EXHIBIT 4-12




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                         FIRST SUPPLEMENTAL INDENTURE

                         Dated as of January 31, 1997

                                  between

                        NORTHERN STATES POWER COMPANY,

                                 AS ISSUER

                                    and

                          NORWEST BANK MINNESOTA,
                           NATIONAL ASSOCIATION,

                                 AS TRUSTEE



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                             TABLE OF CONTENTS

                                                                           Page
                                                                           ----
ARTICLE I. DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .  2

     SECTION 1.1.  Definition of Terms.. . . . . . . . . . . . . . . . . . .  2

ARTICLE II. GENERAL TERMS AND CONDITIONS OF THE DEBENTURES . . . . . . . . .  3

     SECTION 2.1.  Designation and Principal Amount. . . . . . . . . . . . .  3
     SECTION 2.2.  Maturity. . . . . . . . . . . . . . . . . . . . . . . . .  3
     SECTION 2.3. Form and Payment . . . . . . . . . . . . . . . . . . . . .  3
     SECTION 2.4.  Global Debenture. . . . . . . . . . . . . . . . . . . . .  3
     SECTION 2.5.  Interest. . . . . . . . . . . . . . . . . . . . . . . . .  5
     SECTION 2.6.  Preferred Security Holders' Rights  . . . . . . . . . . .  5

ARTICLE III. REDEMPTION OF THE DEBENTURES. . . . . . . . . . . . . . . . . .  6

     SECTION 3.1.  Tax Event Redemption. . . . . . . . . . . . . . . . . . .  6
     SECTION 3.2.  Optional Redemption by Company. . . . . . . . . . . . . .  6
     SECTION 3.3.  No Sinking Fund . . . . . . . . . . . . . . . . . . . . .  7

ARTICLE IV. EXTENSION OF INTEREST PAYMENT PERIOD . . . . . . . . . . . . . .  7

     SECTION 4.1.  Extension of Interest Payment Period. . . . . . . . . . .  7
     SECTION 4.2.  Notice of Extension . . . . . . . . . . . . . . . . . . .  8
     SECTION 4.3.  Limitation of Transactions. . . . . . . . . . . . . . . .  8

ARTICLE V. EXPENSES. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  9

     SECTION 5.1.  Payment of Expenses . . . . . . . . . . . . . . . . . . .  9
     SECTION 5.2.  Payment Upon Resignation or Removal . . . . . . . . . . .  9

ARTICLE VI. NOTICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

     SECTION 6.1.  Notice by the Company . . . . . . . . . . . . . . . . . . 10

ARTICLE VII. COVENANT TO LIST ON EXCHANGE. . . . . . . . . . . . . . . . . . 10

     SECTION 7.1.  Listing on an Exchange. . . . . . . . . . . . . . . . . . 10

ARTICLE VIII. FORM OF DEBENTURE. . . . . . . . . . . . . . . . . . . . . . . 11

     SECTION 8.1.  Form of Debenture . . . . . . . . . . . . . . . . . . . . 11

ARTICLE IX. ORIGINAL ISSUE OF DEBENTURES . . . . . . . . . . . . . . . . . . 20

     SECTION 9.1.  Original Issue of Debentures. . . . . . . . . . . . . . . 20


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ARTICLE X. MISCELLANEOUS . . . . . . . . . . . . . . . . . . . . . . . . . . 20

     SECTION 10.1.  Ratification of Indenture. . . . . . . . . . . . . . . . 20
     SECTION 10.2.  Trustee Not Responsible for Recitals.. . . . . . . . . . 20
     SECTION 10.3.  Governing Law. . . . . . . . . . . . . . . . . . . . . . 20
     SECTION 10.4.  Separability.. . . . . . . . . . . . . . . . . . . . . . 20
     SECTION 10.5.  Counterparts.. . . . . . . . . . . . . . . . . . . . . . 21


                                      ii



    FIRST SUPPLEMENTAL INDENTURE, dated as of January 31, 1997 (the 
"First Supplemental Indenture"), between NORTHERN STATES POWER COMPANY, a 
corporation duly organized and existing under the laws of the State of 
Minnesota, having its principal office at 414 Nicollet Mall, Minneapolis, 
Minnesota 55401, (the "Company"), and NORWEST BANK MINNESOTA, NATIONAL 
ASSOCIATION, as trustee (the "Trustee").

    WHEREAS, the Company executed and delivered the indenture dated as of 
January 30, 1997 (the "Indenture"), to the Trustee to provide for the 
future issuance of the Company's unsecured debentures, notes or other 
evidence of indebtedness (the "Securities"), to be issued from time to time 
in one or more series as might be determined by the Company under the 
Indenture;

    WHEREAS, pursuant to the terms of the Indenture, the Company desires to 
provide for the establishment of a new series of its Securities to be known 
as its 7-7/8% Junior Subordinated Debentures due 2037 (the 
"Debentures"), the form and substance of such Debentures and the terms, 
provisions and conditions thereof to be set forth as provided in the 
Indenture and this First Supplemental Indenture;

    WHEREAS, NSP Financing I, a Delaware statutory business trust (the 
"Trust"), has offered to the public $200 million aggregate liquidation 
amount of its 7-7/8% Trust Originated Preferred Securities (the "Preferred 
Securities"), representing undivided beneficial interests in the assets of 
the Trust and proposes to invest the proceeds from such offering, together 
with the proceeds of the issuance and sale by the Trust to the Company of 
$6.19 million aggregate liquidation amount of its 7-7/8% Trust Originated 
Common Securities, in $206.19 million aggregate principal amount of the 
Debentures; and

    WHEREAS, the Company has requested that the Trustee execute and deliver 
this First Supplemental Indenture and all requirements necessary to make this 
First Supplemental Indenture a valid instrument in accordance with its terms, 
and to make the Debentures, when executed by the Company and authenticated 
and delivered by the Trustee, the valid obligations of the Company, have been 
performed, and the execution and delivery of this First Supplemental 
Indenture has been duly authorized in all respects:

    NOW THEREFORE, in consideration of the purchase and acceptance of the 
Debentures by the Holders thereof, and for the purpose of setting forth, as 
provided in the Indenture, the form and substance of the Debentures and the 
terms, provisions and conditions thereof, the Company covenants and agrees 
with the Trustee as follows: 






                                      ARTICLE I
                                     DEFINITIONS

SECTION 1.1. Definition of Terms.

