of
defaulted interest  proposed  to  be  paid  on  each  bond  of  the  Series  due
          ,  and the  date of  the proposed  payment, and  at the  same time the
Company shall deposit with the Trustee an amount of money equal to the aggregate
amount proposed to be paid in respect  of such defaulted interest or shall  make
arrangements  satisfactory to the Trustee for such  deposit prior to the date of
the proposed payment,  such money when  deposited to  be held in  trust for  the
benefit  of the persons entitled to such  defaulted interest as provided in this
Section 2.01. Thereupon  the Trustee  shall fix a  Special Record  Date for  the
payment of such defaulted interest which shall be not more than 15 nor less than
10  days prior to  the date of  the proposed payment  and not less  than 10 days
after the receipt  by the Trustee  of the  notice of the  proposed payment.  The
Trustee  shall promptly notify the  Company of such Special  Record Date and, in
the name and at the expense of  the Company, shall cause notice of the  proposed
payment  of such defaulted interest  and the Special Record  Date therefor to be
mailed, first class postage prepaid, to each  holder of the bonds of the  Series
due           , at his address as it appears in the bond register, not less than
10  days prior to  such Special Record  Date. Notice of  the proposed payment of
such defaulted interest and the Special Record Date therefor having been  mailed
as  aforesaid, such  defaulted interest  shall be paid  to the  persons in whose
names the bonds of the Series  due             , are registered on such  Special
Record  Date  and shall  not be  payable pursuant  to the  paragraph immediately
following in this Section 2.01.

    The Company may make payment of  any defaulted interest in any other  lawful
manner  not inconsistent  with the  requirements of  any securities  exchange on
which the bonds of  the Series due              , may be  listed, and upon  such
notice  as may be  required by such exchange,  if, after notice  is given by the
Company to the Trustee  of the proposed payment  pursuant to this Section  2.01,
such payment shall be deemed practicable by the Trustee.

    SECTION  2.02. The bonds of the Series due            , shall be redeemable,
other than for the Sinking Fund for bonds of that series provided for in Article
III hereof, at the option of the Company as a whole or in part on any date  upon
not  less than 30 days' previous  notice to be given in  the manner and with the
effect provided in Section 2 of Article X of the 1937 Indenture (except that, on
and after the  Effective Date,  such notice  shall be  given in  the manner  and
effect  provided  in Section  10.02 of  the Indenture)  at the  principal amount
thereof, with accrued  interest thereon  to the date  of redemption  and at  the
applicable  premium on  the principal amount  specified in  the tabulation below
under the heading  "Regular Redemption Premium,"  provided that no  bond of  the
Series  due           , shall be redeemed (other than through said Sinking Fund)
prior to           and the bonds of the Series due           , shall be  subject
to  call for redemption at par  for the Sinking Fund on  December 1 of each year
beginning    , upon  not less than 30 days' previous  notice to be given in  the
manner  and with the effect  provided in Article III hereof  and in Section 2 of
Article X of the 1937 Indenture (except  that, on and after the Effective  Date,
such notice shall be given in the manner and effect provided in Section 10.02 of
the  Indenture and in  Article III hereof)  at the principal  amount thereof and
accrued interest thereon to the date of redemption;

<TABLE>
<CAPTION>
 IF REDEEMED DURING                          IF REDEEMED DURING
         THE                                         THE
    TWELVE MONTH       REGULAR REDEMPTION       TWELVE MONTH       REGULAR REDEMPTION
  PERIOD BEGINNING           PREMIUM          PERIOD BEGINNING           PREMIUM
- ---------------------  -------------------  ---------------------  -------------------

<S>                    <C>                  <C>                    <C>
</TABLE>

    The redemption prices of the bonds of the Series due           , need not be
specified in any temporary  bond of said series  if an appropriate reference  be
made in said temporary bond to the provision of this Section.

    [The  bonds of the Series due           are not redeemable prior to maturity
for any reason and are not subject to a sinking fund.]

    SECTION 2.03. The registered owner  of any bond or  bonds of the Series  due
          , at his option may surrender the same with other bonds of said series
at  the office  of the  Trustee in Chicago,  Illinois, or  at the  agency of the
Company in the Borough of Manhattan, City and State of New York, or elsewhere if
authorized by
<PAGE>
                                       9

the Company, for cancellation, in exchange for other bonds of the said series of
higher or lower authorized  denominations, but of  the same aggregate  principal
amount, bearing interest from its date, and upon receipt of any payment required
under the provisions of Section 2.04 hereof. Thereupon the Company shall execute
and  deliver to the Trustee and the  Trustee shall authenticate and deliver such
other registered bonds to such  registered owner at its  office or at any  other
place specified as aforesaid.

    [Notwithstanding  the provisions  of Section  11 of  Article II  of the 1937
Indenture, the Company shall not be required to issue, transfer or exchange  any
bond  of the  Series due               , during a  period of ten  (10) days next
preceding any selection of bonds of the Series due            , to be  redeemed.
The Company shall not be required to transfer or exchange any bond of the Series
due              , called or  being called for redemption  in its entirety or to
transfer or exchange the called portion of a bond of the Series due            ,
which has been called for partial redemption.]

    SECTION  2.04. No charge  shall be made  by the Company  for any exchange or
transfer of bonds of the Series due             , other than for taxes or  other
governmental charges, if any, that may be imposed in relation thereto.

