Exhibit 99(a)
                                      
                              
                                                     
                                                                    

                       THE MONTANA POWER COMPANY


                                  TO


                     MORGAN GUARANTY TRUST COMPANY
                              OF NEW YORK

             (formerly Guaranty Trust Company of New York)


                                  AND


                             P.J. CROWLEY

            (successor to Arthur E. Burke, Karl R. Henrich,
                     H. H. Gould and R. Amundsen),


                     As Trustees under The Montana
                     Power Company's Mortgage and
                      Deed of Trust, dated as of
                            October 1, 1945


                                               

                  SEVENTEENTH SUPPLEMENTAL INDENTURE

                  Providing, among other things, for
              First Mortgage Bonds, 5.90% Series due 2023
                                               


                     Dated as of December 1, 1993
                                                                       
                                                                       




                  SEVENTEENTH SUPPLEMENTAL INDENTURE

                                      

           SEVENTEENTH SUPPLEMENTAL INDENTURE, dated as of
December 1, 1993, between THE MONTANA POWER COMPANY, a corpo-
ration of the State of Montana (successor by merger to The
Montana Power Company, a corporation of the State of New Jersey),
whose post office address is 40 East Broadway, Butte, Montana
59701 (hereinafter sometimes called the Company), and MORGAN
GUARANTY TRUST COMPANY OF NEW YORK, a corporation of the State of
New York (formerly Guaranty Trust Company of New York), whose
post office address is 60 Wall Street, New York, N.Y. 10260
(hereinafter sometimes called the Corporate Trustee) and P.J.
CROWLEY (successor to Arthur E. Burke, Karl R. Henrich, H. H.
Gould and R. Amundsen), whose post office address is 22 Wayne
Street, Montvale, N.J. 07645 (said P.J. Crowley being hereinafter
sometimes called the Co-Trustee, and the Corporate Trustee and
the Co-Trustee being hereinafter together sometimes called the
Trustees), as Trustees under the Mortgage and Deed of Trust,
dated as of October 1, 1945 (hereinafter called the Mortgage and,
together with any indentures supplemental thereto, hereinafter
sometimes called the Indenture), which Mortgage was executed and
delivered by The Montana Power Company, a corporation of the
State of New Jersey (hereinafter sometimes called the Company--
New Jersey) to Guaranty Trust Company of New York and Arthur E.
Burke, to secure the payment of bonds issued or to be issued
under and in accordance with the provisions of the Mortgage,
reference to which Mortgage is hereby made, this instrument
(hereinafter called the Seventeenth Supplemental Indenture) being
supplemental thereto;

           WHEREAS, the Mortgage was or is to be recorded in the
official records of various counties in the states of Montana and
Wyoming, which counties include or will include all counties in
which this Seventeenth Supplemental Indenture is to be recorded;
and

           WHEREAS, by the Mortgage, the Company--New Jersey
covenanted that it would execute and deliver such supplemental
indenture or indentures and such further instruments and do such
further acts as might be necessary or proper to carry out more
effectually the purposes of the Indenture and to make subject to
the lien of the Indenture any property thereafter acquired, made
or constructed and intended to be subject to the lien thereof;
and

           WHEREAS, the Company--New Jersey executed and delivered
to the Trustees its First Supplemental Indenture, dated as of May
1, 1954 (hereinafter called the First Supplemental Indenture);
its Second Supplemental Indenture, dated as of April 1, 1959
(hereinafter called the Second Supplemental Indenture); and

           WHEREAS, the Company--New Jersey was merged into the
Company on November 30, 1961, and to evidence the succession of
the Company to the Company--New Jersey and the assumption by the
Company of the covenants and conditions of the Company--New
Jersey in the bonds and in the Indenture contained and to enable
the Company to have and exercise the powers and rights of the
Company--New Jersey under the Indenture in accordance with the
terms thereof, the Company executed and delivered to the Trustees
its Third Supplemental Indenture, dated as of November 30, 1961
(hereinafter called the Third Supplemental Indenture); and

           WHEREAS, the Company executed and delivered to the
Trustees its Fourth Supplemental Indenture, dated as of April 1,
1970 (hereinafter called the Fourth Supplemental Indenture); its
Fifth Supplemental Indenture, dated as of April 1, 1971
(hereinafter called the Fifth Supplemental Indenture); its Sixth
Supplemental Indenture, dated as of March 1, 1974 (hereinafter
called the Sixth Supplemental Indenture); its Seventh
Supplemental Indenture, dated as of December 1, 1974 (hereinafter
called the Seventh Supplemental Indenture); its Eighth
Supplemental Indenture, dated as of July 1, 1975 (hereinafter
called the Eighth Supplemental Indenture);  its Ninth Supplement-
al Indenture, dated as of December 1, 1975 (hereinafter called
the Ninth Supplemental Indenture); its Tenth Supplemental
Indenture, dated as of January 1, 1979 (hereinafter called the
Tenth Supplemental Indenture); its Eleventh Supplemental
Indenture, dated as of October 1, 1983 (hereinafter called the
Eleventh Supplemental Indenture); its Twelfth Supplemental
Indenture, dated as of January 1, 1984 (hereinafter called the
Twelfth Supplemental Indenture); its Thirteenth Supplemental
Indenture, dated as of December 1, 1991 (hereinafter called the
Thirteenth Supplemental Indenture); its Fourteenth Supplemental
Indenture, dated as of January 1, 1993 (hereinafter called the
Fourteenth Supplemental Indenture); its Fifteenth Supplemental
Indenture, dated as of March 1, 1993 (hereinafter called the
Fifteenth Supplemental Indenture) and its Sixteenth Supplemental
Indenture, dated as of May 1, 1993 (hereinafter called the
Sixteenth Supplemental Indenture); and