    Unless the context otherwise requires:


    (a)  a term defined in the Indenture has the same meaning when used in this
First Supplemental Indenture;

    (b)  a term defined anywhere in this First Supplemental Indenture has the
same meaning throughout;

    (c)  the singular includes the plural and vice versa;

    (d)  headings are for convenience of reference only and do not affect
interpretation;

    (e)  the following terms have the meanings given to them in the 
Declaration:  (i) Business Day; (ii) Clearing Agency; (iii) Delaware Trustee; 
(iv) Depositary; (v) Dissolution Tax Opinion; (vi) No Recognition Opinion; 
(vii) Preferred Security Certificate; (viii) Institutional Trustee; (ix) 
Regular Trustees; (x) Special Event; (xi) Tax Event; (xii) Investment Company 
Event; and (xiii) Purchase Agreement;

    (f)  the following terms have the meanings given to them in this Section 
1.1(f):

    "Additional Interest" shall have the meaning set forth in Section 2.5.

    "Compounded Interest" shall have the meaning set forth in Section 4.1.

    "Declaration" means the Amended and Restated Declaration of Trust of NSP 
Financing I, a Delaware statutory business trust, dated as of January 31, 
1997. 

    "Deferred Interest" shall have the meaning set forth in Section 4.1.

    "Dissolution Event" means that, as a result of the occurrence and 
continuation of a Special Event, the Trust is to be dissolved in accordance 
with the Declaration, and the Debentures held by the Institutional Trustee 
are to be distributed to the holders of the Trust Securities issued by the 
Trust pro rata in accordance with the Declaration.

    "Extended Interest Payment Period" shall have the meaning set forth in 
Section 4.1.

    "Global Debenture" shall have the meaning set forth in Section 2.4.


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    "Maturity Date" means the date on which the Debentures mature and on 
which the principal shall be due and payable together with all accrued and 
unpaid interest thereon including Compounded Interest and Additional 
Interest, if any.

    "Non Book-Entry Preferred Securities" shall have the meaning set forth in 
Section 2.4.

    "Optional Redemption Price" shall have the meaning set forth in Section 
3.2.

                                  ARTICLE II
                 GENERAL TERMS AND CONDITIONS OF THE DEBENTURES

SECTION 2.1.  Designation and Principal Amount.

    There is hereby authorized a series of Securities designated the "7-7/8% 
Junior Subordinated Debentures due 2037", limited in aggregate principal 
amount to $206.19 million (the "Debentures"), which amount shall be as set 
forth in any written order of the Company for the authentication and delivery 
of Debentures pursuant to Section 303 of the Indenture.

SECTION 2.2.  Maturity.  The Maturity Date will be January 31, 2037.

SECTION 2.3.  Form and Payment.

    Except as provided in Section 2.4, the Debentures shall be issued in 
fully registered certificated form without interest coupons in denominations 
of $25 and any integral multiple thereof.  Principal and interest on the 
Debentures issued in certificated form will be payable, the transfer of such 
Debentures will be registrable and such Debentures will be exchangeable for 
Debentures bearing identical terms and provisions at the office or agency of 
the Trustee; provided, however, that payment of interest may be made at the 
option of the Company by check mailed to the Holder at such address as shall 
appear in the Security Register.  Notwithstanding the foregoing, so long as 
the Holder of any Debentures is the Institutional Trustee, the payment of the 
principal of and interest (including Compounded Interest and Additional 
Interest, if any) on such Debentures held by the Institutional Trustee will 
be made at such place and to such account as may be designated by the 
Institutional Trustee.

    Section 205 of the Indenture is hereby amended to read in its entirety as 
provided in the following Section 2.4:

SECTION 2.4.  Global Debenture.

    (a)  In connection with a Dissolution Event,

    (i)  the Debentures in certificated form may be presented to the Trustee 
by the Institutional Trustee in exchange for a global Debenture in an 
aggregate principal amount equal to the aggregate principal amount of all 
outstanding Debentures (a "Global Debenture"), to be registered in the name 
of the Depositary, or its nominee, and delivered by the Trustee to the 
Depositary for crediting to the accounts of its participants pursuant to the 
instructions of the 


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Regular Trustees.  The Company upon any such presentation shall execute a 
Global Debenture in such aggregate principal amount and deliver the same to 
the Trustee for authentication and delivery in accordance with the Indenture 
and this First Supplemental Indenture.  Payments on the Debentures issued as 
a Global Debenture will be made to the Depositary; and

    (ii) if any Preferred Securities are held in non book-entry certificated 
form, the Debentures in certificated form may be presented to the Trustee by 
the Institutional Trustee and any Preferred Security Certificate which 
represents Preferred Securities other than Preferred Securities held by the 
Clearing Agency or its nominee ("Non Book-Entry Preferred Securities") will 
be deemed to represent beneficial interests in Debentures presented to the 
Trustee by the Institutional Trustee having an aggregate principal amount 
equal to the aggregate liquidation amount of the Non Book-Entry Preferred 
Securities until such Preferred Security Certificates are presented to the 
Security Registrar for transfer or reissuance at which time such Preferred 
Security Certificates will be cancelled and a Debenture, registered in the 
name of the holder of the Preferred Security Certificate or the transferee of 
the holder of such Preferred Security Certificate, as the case may be, with 
an aggregate principal amount equal to the aggregate liquidation amount of 
the Preferred Security Certificate cancelled, will be executed by the Company 
and delivered to the Trustee for authentication and delivery in accordance 
with the Indenture and this First Supplemental Indenture.  On issue of such 
Debentures, Debentures with an equivalent aggregate principal amount that 
were presented by the Institutional Trustee to the Trustee will be deemed to 
have been cancelled.

    (b)  Unless and until it is exchanged for the Debentures in registered 
form, a Global Debenture may be transferred, in whole but not in part, only 
to another nominee of the Depositary, or to a successor Depositary selected 
or approved by the Company or to a nominee of such successor Depositary.