    SECTION  2.05. The bonds of the Series due            , shall be executed on
behalf of the Company  by the manual  signature of its President  or one of  its
Vice  Presidents  or with  the  facsimile signature  of  its President,  and its
corporate seal shall be thereunto affixed, or printed, lithographed, or engraved
thereon, in facsimile, and attested by the manual signature of its Secretary  or
one  of  its  Assistant  Secretaries  or with  the  facsimile  signature  of its
Secretary. In  case any  of the  officers who  shall have  signed any  bonds  or
attested  the seal thereon  or whose facsimile  signature shall be  borne by the
bonds shall cease to be such officers of the Company before the bonds so  signed
and sealed actually shall have been authenticated by the Trustee or delivered by
the Company, such bonds nevertheless may be issued, authenticated, and delivered
with  the same force and effect as though  the person or persons who signed such
bonds and attested the seal thereon or whose facsimile signature is borne by the
bonds had not ceased  to be such  officer or officers of  the Company. Any  bond
issuable hereunder may be signed or attested by manual or facsimile signature in
behalf  of the Company by such person as  at the actual date of the execution of
such bond shall be the  proper officer of the Company,  although at the date  of
such bond such person shall not have been an officer of the Company.

    SECTION  2.06. (a) Except as provided in  subsections (c) and (g) below, the
registered holder of all of the bonds of the Series due            shall be  The
Depository  Trust Company ("DTC") and the  bonds of the Series due             ,
shall be registered in the  name of Cede & Co.,  as nominee for DTC. Payment  of
principal  of[, premium, if  any,] and interest  on any bonds  of the Series due
          registered in the name of Cede & Co. shall be made by transfer of  New
York Federal or equivalent immediately available funds with respect to the bonds
of  the Series due            to the account  of Cede & Co. on each such payment
date for the bonds of the Series due           at the address indicated for Cede
& Co. in the bond register kept by the Trustee.

    (b) The bonds of the Series due            shall be initially issued in  the
form  of a  separate single  authenticated fully  registered certificate  in the
aggregate principal amount of  the bonds of  the Series due              .  Upon
initial  issuance, the ownership of such bonds of the Series due           shall
be registered in the  bond register kept by  the Trustee in the  name of Cede  &
Co.,  as nominee  of DTC.  The Trustee  and the  Company may  treat DTC  (or its
nominee) as the sole and exclusive registered holder of the bonds of the  Series
due                registered  in its name  for the  purposes of  payment of the
principal of[, premium, if  any,] and interest  on the bonds  of the Series  due
          ,  and  of giving  any notice  permitted  or required  to be  given to
holders under the Indenture,  except as provided in  Section 2.06(g) below;  and
neither  the Trustee  nor the  Company shall  be affected  by any  notice to the
contrary. Neither the Trustee nor the  Company shall have any responsibility  or
obligation  to  any of  DTC's participants  (each  a "Participant"),  any person
claiming a beneficial ownership in the bonds of the Series due           , under
or through DTC  or any  Participant (each a  "Beneficial Owner"),  or any  other
person  which is  not shown on  the bond  register maintained by  the Trustee as
being a  registered  holder,  with  respect  to  the  accuracy  of  any  records
maintained  by DTC or any Participant; the  payment of DTC or any Participant of
any amount in respect of  the principal of [, premium,  if any,] or interest  on
<PAGE>
                                       10

the  bonds of  the Series due               ;  any notice which  is permitted or
required to be given to registered holders  under the Indenture of bonds of  the
Series  due             ; or  any consent given or other  action taken by DTC as
bondholder. The Trustee  shall pay  all principal of  [, premium,  if any,]  and
interest on the bonds of the Series due           registered in the name of Cede
&  Co. only to or "upon  the order of" DTC (as that  term is used in the Uniform
Commercial Code as  adopted in Minnesota  and New York),  and all such  payments
shall  be  valid and  effective  to fully  satisfy  and discharge  the Company's
obligations with respect to the principal  of [, premium, if any,] and  interest
on  such bonds of the Series due             to the extent of the sum or sums so
paid. Except as otherwise provided in Sections 2.06(c) and (g) below, no  person
other  than  DTC shall  receive authenticated  bond certificates  evidencing the
obligation of the Company to make payments  of principal of and interest on  the
bonds  of the Series  due             .  Upon delivery by DTC  to the Trustee of
written notice to the effect that DTC has determined to substitute a new nominee
in place of  Cede & Co.,  and subject to  the provisions of  the Indenture  with
respect  to transfers of bonds, the word "Cede & Co." in this Supplemental Trust
Indenture shall refer to such new nominee of DTC.

    (c) If the  Company in  its discretion  determines that  it is  in the  best
interest of the Beneficial Owners that they be able to obtain bond certificates,
the  Company  may notify  DTC and  the  Trustee, whereupon  DTC will  notify the
Participants of  the availability  through  DTC of  bond certificates.  In  such
event,  the  Trustee  shall issue,  transfer  and exchange  bond  certificate as
requested by  DTC in  appropriate amounts  pursuant to  Article II  of the  1937
Indenture  prior to the Effective Date, Article  II of the Restated Indenture on
and after  the  Effective Date  and  Section  2.03 of  this  Supplemental  Trust
Indenture.  The Company shall pay all costs in connection with the production of
bond certificates if the Company makes  such a determination under this  Section
2.06(c). DTC may determine to discontinue providing its services with respect to
the  bonds of the Series due             at any time by giving written notice to
the Company and the  Trustee and discharging  its responsibilities with  respect
thereto under applicable law. Under such circumstances (if there is no successor
book-entry  depository), the Company and the  Trustee shall be obligated (at the
sole cost and expense of the Company) to deliver bond certificates as  described
in  this  Supplemental Trust  Indenture. If  bond  certificates are  issued, the
provisions of the Indenture shall apply to, among other things, the transfer and
exchange of such  certificates and  the method of  payment and  principal of  [,
premium,  if any,] and interest on  such certificates. Whenever DTC requests the
Company and the Trustee to  do so, the Company will  direct the Trustee (at  the
sole  cost  and  expense  of  the  Company)  to  cooperate  with  DTC  in taking
appropriate action after  reasonable notice (1)  to make available  one or  more
separate  certificates evidencing the bonds of the  Series due            to any
Participant or  (2) to  arrange for  another book-entry  depository to  maintain
custody  of certificates  evidencing the bonds  of the Series  due
registered in the name of Cede & Co. Any successor book-entry depository must be
a clearing  agency  registered  with  the  Securities  and  Exchange  Commission
pursuant  to Section 17A of  the Securities Exchange Act  of 1934 and must enter
into an  agreement with  the Company  and the  Trustee agreeing  to act  as  the
depository and clearing agency for the bonds of the Series due           (except
as  provided  in  Section  2.06(g)  below).  After  such  agreement  has  become
effective, DTC  shall present  the bonds  of the  Series due                 for
registration of transfer in accordance with Section 12 of Article II of the 1937
Indenture prior to the Effective Date and Section 2.12 of the Restated Indenture
on and after the Effective Date, and the Trustee shall register them in the name
of the successor book-entry depository or its nominee. If a successor book-entry
depository  has not  accepted such position  before the effective  date of DTC's
termination of its services, the book-entry system shall automatically terminate
and may not be reinstated without the  consent of all registered holders of  the
bonds of the Series due           .