           WHEREAS, the First, Second, Third, Fourth, Fifth,
Sixth, Seventh, Eighth, Ninth, Tenth, Eleventh, Twelfth,
Thirteenth, Fourteenth, Fifteenth and Sixteenth Supplemental In-
dentures were or are to be recorded in the official records of
various counties in the states of Montana and Wyoming, which
counties include or will include all counties in which this
Seventeenth Supplemental Indenture is to be recorded; and

           WHEREAS, an instrument dated March 15, 1955 was
executed by the Company--New Jersey appointing Karl R. Henrich as
Co-Trustee in succession to said Arthur E. Burke, resigned, under
the Mortgage and by Karl R. Henrich accepting the appointment as
Co-Trustee under the Mortgage in succession to said Arthur E.
Burke, which instrument was recorded in various counties in the
states of Montana, Idaho and Wyoming; and


           WHEREAS, an instrument dated June 29, 1962 was executed
by the Company appointing H. H. Gould as Co-Trustee in succession
to said Karl R. Henrich, resigned, under the Mortgage and by H.
H. Gould accepting the appointment as Co-Trustee under the
Mortgage in succession to said Karl R. Henrich, which instrument
was recorded in various counties in the states of Montana, Idaho
and Wyoming; and

           WHEREAS, an instrument dated June 22, 1973 was executed
by the Company appointing R. Amundsen as Co-Trustee in succession
to said H. H. Gould, resigned, under the Mortgage and by R.
Amundsen accepting the appointment as Co-Trustee under the
Mortgage in succession to said H. H. Gould, which instrument was
recorded in various counties in the states of Montana, Idaho and
Wyoming; and

           WHEREAS, an instrument dated July 1, 1986 was executed
by the Company appointing P.J. Crowley as Co-Trustee in
succession to said R. Amundsen, resigned, under the Mortgage and
by P.J. Crowley accepting the appointment as Co-Trustee under the
Mortgage in succession to said R. Amundsen, which instrument was
recorded in various counties in the states of Montana, Idaho and
Wyoming; and

           WHEREAS, in addition to the property described in the
Mortgage, the Company has acquired certain other property, rights
and interests in property; and

           WHEREAS, the Company--New Jersey or the Company has
heretofore issued, in accordance with the provisions of the
Mortgage, the following series of First Mortgage Bonds:

                                                             Principal
                                        Principal Amount      Amount
               Series                        Issued         Outstanding   

2-7/8% Series due 1975 . . . . . . .     $  40,000,000         NONE
3-1/8% Series due 1984 . . . . . . .         6,000,000         NONE
4-1/2% Series due 1989 . . . . . . .        15,000,000         NONE
8-1/4% Series due 1974 . . . . . . .        30,000,000         NONE
7-1/2% Series due 2001 . . . . . . .        25,000,000      $25,000,000
8-5/8% Series due 2004 . . . . . . .        60,000,000         NONE
8-3/4% Series due 1981 . . . . . . .        30,000,000         NONE
9.60% Series due 2005. . . . . . . .        35,000,000         NONE
9.70% Series due 2005. . . . . . . .        65,000,000         NONE
9-7/8% Series due 2009 . . . . . . .        50,000,000         NONE
11-3/4% Series due 1993. . . . . . .        75,000,000         NONE
10/10-1/8% Series due 2004/2014. . .        80,000,000       80,000,000
8-1/8% Series due 2014 . . . . . . .        41,200,000         NONE
7.70% Series due 1999. . . . . . . .        55,000,000       55,000,000
8-1/4% Series due 2007 . . . . . . .        55,000,000       55,000,000
8.95% Series due 2022. . . . . . . .        50,000,000       50,000,000
Secured Medium-Term Notes. . . . . .        43,000,000       43,000,000
7% Series due 2005 . . . . . . . . .        50,000,000       50,000,000
6-1/8% Series due 2023 . . . . . . .        90,205,000       90,205,000


which bonds are also hereinafter sometimes called bonds of the
First through Nineteenth Series, respectively; and

           WHEREAS, Section 8 of the Mortgage provides that the
form of each series of bonds (other than the First Series) issued
thereunder and of the coupons to be attached to coupon bonds of
such series shall be established by Resolution of the Board of
Directors of the Company and that the form of such series, as
established by said Board of Directors, shall specify the
descriptive title of the bonds and various other terms thereof,
and may also contain such provisions not inconsistent with the
provisions of the Indenture as the Board of Directors may, in its
discretion, cause to be inserted therein expressing or referring
to the terms and conditions upon which such bonds are to be
issued and/or secured under the Indenture; and