    (c)  If at any time the Depositary notifies the Company that it is 
unwilling or unable to continue as Depositary or if at any time the 
Depositary for such series shall no longer be registered or in good standing 
under the Securities Exchange Act of 1934, as amended, or other applicable 
statute or regulation, and a successor Depositary for such series is not 
appointed by the Company within 90 days after the Company receives such 
notice or becomes aware of such condition, as the case may be, the Company 
will execute, and, subject to Article III of the Indenture, the Trustee, upon 
written notice from the Company, will authenticate and deliver the Debentures 
in definitive registered form without coupons, in authorized denominations, 
and in an aggregate principal amount equal to the principal amount of the 
Global Debenture in exchange for such Global Debenture.  In addition, the 
Company may at any time determine that the Debentures shall no longer be 
represented by a Global Debenture.  In such event the Company will execute, and 
subject to Section 301 of the Indenture, the Trustee, upon receipt of an 
Officer's Certificate evidencing such determination by the Company, will 
authenticate and deliver the Debentures in definitive registered form without 
coupons, in authorized denominations, and in an aggregate principal amount 
equal to the principal amount of the Global Debenture in exchange for such 
Global Debenture.  Upon the exchange of the Global Debenture for such 
Debentures in definitive registered form without coupons, in authorized 
denominations, the Global Debenture shall be cancelled by the Trustee.  Such 
Debentures in definitive registered form issued in 


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exchange for the Global Debenture shall be registered in such names and in 
such authorized denominations as the Depositary, pursuant to instructions 
from its direct or indirect participants or otherwise, shall instruct the 
Trustee.  The Trustee shall deliver such Securities to the Depositary for 
delivery to the Persons in whose names such Securities are so registered.

SECTION 2.5.  Interest.

    (a)  Each Debenture will bear interest at the rate of 7-7/8% per annum 
(the "Coupon Rate") from the original date of issuance until the principal 
thereof becomes due and payable, and on any overdue principal and (to the 
extent that payment of such interest is enforceable under applicable law) on 
any overdue installment of interest at the Coupon Rate, compounded quarterly, 
payable (subject to the provisions of Article IV) quarterly in arrears on 
March 31, June 30, September 30 and December 31 of each year (each, an 
"Interest Payment Date") commencing on March 31, 1997, to the Person 
in whose name such Debenture or any predecessor Debenture is registered, at 
the close of business on the regular record date for such interest 
installment, which, in respect of (i) Debentures of which the Institutional 
Trustee is the Holder and the Preferred Securities are in book-entry only 
form or (ii) a Global Debenture, shall be the close of business on the 
Business Day next preceding that Interest Payment Date.  Notwithstanding the 
foregoing sentence, if (i) the Debentures are held by the Institutional 
Trustee and the Preferred Securities are no longer in book-entry only form or 
(ii) the Debentures are not represented by a Global Debenture, the Company 
may select a regular record date for such interest installment which shall be 
any date at least one Business Day but less than 60 Business Days before an 
Interest Payment Date.

    (b)  The amount of interest payable for any period will be computed on 
the basis of a 360-day year of twelve 30-day months.  Except as provided in 
the following sentence, the amount of interest payable for any period shorter 
than a full quarterly period for which interest is computed, will be computed 
on the basis of the actual number of days elapsed in such a 90-day period.  
In the event that any date on which interest is payable on the Debentures is 
not a Business Day, then payment of interest payable on such date will be 
made on the next succeeding day which is a Business Day (and without any 
interest or other payment in respect of any such delay), except that, if such 
Business Day is in the next succeeding calendar year, such payment shall be 
made on the immediately preceding Business Day, in each case with the same 
force and effect as if made on such date.

    (c)  If, at any time while the Institutional Trustee is the Holder of any 
Debentures, the Trust or the Institutional Trustee is required to pay any 
taxes, duties, assessments or governmental charges of whatever nature (other 
than withholding taxes) imposed by the United States, or any other taxing 
authority, then, in any case, the Company will pay as additional interest 
("Additional Interest") on the Debentures held by the Institutional Trustee, 
such additional amounts as shall be required so that the net amounts received 
and retained by the Trust and the Institutional Trustee after paying such 
taxes, duties, assessments or other governmental charges will be equal to the 
amounts the Trust and the Institutional Trustee would have received had no 
such taxes, duties, assessments or other government charges been imposed.

SECTION 2.6.  Preferred Security Holders Rights.

    If an Event of Default constituting the failure to pay interest or 
principal on the Debentures on the date such interest or principal is 
otherwise payable has occurred and is continuing, then a holder of Preferred 
Securities may directly institute a proceeding for enforcement of payment to 
such holder directly of the principal of or interest on the Debentures having 
a principal amount equal to the aggregate liquidation amount of the Preferred 
Securities or such holder on or after the respective due date specified in 
the Debentures. The holders of Preferred Securities will not be able to 
exercise directly any other remedy available to the holders of the Debentures 
under this First Supplemental Indenture or under the Indenture unless the 
Institutional Trustee fails to do so.


                                      5



                                 ARTICLE III.
                         REDEMPTION OF THE DEBENTURES

SECTION 3.1.  Tax Event Redemption.

    If a Tax Event has occurred and is continuing and:

    (a)  the Company has received a Redemption Tax Opinion; or

    (b)  after receiving a Dissolution Tax Opinion, the Regular Trustees 
shall have been informed by tax counsel rendering the Dissolution Tax Opinion 
that a No Recognition Opinion cannot be delivered to the Trust; then, 
notwithstanding Section 3.2(a) but subject to Section 3.2(b), the Company 
shall have the right upon not less than 30 days nor more than 60 days notice 
to the Holders of the Debentures to redeem the Debentures, in whole or in 
part, for cash within 90 days following the occurrence of such Tax Event (the 
"90 Day Period") at a redemption price equal to 100% of the principal amount 
to be redeemed plus any accrued and unpaid interest thereon to the date of 
such redemption (the "Redemption Price"), provided that if at the time there 
is available to the Company the opportunity to eliminate, within the 90 Day 
Period, the Tax Event by taking some ministerial action ("Ministerial 
Action"), such as filing a form or making an election, or pursuing some other 
similar reasonable measure which has no adverse effect on the Company, the 
Trust or the Holders of the Trust Securities issued by the Trust, the Company 
shall pursue such Ministerial Action in lieu of redemption, and, provided, 
further, that the Company shall have no right to redeem the Debentures while 
the Trust is pursuing any Ministerial Action pursuant to its obligations 
under the Declaration.  The Redemption Price shall be paid prior to 12:00 
noon, New York time, on the date of such redemption or such earlier time as 
the Company determines, provided that the Company shall deposit with the 
Trustee an amount sufficient to pay the Redemption Price by 10:00 a.m., New 
York time, on the date such Redemption Price is to be paid.

SECTION 3.2.  Optional Redemption by Company.