    (d) Notwithstanding any other provision of this Supplemental Trust Indenture
to the contrary, so long as any bonds of the Series due           are registered
in  the name of Cede & Co., as nominee  of DTC, all payments with respect to the
principal of [, premium, if any,] and  interest on such Bonds of the Series  due
          and  all  notices  with  respect  to  such  bonds  of  the  Series due
          shall be  made and  given, respectively,  to DTC  as provided  in  the
representation  letter dated  as of  the date  of delivery  of the  bonds of the
Series due             among  DTC, the Company and  the Trustee. The Trustee  is
hereby  authorized and directed  to comply with all  terms of the representation
letter.
<PAGE>
                                       11

    (e) In connection  with any  notice or  other communication  to be  provided
pursuant  to the Indenture  for the bonds of  the Series due              by the
Company or the Trustee with respect to  any consent or other action to be  taken
by the registered holders of the bonds of the Series due           , the Company
or the Trustee, as the case may be, shall seek to establish a record date to the
extent  permitted by the Indenture for such consent or other action and give DTC
notice of such record date not less  than fifteen (15) calendar days in  advance
of  such record date to  the extent possible. Such notice  to DTC shall be given
only when DTC is the sole registered holder.

    (f) NEITHER THE  COMPANY NOR  THE TRUSTEE  WILL HAVE  ANY RESPONSIBILITY  OR
OBLIGATIONS TO THE PARTICIPANTS OR THE BENEFICIAL OWNERS WITH RESPECT TO (1) THE
ACCURACY OF ANY RECORDS MAINTAINED BY DTC OR ANY PARTICIPANT; (2) THE PAYMENT BY
DTC  OR ANY PARTICIPANT OF ANY AMOUNT DUE  TO ANY BENEFICIAL OWNER IN RESPECT OF
THE PRINCIPAL OF [, PREMIUM, IF ANY,] OR INTEREST ON THE BONDS OF THE SERIES DUE
           ; (3) THE DELIVERY  BY DTC OR  ANY PARTICIPANT OF  ANY NOTICE TO  ANY
BENEFICIAL OWNER WHICH IS REQUIRED OR PERMITTED UNDER THE TERMS OF THE INDENTURE
TO BE GIVEN TO REGISTERED HOLDERS; (4) THE SELECTION OF THE BENEFICIAL OWNERS TO
RECEIVE  PAYMENT IN  THE EVENT  OF ANY  PARTIAL REDEMPTION  OF THE  BONDS OF THE
SERIES DUE            ; OR (5) ANY CONSENT GIVEN OR OTHER ACTION TAKEN BY DTC AS
A REGISTERED HOLDER.

    SO LONG AS CEDE &  CO. IS THE REGISTERED HOLDER  OF THE BONDS OF THE  SERIES
DUE            AS NOMINEE OF DTC, REFERENCES HEREIN TO REGISTERED HOLDERS OF THE
BONDS  OF THE SERIES DUE            SHALL MEAN CEDE & CO. AND SHALL NOT MEAN THE
BENEFICIAL OWNERS  OF THE  BONDS  OF THE  SERIES DUE                    NOR  DTC
PARTICIPANTS.

    (g)  The Company, in its sole discretion,  may terminate the services of DTC
with respect to the bonds of the Series due           if the Company  determines
that:  (i) DTC is unable  to discharge its responsibilities  with respect to the
bonds of the Series due             ; or (ii) a continuation of the  requirement
that all of the outstanding bonds of the Series due           be registered with
the registration books kept by the Trustee in the name of Cede & Co., as nominee
of DTC, is not in the best interest of the Beneficial Owners of the bonds of the
Series  due                . After  such event  and if  no substitute book-entry
depository is appointed by the Company,  bond certificates will be delivered  as
described in the Indenture.

    (h) Upon the termination of the services of DTC with respect to the bonds of
the Series due           pursuant to subsections (c) or (g) of this Section 2.06
after  which no substitute book-entry depository  is appointed, the bonds of the
Series due              shall be  registered in whatever  name or names  holders
transferring  or exchanging bonds of the Series due           shall designate in
accordance with the provisions of the Indenture.

                                  ARTICLE III.
                                 SINKING FUND.

    SECTION 3.01. (a) The  Company covenants that  it will on  the first day  of
October of each year commencing October 1,    , and continuing so long as any of
the bonds of the Series due           , are outstanding, pay or cause to be paid
to  the Trustee, for  and as a  fund for the  use and benefit  of the holders of
bonds of the Series due            , a sum in lawful money of the United  States
of  America equal to the amount required to  redeem on the first day of December
next following the date of such payment, in accordance with Section 3.02, 1%  of
the  highest aggregate  principal amount  of bonds  of that  series at  any time
outstanding. Such fund shall  be the Sinking  Fund for bonds  of the Series  due
          .  [The Company covenants that it  will meet its obligations under the
immediately preceding sentence for the year 199 solely and entirely through  the
application of permanent additions (or, if after the Effective Date, through the
application  of  an Amount  of Established  Permanent  Additions) in  the manner
hereinafter set forth in subdivision (c) of this Section 3.01.]
<PAGE>
                                       12

    (b)  The delivery by the Company to  the Trustee of bonds of the Series  due
          ,  shall, for the purposes of satisfying the Sinking Fund for bonds of
that series, be  deemed equivalent  under this Section  to the  payment of  cash
equal  to the amount required to effect the redemption of the bonds so delivered
on the first day of December next  following such delivery. If any bonds of  the
Series  due                ,  have been  redeemed or  retired and  no bonds have
theretofore been  issued, cash  withdrawn,  or credit  taken  under any  of  the
provisions  of the Indenture on account of  the redemption or retirement of such
bonds, the Company may deduct from any payment for the Sinking Fund for bonds of
the Series due           , an amount equivalent to the amount required to effect
the redemption of a like amount of bonds of that series for the Sinking Fund for
bonds of the Series due           , on the first day of December next following,
provided that the  Company thereafter shall  not issue any  bonds, withdraw  any
cash, or take any credit under any of the provisions of the Indenture on account
of the redemption or retirement of such bonds and such bonds shall be cancelled.
For  the purpose of  this subdivision (b),  credit shall be  deemed to have been
taken for any bonds redeemed or retired if used as a reduction of the amount  of
cash  required  to be  deposited with  the  Trustee under  any provision  of the
Indenture or out of funds  pledged with the Trustee  under any provision of  the
Indenture,  other than funds deposited with the Trustee for the payment of bonds
upon maturity or upon redemption at the option of the Company.

    (c)  Prior to the Effective Date, the delivery by the Company to the Trustee
of a written  application of  the Company,  signed by  its President  or a  Vice
President,  to apply permanent additions acquired  or constructed by the Company
(which, under the provisions of Article V  of the 1937 Indenture, as amended  by
the Supplemental Trust Indenture thereto dated February 1, 1944, might otherwise
be  made the basis for the issuance of the bonds thereunder) to the Sinking Fund
provided for bonds of the Series due            for the purpose of such  Sinking
Fund  shall be deemed equivalent under this Section to the payment of cash equal
to the amount required  to effect the  redemption on the  first day of  December
next  following, of bonds of the  Series due             , in an amount equal to
66 2/3% of the cost or fair value, whichever is less, of the permanent additions
so applied, after making the deductions provided  for in Section 3 of Article  V
of  the 1937 Indenture to a date not more than 90 days preceding the date of the
delivery to the Trustee of such application, on account of property removed from
service or  abandoned and  not replaced  or offset;  provided that  the  Company
thereafter  shall not  issue any  bonds, withdraw any  cash, or  take any credit
under any of the  provisions of the  Indenture upon the  basis of the  permanent
additions  so applied. Prior to the Effective  Date, such an application in each
case  shall  be   accompanied  by  the   resolutions,  certificates,   opinions,
instruments,  and other papers provided  for in Subsection (B)  of Section 10 of
Article XI of the 1937 Indenture, as amended by the Supplemental Trust Indenture
thereto dated February 1, 1944, in case  of withdrawal of cash from the  Release
Fund with such omissions or variations therefrom or insertions therein as may be
appropriate  in the light of  the purpose for which they  are used. On and after
the Effective Date,  the delivery by  the Company  to the Trustee  of a  written
application of the Company signed by its President or a Vice President, to apply
an Amount of Established Permanent Additions established as provided in Sections
5.05  and 5.06 of  the Indenture (which  has not been  applied previously to any
other purpose specified in  the Indenture) to the  Sinking Fund provided for  in
this  Article III, for purposes of said  Sinking Fund shall be deemed equivalent
under this Section to the payment of cash equal to the amount required to effect
the redemption  on the  first day  of December  next following,  of a  principal
amount  of Bonds of  this Series equal to  66 2/3% of  the Amount of Established
Permanent Additions so applied.

    SECTION 3.02. (a) As soon as may be, after each payment to the Sinking  Fund
provided  for bonds of the Series due            , is so made, the Trustee shall
apply the moneys in such Sinking Fund to the purchase of bonds of the Series due
          , in the open  market, at the lowest  price or prices obtainable,  but
not  to exceed the price  at which the bonds of  such series are then redeemable
for the Sinking Fund as herein provided. If within 20 days after each payment to
the Sinking Fund, the Trustee  shall be unable to  purchase bonds of the  Series
due            ,  as aforesaid, sufficient to reduce the amount of money held in
the Sinking Fund to less than $10,000, the Trustee shall apply the Sinking  Fund
for  bonds of  the Series  due                ,  or the  balance thereof  to the
redemption, on the first day of December next following the receipt of such cash
by the Trustee, of bonds  of such series at  the sinking fund redemption  prices
provided for in Section 2.02 of this Supplemental Trust Indenture.
<PAGE>
                                       13

    (b)   The  particular bonds  to be  redeemed for  the Sinking  Fund shall be
selected by the Trustee by  lot, in such manner as  it shall deem proper in  its
discretion,  from the  distinctive numbers  borne by  or assigned  to registered
bonds of the Series due           , as herein provided. For each registered bond
of a denomination in  excess of $1,000, the  Trustee shall assign a  distinctive
number of each $1,000 of the principal amount thereof. Registered bonds shall be
deemed  to have been drawn by lot if and to the extent that the numbers borne by
or assigned thereto  as above provided  are selected as  aforesaid. The  Trustee
shall  notify the Company in writing of  the distinctive numbers of the bonds of
the Series due            , to be redeemed for the Sinking Fund. The Trustee  is
authorized  and empowered hereby to  give or cause to be  given on behalf of the
Company the notice required by Section 2.02 hereof in order to redeem bonds  for
Sinking Fund purposes.