    (a)  Subject to the provisions of Section 3.2(b) and to the provisions of 
Article Eleven of the Indenture, except as otherwise may be specified in this 
First Supplemental Indenture, the Company shall have the right to redeem the 
Debentures, in whole or in part, from time to time, on or after January 31, 
2002, at a redemption price equal to 100% of the principal amount to be 
redeemed plus any accrued and unpaid interest thereon to the date of such 
redemption (the "Optional Redemption Price").  Any redemption pursuant to 
this paragraph will be made upon not less than 30 days nor more than 60 days 
notice to the Holder of the Debentures, at the Optional Redemption Price.  If 
the Debentures are only partially redeemed pursuant to this Section 3.2, the 
Debentures will be redeemed pro rata or by lot or by any other method 
utilized by the Trustee; provided, that if at the time of redemption the 
Debentures are registered as a Global Debenture, the Depositary shall 
determine, in accordance with its procedures, the 

                                      6



principal amount of such Debentures held by each Holder of Debentures to be 
redeemed.  The Optional Redemption Price shall be paid prior to 12:00 noon, 
New York time, on the date of such redemption or at such earlier time as the 
Company determines provided that the Company shall deposit with the Trustee 
an amount sufficient to pay the Optional Redemption Price by 10:00 a.m., New 
York time, on the date such Optional Redemption Price is to be paid.

    (b)  If a partial redemption of the Debentures would result in the 
delisting of the Preferred Securities issued by the Trust from any national 
securities exchange or other organization on which the Preferred Securities 
are then listed, the Company shall not be permitted to effect such partial 
redemption and may only redeem the Debentures in whole.

SECTION 3.3.  No Sinking Fund.

    The Debentures are not entitled to the benefit of any sinking fund.

                                  ARTICLE IV
                    EXTENSION OF INTEREST PAYMENT PERIOD

SECTION 4.1.  Extension of Interest Payment Period.

    The Company shall have the right, at any time and from time to time 
during the term of the Debentures, to defer payments of interest by extending 
the interest payment period of such Debentures for a period not exceeding 20 
consecutive quarters (the "Extended Interest Payment Period"), during which 
Extended Interest Payment Period no interest shall be due and payable; 
provided that no Extended Interest Payment Period may extend beyond the 
Maturity Date. To the extent permitted by applicable law, interest, the 
payment of which has been deferred because of the extension of the interest 
payment period pursuant to this Section 4.1, will bear interest thereon at 
the Coupon Rate compounded quarterly for each quarter of the Extended 
Interest Payment Period ("Compounded Interest").  At the end of the Extended 
Interest Payment Period, the Company shall pay all interest accrued and 
unpaid on the Debentures, including any Additional Interest and Compounded 
Interest (together, "Deferred Interest") that shall be payable to the Holders 
of the Debentures in whose names the Debentures are registered in the 
Security Register on the first record date after the end of the Extended 
Interest Payment Period.  Before the termination of any Extended Interest 
Payment Period, the Company may further extend such period, provided that 
such period together with all such further extensions thereof shall not 
exceed 20 consecutive quarters, or extend beyond the maturity date of the 
Debentures.  Upon the termination of any Extended Interest Payment Period and 
upon the payment of all Deferred Interest then due, the Company may commence 
a new Extended Interest Payment Period, subject to the foregoing 
requirements.  No interest shall be due and payable during an Extended 
Interest Payment Period, except at the end thereof, but the Company may 
prepay at any time all or any portion of the interest accrued during an 
Extended Interest Payment Period.


                                      7



SECTION 4.2.  Notice of Extension.

    (a)  If the Institutional Trustee is the only registered Holder of the 
Debentures at the time the Company selects an Extended Interest Payment 
Period, the Company shall give written notice to the Regular Trustees, the 
Institutional Trustee and the Trustee of its selection of such Extended 
Interest Payment Period one Business Day before the earlier of (i) the next 
succeeding date on which Distributions on the Trust Securities issued by the 
Trust are payable, or (ii) the date the Trust is required to give notice of 
the record date, or the date such Distributions are payable, to the New York 
Stock Exchange or other applicable self-regulatory organization or to holders 
of the Preferred Securities issued by the Trust, but in any event at least 
one Business Day before such record date.

    (b)  If the Institutional Trustee is not the only Holder of the 
Debentures at the time the Company selects an Extended Interest Payment 
Period, the Company shall give the Holders of the Debentures and the Trustee 
written notice of its selection of such Extended Interest Payment Period at 
least 10 Business Days before the earlier of (i) the next succeeding Interest 
Payment Date, or (ii) the date the Company is required to give notice of the 
record or payment date of such interest payment to the New York Stock 
Exchange or other applicable self-regulatory organization or to Holders of 
the Debentures.

    (c)  The quarter in which any notice is given pursuant to paragraphs (a) 
or (b) of this Section 4.2 shall be counted as one of the 20 quarters 
permitted in the maximum Extended Interest Payment Period permitted under 
Section 4.1.

SECTION 4.3.  Limitation of Transactions.

    If (i) the Company shall exercise its right to defer payment of interest 
as provided in Section 4.1, or (ii) there shall have occurred any Event of 
Default, as defined in the Indenture, then (a) the Company shall not declare 
or pay any dividend on, make any distributions with respect to, or redeem, 
purchase, acquire or make a liquidation payment with respect to, any of its 
capital stock (other than (i) purchases or acquisitions of shares of its 
common stock in connection with the satisfaction by the Company of its 
obligations under any employee benefit plans or the satisfaction by the 
Company of its obligations pursuant to any contract or security requiring the 
Company to purchase shares of its common stock, (ii) as a result of a 
reclassification of its capital stock or the exchange or conversion of one 
class or series of its capital stock for another class or series of its 
capital stock or, (iii) the purchase of fractional interests in shares of its 
capital stock pursuant to the conversion or exchange provisions of such 
capital stock or security being converted or exchanged) or make any guarantee 
payment with respect thereto, (b) the Company shall not make any payment of 
interest, principal or premium, if any, on or repay, repurchase or redeem any 
debt securities issued by the Company which rank pari passu with or junior to 
the Debentures and the Company shall not make any guarantee payments with 
respect to the foregoing (other than pursuant to the Preferred Security 
Guaranty).


                                      8



                                  ARTICLE V.
                                  EXPENSES

SECTION 5.1.  Payment of Expenses.