    (c)  On and after the commencement of notice of redemption of bonds pursuant
to  this Section, the Trustee  shall (subject to the  provisions of Section 5 of
Article XX  of  the 1937  Indenture  prior to  the  Effective Date  and  to  the
provisions  of Section 20.03 of  the Indenture on and  after the Effective Date)
hold the moneys necessary to  redeem the bonds so to  be redeemed as a  separate
trust  fund for the  account of the  respective holders thereof  and such moneys
shall be  paid to  them respectively  upon presentation  and surrender  of  such
bonds;  and after the redemption date, such  bonds shall cease to be entitled to
the lien, benefits, or security of the Indenture, and as respects the  Company's
liability thereon such bonds and all claims for interest thereon shall be deemed
to  have been paid; this Section being in all respects subject to the provisions
of Section 5 of Article XX of the 1937 Indenture prior to the Effective Date and
to the provisions of Section 20.03 of  the Indenture on and after the  Effective
Date,  except that, on and  after commencement of notice  of redemption of bonds
pursuant to this Section 3.02, such bonds shall be deemed to have been  redeemed
from  the holder  or holders  thereof and  paid for  the purpose  of release and
satisfaction of the Indenture.

    (d)  If  there shall  be drawn  for redemption  a portion  of the  principal
amount  less than the  entire amount of  any registered bond,  the Company shall
execute and the  Trustee shall authenticate  and deliver without  charge to  the
holder thereof registered bonds of the Series due           , for the unredeemed
balance of such registered bond.

    SECTION  3.03.  All bonds  delivered  to the  Trustee  in lieu  of  cash, or
purchased by  the Trustee,  or redeemed  by  operation of  the Sinking  Fund  in
accordance  with  the provisions  of  this Article,  shall  be cancelled  by the
Trustee. Bonds so cancelled shall not be reissued and no additional bonds  shall
be  authenticated and  delivered in substitution  therefor or on  account of the
retirement thereof and  no credit  shall be taken  or cash  withdrawn under  the
provisions of the Indenture on the basis thereof.

                                  ARTICLE IV.
                      APPOINTMENT OF AUTHENTICATING AGENT.

    SECTION  4.01. The Trustee  shall, if requested  in writing so  to do by the
Company, promptly  appoint an  agent or  agents of  the Trustee  who shall  have
authority  to authenticate registered bonds of the Series due           , in the
name and on  behalf of the  Trustee. Such  appointment by the  Trustee shall  be
evidenced  by a certificate of a vice-president  of the Trustee delivered to the
Company prior to the effectiveness of such appointment.

    SECTION 4.02. (a)  Any such authenticating agent shall be acceptable to  the
Company  and at all  times shall be  a corporation which  is organized and doing
business under the  laws of the  United States  or of any  State, is  authorized
under  such laws  to act  as authenticating  agent, has  a combined  capital and
surplus of at least $10,000,000, and is subject to supervision or examination by
Federal or State authority. If  such corporation publishes reports of  condition
at  least annually,  pursuant to  law or  to the  requirements of  the aforesaid
supervising or examining authority, then for  the purposes of this Section  4.02
the  combined capital and surplus of such  corporation shall be deemed to be its
combined capital and surplus as set forth in its most recent report of condition
so published.

    (b)  Any corporation  into which any authenticating  agent may be merged  or
converted  or with  which it may  be consolidated, or  any corporation resulting
from   any    merger,    conversion,    or   consolidation    to    which    any
<PAGE>
                                       14

authenticating  agent shall  be a  party, or  any corporation  succeeding to the
corporate agency business of any authenticating agent, shall continue to be  the
authenticating agent without the execution or filing of any paper or any further
act on the part of the Trustee or the authenticating agent.

    (c)   Any  authenticating agent  at any  time may  resign by  giving written
notice of resignation to the Trustee and to the Company. The Trustee may at  any
time,  and upon written request  of the Company to  the Trustee shall, terminate
the agency of any authenticating agent  by giving written notice of  termination
to such authenticating agent and to the Company. Upon receiving such a notice of
resignation   or  upon  such  a  termination,  or   in  case  at  any  time  any
authenticating  agent  shall  cease  to  be  eligible  in  accordance  with  the
provisions  of this  Section 4.02,  the Trustee,  unless otherwise  requested in
writing by the Company, promptly shall appoint a successor authenticating agent,
which shall be  acceptable to  the Company. Any  successor authenticating  agent
upon  acceptance of its  appointment hereunder shall become  vested with all the
rights, powers, duties, and responsibilities of its predecessor hereunder,  with
like  effect as if originally named.  No successor authenticating agent shall be
appointed unless eligible under the provisions of this Section 4.02.

    (d)  The  Trustee agrees to  pay to any  authenticating agent, appointed  in
accordance with the provisions of this Section 4.02, reasonable compensation for
its  services,  and the  Trustee shall  be  entitled to  be reimbursed  for such
payments.

    SECTION 4.03. If  an appointment is  made pursuant to  this Article IV,  the
registered  bonds of the Series due            , shall have endorsed thereon, in
addition to the Trustee's Certificate, an alternate Trustee's Certificate in the
following form:

    This bond is one of the bonds of the Series designated thereon, described in
the within-mentioned Indenture.
                                              HARRIS TRUST AND SAVINGS BANK,
                                                                   as Trustee,

                                          By
                                                  Authenticating Agent,

                                          By
                                                   Authorized Officer.

    SECTION 4.04. No provision of this  Article IV shall require the Trustee  to
have at any time more than one such authenticating agent for any one State or to
appoint  any such authenticating agent in the State in which the Trustee has its
principal place of business.
<PAGE>
                                       15

                                   ARTICLE V.
        FINANCING STATEMENT TO COMPLY WITH THE UNIFORM COMMERCIAL CODE.

    SECTION  5.01. The name and address of  the debtor and secured party are set
forth below:

           Debtor: Northern States Power Company
                  414 Nicollet Mall
                  Minneapolis, Minnesota 55401

           Secured Party: Harris Trust and Savings Bank, Trustee
                       111 West Monroe Street
                       Chicago, Illinois 60603

    NOTE:  Northern  States  Power  Company,  the  debtor  above  named,  is  "a
transmitting utility" under the Uniform Commercial Code as adopted in Minnesota,
North Dakota and South Dakota.

    SECTION 5.02. Reference to Article I hereof is made for a description of the
property  of the debtor covered by this  Financing Statement with the same force
and effect as if incorporated in this Section at length.

    SECTION 5.03.  The  maturity  dates  and  respective  principal  amounts  of
obligations  of the debtor secured and presently to be secured by the Indenture,
reference to all of which  for the terms and  conditions thereof is hereby  made
with  the same  force and  effect as  if incorporated  herein at  length, are as
follows.

<TABLE>
<CAPTION>
FIRST MORTGAGE BONDS                                                          PRINCIPAL AMOUNT
- ----------------------------------------------------------------------------  ----------------
<S>                                                                           <C>
Series due October 1, 1997..................................................   $  100,000,000
Series due February 1, 1999.................................................   $  200,000,000
Series due October 1, 2001..................................................   $  150,000,000
Series due December 1, 2000.................................................   $  100,000,000
Series due March 1, 2002....................................................   $   50,000,000
Series due February 1, 2003.................................................   $   50,000,000
Series due April 1, 2003....................................................   $   80,000,000
Series due December 1, 2005.................................................   $   70,000,000
Pollution Control Series C..................................................   $    8,800,000
Resource Recovery Series I..................................................   $   22,300,000
Pollution Control Series J..................................................   $    5,450,000
Pollution Control Series K..................................................   $    3,400,000
Pollution Control Series L..................................................   $    4,850,000
Series due July 1, 2025.....................................................   $  250,000,000
</TABLE>

    SECTION 5.04. This  financing Statement  is hereby  adopted for  all of  the
First Mortgage Bonds of the series mentioned above secured by said Indenture.

    SECTION   5.05.  The  1937  Indenture   and  the  prior  Supplemental  Trust
Indentures, as set forth below,  have been filed or  recorded in each and  every
office  in the States of Minnesota, North Dakota, and South Dakota designated by
law for  the filing  or recording  thereof in  respect of  all property  of  the
Company subject thereto:

    Original Indenture
      Dated February 1, 1937

    Supplemental Indenture
      Dated June 1, 1942

    Supplemental Indenture
      Dated February 1, 1944

    Supplemental Indenture
      Dated October 1, 1945

    Supplemental Indenture
      Dated July 1, 1948

    Supplemental Indenture
      Dated August 1, 1949

    Supplemental Indenture
      Dated June 1, 1952

    Supplemental Indenture
      Dated October 1, 1954
<PAGE>
                                       16

    Supplemental Indenture
      Dated September 1, 1956

    Supplemental Indenture
      Dated August 1, 1957

    Supplemental Indenture
      Dated July 1, 1958

    Supplemental Indenture
      Dated December 1, 1960

    Supplemental Indenture
      Dated August 1, 1961

    Supplemental Indenture
      Dated June 1, 1962

    Supplemental Indenture
      Dated September 1, 1963

    Supplemental Indenture
      Dated August 1, 1966

    Supplemental Indenture
      Dated June 1, 1967

    Supplemental Indenture
      Dated October 1, 1967

    Supplemental Indenture
      Dated May 1, 1968

    Supplemental Indenture
      Dated October 1, 1969

    Supplemental Indenture
      Dated February 1, 1971

    Supplemental Indenture
      Dated May 1, 1971

    Supplemental Indenture
      Dated February 1, 1972

    Supplemental Indenture
      Dated January 1, 1973

    Supplemental Indenture
      Dated January 1, 1974

    Supplemental Indenture
      Dated September 1, 1974

    Supplemental Indenture
      Dated April 1, 1975

    Supplemental Indenture
      Dated May 1, 1975

    Supplemental Indenture
      Dated March 1, 1976

    Supplemental Indenture
      Dated June 1, 1981

    Supplemental Indenture
      Dated December 1, 1981

    Supplemental Indenture
      Dated May 1, 1983

    Supplemental Indenture
      Dated December 1, 1983

    Supplemental Indenture
      Dated September 1, 1984

    Supplemental Indenture
      Dated December 1, 1984

    Supplemental Indenture
      Dated May 1, 1985

    Supplemental Indenture
      Dated September 1, 1985

    Supplemental and Restated Indenture
      Dated May 1, 1988

    Supplemental Indenture
      Dated July 1, 1989

    Supplemental Indenture
      Dated June 1, 1990

    Supplemental Indenture
      Dated October 1, 1992

    Supplemental Indenture
      Dated April 1, 1993

    Supplemental Indenture
      Dated December 1, 1993

    Supplemental Indenture
      Dated February 1, 1994

    Supplemental Indenture
      Dated October 1, 1994

    Supplemental Indenture
      Dated June 1, 1995

    SECTION  5.06. The property  covered by this  Financing Statement also shall
secure additional series  of First  Mortgage Bonds of  the debtor  which may  be
issued  from time to time in the future in accordance with the provisions of the
Indenture.
<PAGE>
                                       17

                                  ARTICLE VI.
                            AMENDMENTS TO INDENTURE.