    In connection with the offering, sale and issuance of the Debentures to 
the Institutional Trustee and in connection with the sale of the Trust 
Securities by the Trust, the Company, in its capacity as borrower with 
respect to the Debentures, shall:

    (a)  pay all costs and expenses relating to the offering, sale and 
issuance of the Debentures, including commissions to the underwriters payable 
pursuant to the Purchase Agreement and compensation of the Trustee under 
the Indenture in accordance with the provisions of Section 607 of the 
Indenture;

    (b)  pay all costs and expenses of the Trust (including, but not limited 
to, costs and expenses relating to the organization of the Trust, the 
offering, sale and issuance of the Trust Securities (including commissions to 
the underwriters in connection therewith), the fees and expenses of the 
Institutional Trustee and the Delaware Trustee, the costs and expenses 
relating to the operation of the Trust, including without limitation, costs 
and expenses of accountants, attorneys, statistical or bookkeeping services, 
expenses for printing and engraving and computing or accounting equipment, 
paying agent(s), registrar(s), transfer agent(s), duplicating, travel and 
telephone and other telecommunications expenses and costs and expenses 
incurred in connection with the acquisition, financing, and disposition of 
Trust assets);

    (c)  be primarily liable for any indemnification obligations arising with 
respect to the Declaration; and 

    (d)  pay any and all taxes (other than United States withholding taxes 
attributable to the Trust or its assets) and all liabilities, costs and 
expenses with respect to such taxes of the Trust.

SECTION 5.2.  Payment Upon Resignation or Removal.

    Upon termination of this First Supplemental Indenture or the Indenture or 
the removal or resignation of the Trustee pursuant to this Section 5.2, the 
Company shall pay to the Trustee all amounts accrued to the date of such 
termination, removal or resignation.  Upon termination of the Declaration or 
the removal or resignation of the Delaware Trustee or the Institutional 
Trustee, as the case may be, pursuant to Section 5.6 of the Declaration, the 
Company shall pay to the Delaware Trustee or the Institutional Trustee, as 
the case may be, all amounts accrued to the date of such termination, removal 
or resignation.


                                      9



                                  ARTICLE VI
                                    NOTICE

SECTION 6.1.  Notice by the Company.

    The Company shall give prompt written notice to a Responsible Officer of 
the Trustee of any fact known to the Company that would prohibit the making 
of any payment of monies to or by the Trustee in respect of the Debentures 
pursuant to the provisions of this Article VI.  Notwithstanding the 
provisions of this Article VI or any other provision of the Indenture and 
this First Supplemental Indenture, the Trustee shall not be charged with 
knowledge of the existence of any facts that would prohibit the making of any 
payment of monies to or by the Trustee in respect of the Debentures pursuant 
to the provisions of this Article VI, unless and until a Responsible Officer 
of the Trustee shall have received written notice thereof from the Company or 
a holder or holders of Senior Indebtedness or from any trustee therefor; and 
before the receipt of any such written notice, the Trustee, subject to the 
provisions of Section 601 of the Indenture, shall be entitled in all respects 
to assume that no such facts exist; provided, however, that if the Trustee 
shall not have received the notice provided for in this Section 6.1 at least 
two Business Days prior to the date upon which by the terms hereof any money 
may become payable for any purpose (including, without limitation, the 
payment of the principal of (or premium, if any) or interest on any 
Debenture), then, anything herein contained to the contrary notwithstanding, 
the Trustee shall have full power and authority to receive such money and to 
apply the same to the purposes for which they were received, and shall not be 
affected by any notice to the contrary that may be received by it within two 
Business Days prior to such date.

    The Trustee, subject to the provisions of Section 601 of the Indenture, 
shall be entitled to conclusively rely on the delivery to it of a written 
notice by a Person representing himself to be a holder of Senior Indebtedness 
of the Company, as the case may be (or a trustee on behalf of such holder), 
to establish that such notice has been given by a holder of such Senior 
Indebtedness or a trustee on behalf of any such holder or holders.  In the 
event that the Trustee determines in good faith that further evidence is 
required with respect to the right of any Person as a holder of such Senior 
Indebtedness to participate in any payment or distribution pursuant to this 
Article VI, the Trustee may request such Person to furnish evidence to the 
reasonable satisfaction of the Trustee as to the amount of such Senior 
Indebtedness held by such Person, the extent to which such Person is entitled 
to participate in such payment or distribution and any other facts pertinent 
to the rights of such Person under this Article VI, and, if such evidence is 
not furnished, the Trustee may defer any payment to such Person pending 
judicial determination as to the right of such Person to receive such payment.

                                 ARTICLE VII.
                         COVENANT TO LIST ON EXCHANGE

SECTION 7.1.  Listing on an Exchange.

    If the Debentures are to be issued as a Global Debenture in connection 
with the distribution of the Debentures to the holders of the Preferred 
Securities issued by the Trust upon 


                                      10



a Dissolution Event, the Company will use its best efforts to list such 
Debentures on the New York Stock Exchange, Inc. or on such other exchange as 
the Preferred Securities are then listed.

                                 ARTICLE VIII.
                               FORM OF DEBENTURE

SECTION 8.1.  Form of Debenture.

    The Debentures and the Trustee's Certificate of Authentication to be 
endorsed thereon are to be substantially in the following forms:

                           (FORM OF FACE OF DEBENTURE)

    [IF THE DEBENTURE IS TO BE A GLOBAL DEBENTURE, INSERT - This Debenture is a
Global Debenture within the meaning of the Indenture hereinafter referred to and
is registered in the name of a Depositary or a nominee of a Depositary.  This
Debenture is exchangeable for Debentures registered in the name of a person
other than the Depositary or its nominee only in the limited circumstances
described in the Indenture, and no transfer of this Debenture (other than a
transfer of this Debenture as a whole by the Depositary to a nominee of the
Depositary or by a nominee of the Depositary to the Depositary or another
nominee of the Depositary) may be registered except in limited circumstances.

    Unless this Debenture is presented by an authorized representative of The
Depository Trust Company (55 Water Street, New York, New York) to the issuer or
its agent for registration of transfer, exchange or payment, and any Debenture
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
hereon is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
OR OTHERWISE BY A PERSON IS WRONGFUL since the registered owner hereof, Cede &
Co., has an interest herein.]