    SECTION 6.01.  Each holder  or registered  owner  of a  bond of  any  series
originally  authenticated by  the Trustee and  originally issued  by the Company
subsequent to May 1, 1985 and of any coupon pertaining to any such bond, by  the
acquisition,  holding or ownership of such bond and coupon, thereby consents and
agrees to,  and  shall  be  bound  by, the  provisions  of  Article  VI  of  the
Supplemental  Indenture dated May 1, 1985. Each  holder or registered owner of a
bond of any series (including bonds  of the Series due             )  originally
authenticated  by the Trustee and originally issued by the Company subsequent to
May 1, 1988  and of  any coupon  pertaining to  such bond,  by the  acquisition,
holding  or ownership of such  bond and coupon, thereby  consents and agrees to,
and shall be  bound by, the  provisions of the  Supplemental and Restated  Trust
Indenture dated May 1, 1988 upon the Effective Date.

                                  ARTICLE VII.
                                 MISCELLANEOUS.

    SECTION  7.01.  The recitals  of fact  herein, except  the recital  that the
Trustee has duly determined to execute this Supplemental Trust Indenture and  be
bound,  insofar as it  may lawfully so do,  by the provisions  hereof and in the
bonds shall be taken as statements of the Company and shall not be construed  as
made  by the Trustee. The Trustee makes no representations as to value of any of
the property subjected to the lien of the Indenture, or any part thereof, or  as
to  the title of the Company thereto, or as to the security afforded thereby and
hereby, or as to  the validity of  this Supplemental Trust  Indenture or of  the
bonds  issued  under  the  Indenture  by  virtue  hereof  (except  the Trustee's
certificate), and the Trustee shall incur  no responsibility in respect of  such
matters.

    SECTION  7.02.  This  Supplemental  Trust Indenture  shall  be  construed in
connection with and  as a part  of the  1937 Indenture, as  supplemented by  the
Supplemental  Trust Indentures dated June 1,  1942, February 1, 1944, October 1,
1945, July 1, 1948, August 1, 1949, June 1, 1952, October 1, 1954, September  1,
1956,  August 1, 1957, July  1, 1958, December 1, 1960,  August 1, 1961, June 1,
1962, September 1, 1963, August 1, 1966,  June 1, 1967, October 1, 1967, May  1,
1968,  October 1, 1969, February 1, 1971, May 1, 1971, February 1, 1972, January
1, 1973, January 1, 1974, September 1,  1974, April 1, 1975, May 1, 1975,  March
1,  1976,  June  1, 1981,  December  1, 1981,  May  1, 1983,  December  1, 1983,
September 1,  1984,  December 1,  1984,  May 1,  1985,  September 1,  1985,  the
Supplemental and Restated Trust Indenture dated May 1, 1988 and the Supplemental
Trust  Indentures dated July  1, 1989, June  1, 1990, October  1, 1992, April 1,
1993, December 1,  1993, February 1,  1994, October  1, 1994, June  1, 1995  and
          .

    SECTION  7.03. (a)  If any  provision of  this Supplemental  Trust Indenture
limits, qualifies, or conflicts with another provision of the Indenture required
to be included in indentures qualified under the Trust Indenture Act of 1939 (as
enacted prior to the date  of this Supplemental Trust  Indenture) by any of  the
provisions  of Sections 310  to 317, inclusive,  of the said  Act, such required
provisions shall control.

    (b) In case any one or more of the provisions contained in this Supplemental
Trust Indenture or in the bonds issued hereunder should be invalid, illegal,  or
unenforceable  in any respect, the validity, legality, and enforceability of the
remaining provisions  contained herein  and  therein shall  not  in any  way  be
affected, impaired, prejudiced, or disturbed thereby.

    SECTION  7.04.  Wherever  in  this  Supplemental  Trust  Indenture  the word
"Indenture" is used  without the prefix,  "1937," "Original" or  "Supplemental",
such  word  was used  intentionally  to include  in  its meaning  both  the 1937
Indenture and all indentures supplemental thereto.

    SECTION 7.05. Wherever in  this Supplemental Trust  Indenture either of  the
parties  hereto is  named or referred  to, this  shall be deemed  to include the
successors or assigns  of such party,  and all the  covenants and agreements  in
this Supplemental Trust Indenture contained by or on behalf of the Company or by
or  on  behalf  of the  Trustee  shall bind  and  inure  to the  benefit  of the
respective successors and assigns of such parties, whether so expressed or not.
<PAGE>
                                       18

    SECTION  7.06.  (a)  This  Supplemental  Trust  Indenture  may  be  executed
simultaneously  in several counterparts, and  all said counterparts executed and
delivered,  each  as  an  original,  shall  constitute  but  one  and  the  same
instrument.

    (b)  The  Table of  Contents  and the  descriptive  headings of  the several
Articles of  this  Supplemental  Trust  Indenture  were  formulated,  used,  and
inserted in this Supplemental Trust Indenture for convenience only and shall not
be deemed to affect the meaning or construction of any of the provisions hereof.
                                 --------------

    The  amount of  obligations to  be issued  forthwith under  the Indenture is
$         .
                                 --------------
<PAGE>
                                       19

    IN WITNESS WHEREOF, on this  th day of    , A.D.    , NORTHERN STATES  POWER
COMPANY,  a  Minnesota corporation,  party  of the  first  part, has  caused its
corporate name and  seal to  be hereunto  affixed, and  this Supplemental  Trust
Indenture  dated            , to be signed by its President or a Vice President,
and attested by its Secretary or an Assistant Secretary, for and in its  behalf,
and HARRIS TRUST AND SAVINGS BANK, an Illinois corporation, as Trustee, party of
the  second part, to  evidence its acceptance  of the trust  hereby created, has
caused its corporate name and seal to be hereunto affixed, and this Supplemental
Trust Indenture dated                ,  to be signed  by its  President, a  Vice
President,  or an Assistant Vice President, and  attested by its Secretary or an
Assistant Secretary, for and in its behalf.

<TABLE>
<S>                                       <C>
                                          NORTHERN STATES POWER COMPANY,

                                          BY                     , VICE
                                          PRESIDENT

Attest:

                  , SECRETARY.

Executed by Northern States
Power Company in presence of:

                                                                (CORPORATE SEAL)

                      , WITNESSES.