No.
   --------------------------
$
 ----------------------------
CUSIP No.
         --------------------

                         NORTHERN STATES POWER COMPANY

                      7-7/8% JUNIOR SUBORDINATED DEBENTURE
                                    DUE 2037

    NORTHERN STATES POWER COMPANY, a Minnesota corporation (the "Company", 
which term includes any successor corporation under the Indenture hereinafter 
referred to), for value received, hereby promises to pay to ______________, 
or registered assigns, the principal sum of ______________ Dollars 
($_________) on January 31, 2037, and to pay interest on said 
principal sum from January 31, 1997, or from the most recent interest 
payment date (each such date, an "Interest Payment Date") to which interest 
has been paid or 


                                      11



duly provided for, quarterly (subject to deferral as set forth herein) in 
arrears on March 31, June 30, September 30 and December 31 of each year 
commencing March 31, 1997, at the rate of 7-7/8% per annum until the 
principal hereof shall have become due and payable, and on any overdue 
principal and premium, if any, and (without duplication and to the extent 
that payment of such interest is enforceable under applicable law) on any 
overdue installment of interest at the same rate per annum compounded 
quarterly.  The amount of interest payable on any Interest Payment Date shall 
be computed on the basis of a 360-day year of twelve 30-day months.  In the 
event that any date on which interest is payable on this Debenture is not a 
Business Day, then payment of interest payable on such date will be made on 
the next succeeding day that is a Business Day (and without any interest or 
other payment in respect of any such delay), except that, if such Business 
Day is in the next succeeding calendar year, such payment shall be made on 
the immediately preceding Business Day, in each case with the same force and 
effect as if made on such date.  The interest installment so payable, and 
punctually paid or duly provided for, on any Interest Payment Date will, as 
provided in the Indenture, be paid to the person in whose name this Debenture 
(or one or more Predecessor Securities, as defined in said Indenture) is 
registered at the close of business on the regular record date for such 
interest installment, which shall be the close of business on the business 
day next preceding such Interest Payment Date. [IF PURSUANT TO THE PROVISIONS 
OF THE INDENTURE THE DEBENTURES ARE NO LONGER REPRESENTED BY A GLOBAL 
DEBENTURE--which shall be the close of business on the fifteenth day 
next preceding such Interest Payment Date.] Any such interest installment not 
punctually paid or duly provided for shall forthwith cease to be payable to 
the registered Holders on such regular record date and may be paid to the 
Person in whose name this Debenture (or one or more Predecessor Securities) is 
registered at the close of business on a special record date to be fixed by 
the Trustee for the payment of such defaulted interest, notice whereof shall 
be given to the registered Holders of this series of Debentures 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 Debentures may be listed, and upon such notice as may be 
required by such exchange, all as more fully provided in the Indenture.  The 
principal of (and premium, if any) and the interest on this Debenture shall be 
payable at the office or agency of the Trustee maintained for that purpose in 
any coin or currency of the United States of America that at the time of 
payment is legal tender for payment of public and private debts; provided, 
however, that payment of interest may be made at the option of the Company by 
check mailed to the registered Holder at such address as shall appear in the 
Security Register. Notwithstanding the foregoing, so long as the Holder of this 
Debenture is the Institutional Trustee, the payment of the principal of (and 
premium, if any) and interest on this Debenture will be made at such place 
and to such account as may be designated by the Institutional Trustee.

    The indebtedness evidenced by this Debenture is, to the extent provided 
in the Indenture, subordinate and junior in right of payment to the prior 
payment in full of all Senior Indebtedness, and this Debenture is issued 
subject to the provisions of the Indenture with respect thereto.  Each Holder 
of this Debenture, by accepting the same, (a) agrees to and shall be bound by 
such provisions, (b) authorizes and directs the Trustee on his or her behalf 
to take such action as may be necessary or appropriate to acknowledge or 
effectuate the subordination so provided and (c) appoints the Trustee his or 
her attorney-in-fact for any and all such purposes.  Each Holder 


                                      12



hereof, by his or her acceptance hereof, hereby waives all notice of the 
acceptance of the subordination provisions contained herein and in the 
Indenture by each holder of Senior Indebtedness, whether now outstanding or 
hereafter incurred, and waives reliance by each such holder upon said 
provisions.

    This Debenture shall not be entitled to any benefit under the Indenture 
hereinafter referred to, be valid or become obligatory for any purpose until 
the Certificate of Authentication hereon shall have been signed by or on 
behalf of the Trustee.

    The provisions of this Debenture are continued on the reverse side hereof 
and such continued provisions shall for all purposes have the same effect as 
though fully set forth at this place.

    IN WITNESS WHEREOF, the Company has caused thiS instrument to be executed.



Dated:
      ---------------------------

                                       NORTHERN STATES POWER COMPANY


                                       By:
                                          -------------------------------------
                                       Name:
                                       Title:



Attest:


By:
   ------------------------------
Name:
Title:


                       (FORM OF CERTIFICATE OF AUTHENTICATION)

                            CERTIFICATE OF AUTHENTICATION

    This is one of the Debentures of the series of Debentures described in 
the within-mentioned Indenture.


     By:                                By:
        -------------------------          ------------------------------------
         as Trustee                         as Authentication Agent


                                      13



                                      or

     By:                                By:
        -------------------------          ------------------------------------
        Authorized Signatory               Authorized Signatory










                                      14



                       (FORM OF REVERSE OF DEBENTURE)

    This Debenture is one of a duly authorized series of Securities of the 
Company (herein sometimes referred to as the "Securities"), specified in the 
Indenture, all issued or to be issued in one or more series under and 
pursuant to an Indenture dated as of January 30, 1997, duly executed 
and delivered between the Company and Norwest Bank Minnesota, National 
Association as Trustee (the "Trustee"), as supplemented by the First 
Supplemented Indenture dated as of January 31, 1997, between the Company and 
the Trustee (the Indenture as so supplemented, the "Indenture"), to which 
Indenture and all indentures supplemental thereto reference is hereby made 
for a description of the rights, limitations of rights, obligations, duties 
and immunities thereunder of the Trustee, the Company and the Holders of the 
Securities.  By the terms of the Indenture, the Securities are issuable in 
series that may vary as to amount, date of maturity, rate of interest and in 
other respects as provided in the Indenture.  This series of Securities is 
limited in aggregate principal amount as specified in said First Supplemental 
Indenture.

    Except as provided in the next paragraph, the Debentures may not be 
redeemed by the Company prior to January 31, 2002. The Company shall 
have the right to redeem this Debenture at the option of the Company, without 
premium or penalty, in whole or in part at any time and from time to time on 
or after January 31, 2002 (an "Optional Redemption"), at a redemption 
price equal to 100% of the principal amount plus any accrued but unpaid 
interest, including any Compounded Interest, if any, to the date of such 
redemption (the "Optional Redemption Price").  Any redemption pursuant to 
this paragraph will be made upon not less than 30 nor more than 60 days' 
notice, at the Optional Redemption Price.