                                                  HARRIS TRUST AND SAVINGS BANK,
                                                                      as Trustee

                                          BY             , VICE PRESIDENT

Attest:

          , ASSISTANT SECRETARY.

Executed by Harris Trust and Savings
Bank in presence of:

                                                                (CORPORATE SEAL)

        , WITNESSES.
</TABLE>

<PAGE>
                                       20

<TABLE>
<S>                   <C>
STATE OF MINNESOTA
COUNTY OF HENNEPIN    ss.:
</TABLE>

    On this  th day of    , A.D.     , before me,                           ,  a
Notary Public in and for said County in the State aforesaid, personally appeared
                     and                     , to me personally known, and to me
known to be Vice President and Secretary, respectively, of Northern States Power
Company, one of the corporations described in and which executed the within  and
foregoing  instrument, and who, being  by me severally duly  sworn, each did say
that he, the said                          is  Vice President, and he, the  said
                  ,  is  Secretary, of  said  Northern States  Power  Company, a
corporation; that the seal affixed to the within and foregoing instrument is the
corporate seal of  said corporation, and  that said instrument  was executed  in
behalf  of said  corporation by  authority of its  board of  directors; and said
                     and                   each acknowledged said instrument  to
be  the free act and deed of said corporation and that such corporation executed
the same.

    WITNESS my hand and notarial seal this  th day of    , A.D.    .

NOTARY PUBLIC, HENNEPIN COUNTY, MINN.
MY COMMISSION EXPIRES

                        (NOTARIAL SEAL)

<TABLE>
<S>                   <C>
STATE OF MINNESOTA
COUNTY OF HENNEPIN    ss.:
</TABLE>

                         and                      , being severally duly  sworn,
each  deposes and says  that he, the  said                             , is Vice
President, and he, the said                   , is Secretary, of Northern States
Power Company, the corporation  described in and which  executed the within  and
foregoing  Supplemental  Trust Indenture,  as  mortgagor; and  each  for himself
further says that said Supplemental Trust Indenture was executed in good  faith,
and  not for the purpose  of hindering, delaying, or  defrauding any creditor of
the said mortgagor.

    Subscribed and sworn to before me this  th day of    , A.D.    .

NOTARY PUBLIC, HENNEPIN COUNTY, MINN.
MY COMMISSION EXPIRES

                        (NOTARIAL SEAL)
<PAGE>
                                       21

<TABLE>
<S>                <C>
STATE OF ILLINOIS
COUNTY OF COOK     ss.:
</TABLE>

    On this  th day of    , A.D.     , before me,                    , a  Notary
Public  in  and for  said  County in  the  State aforesaid,  personally appeared
            and            , to me personally known, and to me known to be  Vice
President  and Assistant  Secretary, respectively,  of Harris  Trust and Savings
Bank, one of  the corporations described  in and which  executed the within  and
foregoing  instrument, and who, being  by me severally duly  sworn, each did say
that she, the  said                   ,  is Vice  President, and  she, the  said
          ,  is Assistant  Secretary, of said  Harris Trust and  Savings Bank, a
corporation; that the seal affixed to the within and foregoing instrument is the
corporate seal of  said corporation, and  that said instrument  was executed  in
behalf  of said  corporation by  authority of its  board of  directors; and said
            , and           each acknowledged said instrument to be the free act
and deed of said corporation and that such corporation executed the same.

    WITNESS my hand and notarial seal this  th day of      , A.D.    .

                                          NOTARY PUBLIC, COOK COUNTY, ILLINOIS.
                                          MY COMMISSION EXPIRES

(NOTARIAL SEAL)

<TABLE>
<S>                <C>
STATE OF ILLINOIS
COUNTY OF COOK     ss.:
</TABLE>

                and             , being severally  duly sworn, each for  herself
deposes  and says that she, the said               , is Vice President, and she,
the said            , is Assistant Secretary, of Harris Trust and Savings  Bank,
the  corporation  described  in  and which  executed  the  within  and foregoing
Supplemental Trust Indenture, as  mortgagor; and each  for herself further  says
that  said Supplemental Trust Indenture was executed  in good faith, and not for
the purpose of hindering, delaying, or defrauding any creditor of the mortgagor.

    Subscribed and sworn to before me this  th day of    , A.D.    .

                                          NOTARY PUBLIC, COOK COUNTY, ILLINOIS.
                                          MY COMMISSION EXPIRES

(NOTARIAL SEAL)
<PAGE>
                                      A-1

                                   SCHEDULE A

    The property referred to  in Article I of  the foregoing Supplemental  Trust
Indenture  from Northern States Power Company  to Harris Trust and Savings Bank,
Trustee, made as of           , includes the following property hereinafter more
specifically described. Such description, however,  is not intended to limit  or
impair  the  scope or  intention  of the  general  description contained  in the
granting clauses or elsewhere in the Original Indenture.

                     I.  PROPERTY IN THE STATE OF MINNESOTA

<PAGE>
                                      A-2

                                 --------------

                         MORTGAGOR'S RECEIPT FOR COPY.

    The undersigned Northern  States Power Company,  the Mortgagor described  in
the foregoing Mortgage, hereby acknowledges that at the time of the execution of
the  Mortgage, Harris Trust  and Savings Bank,  Trustee, the Mortgagee described
therein, surrendered to  it a  full, true, complete,  and correct  copy of  said
instrument, with signatures, witnesses, and acknowledgments thereon shown.

                                              NORTHERN STATES POWER COMPANY.

                                              BY                     , VICE
                                                        PRESIDENT

Attest:

                 , SECRETARY
                                 --------------

    This  instrument was drafted by Northern  States Power Company, 414 Nicollet
Mall, Minneapolis, Minnesota 55401.

    Tax statements for the real property described in this instrument should  be
sent to Northern States Power Company, 414 Nicollet Mall, Minneapolis, Minnesota
55401.