    If, at any time, a Tax Event (as defined below) shall occur or be 
continuing after receipt of a Dissolution Tax Opinion (as defined below) and 
either (i) the Regular Trustees and the Company shall have received an 
opinion (a "Redemption Tax Opinion") of a nationally recognized independent 
tax counsel experienced in such matters that, as a result of a Tax Event (as 
defined herein), there is more than an insubstantial risk that the Company 
would be precluded from deducting the interest on the Debentures for United 
States federal income tax purposes even after the Debentures were distributed 
to the holders of Preferred Securities and Common Securities in liquidation 
of such holder's interest in the Trust as set forth in the Declaration of 
Trust or (ii) the Regular Trustees shall have been informed by such tax 
counsel that a No Recognition Opinion (as defined below) cannot be delivered, 
the Company shall have the right at any time, upon not less than 30 nor more 
than 60 days' notice, to redeem the Debentures in whole or in part for cash 
at the Optional Redemption Price within 90 days following the occurrence of 
such Tax Event; provided, however, that, if at that time there is 
available to the Company or the Trust the opportunity to eliminate, within 
such 90 day period, the Tax Event by taking some ministerial action 
("Ministerial Action"), such as filing a form or making an election, or 
pursuing some other 

                                      15



similar reasonable measure, which has no adverse effect on the Trust, the 
Company or the Holders of the Preferred Securities, the Company or the Trust 
will pursue such measure in lieu of redemption and provided further that the 
Company shall have no right to redeem the Debentures while the Trust is 
pursuing any such Ministerial Action.

    "Tax Event" means that the Regular Trustees shall have received an 
opinion of a nationally recognized independent tax counsel experienced in 
such matters (a "Dissolution Tax Opinion") to the effect that, as a result of 
(a) any amendment to, or change (including any announced prospective change) 
in the laws (or any regulations thereunder) of the United States or any 
political subdivision or taxing authority thereof or therein or (b) any 
amendment to or interpretation or application of such laws or 
regulations by any legislative body, court, governmental agency or regulatory 
authority (including the enactment of any legislation and the publication of 
any judicial decision or regulatory determination on or after such date), 
there is more than an insubstantial risk that (i) the Trust would be subject 
to United States federal income tax with respect to income accrued or 
received on the Debentures, (ii) interest payable to the Trust on the 
Debentures would not be deductible by the Company for United States federal 
income tax purposes or (iii) the Trust would be subject to more than a de 
minimis amount of other taxes, duties or other governmental charges, which 
change or amendment becomes effective on or after January 28, 1997.

    Any redemption pursuant to the occurrence of a Tax Event will be made 
upon not less than 30 days nor more than 60 days notice, at the Optional 
Redemption Price.

    If the Debentures are only partially redeemed by the Company pursuant to 
an Optional Redemption, the Debentures will be redeemed pro rata or by lot or 
by any other method utilized by the Trustee; provided that if, at the time of 
redemption, the Debentures are registered as a Global Debenture, the 
Depositary shall determine the principal amount of such Debentures held by 
each Debentureholder to be redeemed in accordance with its procedures.

    In the event of redemption of this Debenture in part only, a new 
Debenture or Debentures of this series for the unredeemed portion hereof will 
be issued in the name of the Holder hereof upon the cancellation hereof.

    In case an Event of Default, as defined in the Indenture, shall have
occurred and be continuing, the principal of all of the Debentures may be
declared, and upon such declaration 


                                      16



shall become, due and payable, in the manner, with the effect and subject to 
the conditions provided in the Indenture.

    The Indenture contains provisions permitting the Company and the Trustee, 
with the consent of the Holders of not less than a majority in aggregate 
principal amount of the Debentures of each series affected at the time 
outstanding, as defined in the Indenture, to execute supplemental indentures 
for the purpose of adding any provisions to or changing in any manner or 
eliminating any of the provisions of the Indenture or of any supplemental 
indenture or of modifying in any manner the rights of the Holders of the 
Debentures; provided, however, that no such supplemental indenture shall (i) 
reduce the principal amount thereof, or reduce the rate or extend the time of 
payment of interest thereon, or reduce any premium payable upon the 
redemption thereof, without the consent of the Holder of each Debenture so 
affected, or (ii) reduce the aforesaid percentage of Debentures, the Holders 
of which are required to consent to any such supplemental indenture, without 
the consent of the Holders of each Debenture then outstanding and affected 
thereby.  The Indenture also contains provisions permitting the Holders of a 
majority in aggregate principal amount of the Securities of any series at the 
time outstanding affected thereby, on behalf of all of the Holders of the 
Debentures of such series, to waive any Default or Event of Default with 
respect to such series, and its consequences, except a Default or Event of 
Default in the payment of the principal of or premium, if any, or interest on 
any of the Securities of such series or in respect of a provision which under 
the Indenture cannot be modified or amended without the consent of the Holder 
of each Outstanding Security of that series affected.  Any such consent or 
waiver by the registered Holder of this Debenture (unless revoked as provided 
in the Indenture) shall be conclusive and binding upon such Holder and upon 
all future Holders and owners of this Debenture and of any Debenture issued 
in exchange herefor or in place hereof (whether by registration of transfer 
or otherwise), irrespective of whether or not any notation of such consent or 
waiver is made upon this Debenture.

    No reference herein to the Indenture and no provision of this Debenture 
or of the Indenture shall alter or impair the obligation of the Company, 
which is absolute and unconditional, to pay the principal of and premium, if 
any, and interest on this Debenture at the time and place and at the rate and 
in the money herein prescribed.

    So long as the Company is not in default in the payment of interest on 
the Debentures, the Company shall have the right at any time during the term 
of the Debentures from time to time to extend the interest payment period of 
such Debentures for up to 20 consecutive quarters (an "Extended Interest 
Payment Period"), at the end of which period the Company shall pay all 
interest then accrued and unpaid (together with the interest thereon at the 
rate specified for the Debentures to the extent that payment of such interest 
is enforceable under applicable law).  In the event that the Company 
exercises this right, then (a) the Company shall not declare or pay dividends 
on, make distributions with respect to, or redeem, purchase or acquire, or 
make a liquidation payment with respect to, any of its capital stock (other 
than (i) purchases or acquisitions of shares of its Common Stock in 
connection with the satisfaction by the Company of its obligations under any 
employee benefit plans or the satisfaction by the Company of its obligations 
pursuant to any contract or security requiring the Company to purchase shares 
of its Common Stock, (ii) as a result of a reclassification of the Company's 
capital stock or the 


                                      17



exchange or conversion of one class or series of the Company's capital stock 
for another class or series of the Company's capital stock or (iii) the 
purchase of fractional interests in shares of the Company's capital stock 
pursuant to the conversion or exchange provisions of such capital stock or 
the security being converted or exchanged) or make any guarantee payments 
with respect to the foregoing), (b) the Company shall not make any payment of 
interest, principal or premium, if any, on or repay, repurchase or redeem any 
debt securities (including guarantees) issued by the Company that rank pari 
passu with or junior to such Debentures and (c) the Company shall not make 
any guarantee payments with respect to the foregoing (other than pursuant to 
the Preferred Securities Guarantee).  Prior to the termination of any such 
Extended Interest Payment Period, the Company may further extend the interest 
payment period; provided, that such Extended Interest Payment Period, 
together with all such previous and further extensions thereof, may not 
exceed 20 consecutive quarters or extend beyond the maturity date of the 
Debentures.  At the termination of any such Extended Interest Payment Period 
and upon the payment of all accrued and unpaid interest and any additional 
amount then due, the Company may commence a new Extended Interest Payment 
Period, subject to the above requirements.

    As provided in the Indenture and subject to certain limitations therein 
set forth, this Debenture is transferable by the registered Holder hereof on 
the Security Register of the Company, upon surrender of this Debenture for 
registration of transfer at the office or agency of the Trustee in the City 
of Minneapolis and State of Minnesota accompanied by a written instrument or 
instruments of transfer in form satisfactory to the Company or the Trustee 
duly executed by the registered Holder hereof or his attorney duly authorized 
in writing, and thereupon one or more new Debentures of authorized 
denominations and for the same aggregate principal amount and series will be 
issued to the designated transferee or transferees.  No service charge will 
be made for any such transfer, but the Company may require payment of a sum 
sufficient to cover any tax or other governmental charge payable in relation 
thereto.

    Prior to due presentment for registration of transfer of this Debenture, 
the Company, the Trustee, any paying agent and the Security Registrar may 
deem and treat the registered Holder hereof as the absolute owner hereof 
(whether or not this Debenture shall be overdue and notwithstanding any 
notice of ownership or writing hereon made by anyone other than the Security 
Registrar) for the purpose of receiving payment of or on account of the 
principal hereof and premium, if any, and interest due hereon and for all 
other purposes, and neither the Company nor the Trustee nor any paying agent 
nor any Security Registrar shall be affected by any notice to the contrary.

    No recourse shall be had for the payment of the principal of or the 
interest on this Debenture, or for any claim based hereon, or otherwise in 
respect hereof, or based on or in respect of the Indenture, against any 
incorporator, stockholder, officer or director, past, present or future, as 
such, of the Company or of any predecessor or successor corporation, 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 issuance hereof, 
expressly waived and released.


                                      18



    The Indenture imposes certain limitations on the ability of the Company 
to, among other things, merge or consolidate with any other Person or sell, 
assign, transfer or lease all or substantially all of its properties or 
assets.  [If other covenants are applicable pursuant to the provisions of 
Section 301, insert here].  All such covenants and limitations are subject to 
a number of important qualifications and exceptions.  The Company must report 
periodically to the Trustee on compliance with the covenants in the Indenture.

    [The Debentures of this series are issuable only in registered form without
coupons in denominations of $25 and any integral multiple thereof.] [This Global
Debenture is exchangeable for Debentures in definitive form only under certain
limited circumstances set forth in the Indenture.  Debentures of this series so
issued are issuable only in registered form without coupons in denominations of
$25 and any integral multiple thereof.] As provided in the Indenture and subject
to certain limitations [herein and] therein set forth, Debentures of this series
(so issued) are exchangeable for a like aggregate principal amount of Debentures
of this series of a different authorized denomination, as requested by the
Holder surrendering the same.

    All terms used in this Debenture that are defined in the Indenture shall
have the meanings assigned to them in the Indenture.


























                                      19



                                  ARTICLE IX.
                        ORIGINAL ISSUE OF DEBENTURES

SECTION 9.1.  Original Issue of Debentures.

    Debentures in the aggregate principal amount of $ 206,190,000 may, upon 
execution of this First Supplemental Indenture, be executed by the Company 
and delivered to the Trustee for authentication, and the Trustee shall 
thereupon authenticate and deliver said Debentures to or upon the written 
order of the Company, signed by its Chairman, its President, or any Vice 
President and its Treasurer or an Assistant Treasurer, without any further 
action by the Company.

                                  ARTICLE X.
                                MISCELLANEOUS

SECTION 10.1.  Ratification of Indenture.

    The Indenture, as supplemented by this First Supplemental Indenture, is 
in all respects ratified and confirmed, and this First Supplemental Indenture 
shall be deemed part of the Indenture in the manner and to the extent herein 
and therein provided.

SECTION 10.2.  Trustee Not Responsible for Recitals.

    The recitals herein contained are made by the Company and not by the 
Trustee, and the Trustee assumes no responsibility for the correctness 
thereof. The Trustee makes no representation as to the validity or 
sufficiency of this First Supplemental Indenture.

SECTION 10.3.  Governing Law.

    This First Supplemental Indenture and each Debenture shall be deemed to 
be a contract made under the internal laws of the State of Minnesota, and for 
all purposes shall be construed in accordance with the laws of said State.

SECTION 10.4.  Separability.

    In case any one or more of the provisions contained in this First 
Supplemental Indenture or in the Debentures shall for any reason be held to 
be invalid, illegal or unenforceable in any respect, such invalidity, 
illegality or unenforceability shall not affect any other provisions of this 
First Supplemental Indenture or of the Debentures, but this First 
Supplemental Indenture and the Debentures shall be construed as if such 
invalid or illegal or unenforceable provision had never been contained herein 
or therein.


                                      20



SECTION 10.5.  Counterparts.

    This First Supplemental Indenture may be executed in any number of 
counterparts each of which shall be an original; but such counterparts shall 
together constitute but one and the same instrument.

    IN WITNESS WHEREOF, the parties hereto have caused this First 
Supplemental Indenture to be duly executed, and their respective corporate 
seals to be hereunto affixed and attested, on the date or dates indicated in 
the acknowledgments and as of the day and year first above written.

                                       NORTHERN STATES POWER COMPANY

                                       By: /s/ Edward J. McIntyre
                                          -------------------------------------
                                       Name:  Edward J. McIntyre
                                       Title: Vice President and Chief 
                                              Financial Officer

    [Seal]
    Attest:

    By: /s/ Gary R. Johnson
       -------------------------------
    Name:  Gary R. Johnson
    Title: Vice President,
           General Counsel and
           Corporate Secretary



                                       NORWEST BANK MINNESOTA,
                                       NATIONAL ASSOCIATION
                                       as Trustee

                                       By /s/ Raymond S. Haverstock
                                         --------------------------------------
                                       Name: Raymond S. Haverstock
                                       Title: Vice President










                                      21