           WHEREAS, Section 120 of the Mortgage provides, among
other things, that any power, privilege or right expressly or
impliedly reserved to or in any way conferred upon the Company by
any provision of the Indenture, whether such power, privilege or
right is in any way restricted or is unrestricted, may be in
whole or in part waived or surrendered or subjected to any
restriction if at the time unrestricted or to additional
restriction if already restricted, and the Company may enter into
any further covenants, limitations or restrictions for the bene-
fit of any one or more series of bonds issued thereunder, or the
Company may cure any ambiguity contained therein or in any
supplemental indenture or may (in lieu of establishment by
Resolution as provided in Section 8 of the Mortgage) establish
the terms and provisions of any series of bonds other than said
First Series, by an instrument in writing executed and
acknowledged by the Company in such manner as would be necessary
to entitle a conveyance of real estate to record in all of the
states in which any property at the time subject to the lien of
the Indenture shall be situated; and

           WHEREAS, the Company now desires to create a new series
of bonds and (pursuant to the provisions of Section 120 of the
Mortgage) to add to its covenants and agreements contained in the
Mortgage certain other covenants and agreements to be observed by
it and to alter and amend in certain respects the covenants and
provisions contained in the Indenture; and

           WHEREAS, the execution and delivery by the Company of
this Seventeenth Supplemental Indenture, and the terms of the
bonds of the Twentieth Series, hereinafter referred to, have been
duly authorized by the Board of Directors of the Company by
appropriate Resolutions of said Board of Directors;

           NOW THEREFORE, THIS INDENTURE WITNESSETH:  That the
Company, in consideration of the premises and of $1.00 to it duly
paid by the Trustees at or before the ensealing and delivery of
these presents, the receipt whereof is hereby acknowledged, and
in further evidence of assurance of the estate, title and rights
of the Trustees and in order further to secure the payment of
both the principal of and interest and premium, if any, on the
bonds from time to time issued under the Indenture, according to
their tenor and effect and the performance of all the provisions
of the Indenture (including any modification made as in the
Mortgage provided) and of said bonds, and to confirm the lien of
the Mortgage on certain after-acquired property, hereby grants,
bargains, sells, releases, conveys, assigns, transfers,
mortgages, pledges, sets over and confirms (subject, however, to
Excepted Encumbrances as defined in Section 6 of the Mortgage)
unto P.J. Crowley and (to the extent of its legal capacity to
hold the same for the purposes hereof) to Morgan Guaranty Trust
Company of New York, as Trustees under the Indenture, and to
their successor or successors in said trust, and to said Trustees
and their successors and assigns forever, all property, real,
personal and mixed, of the kind or nature specifically mentioned
in the Mortgage, as heretofore supplemented, or of any other kind
or nature (whether or not located in the State of Montana),
acquired by the Company after the date of the execution and
delivery of the Mortgage, as heretofore supplemented (except any
herein or in the Mortgage, as heretofore supplemented, expressly
excepted), now owned or, subject to the provisions of subsection
(I) of Section 87 of the Mortgage, hereafter acquired by the
Company (by purchase, consolidation, merger, donation,
construction, erection or in any other way) and wheresoever
situated, including (without in anywise limiting or impairing by
the enumeration of the same the scope and intent of the foregoing
or of any general description contained in the Indenture) all
lands, power sites, flowage rights, water rights, water
locations, water appropriations, ditches, flumes, reservoirs,
reservoir sites, canals, raceways, dams, dam sites, aqueducts,
and all other rights or means for appropriating, conveying, stor-
ing and supplying water; all rights of way and roads; all plants
for the generation of electricity by steam, water and/or other
power; all power houses, gas plants, street lighting systems,
standards and other equipment incidental thereto, telephone,
radio and television systems, air-conditioning systems and
equipment incidental thereto, water works, water systems, steam
heat and hot water plants, substations, lines, service and supply
systems, bridges, culverts, tracks, ice or refrigeration plants
and equipment, offices, buildings and other structures and the
equipment thereof; all machinery, engines, boilers, dynamos,
electric, gas and other machines, regulators, meters,
transformers, generators, motors, electrical, gas and mechanical
appliances, conduits, cables, water, steam heat, gas or other
pipes, gas mains and pipes, service pipes, fittings, valves and
connections, pole and transmission lines, wires, cables, tools,
implements, apparatus, furniture and chattels; all franchises,
consents or permits; all lines for the transmission and
distribution of electric current, gas, steam heat or water for
any purpose including towers, poles, wires, cables, pipes,
conduits, ducts and all apparatus for use in connection
therewith; all real estate, lands, easements, servitudes,
licenses, permits, franchises, privileges, rights of way and
other rights in or relating to real estate or the occupancy of
the same and (except as herein or in the Mortgage, as heretofore
supplemented, expressly excepted) all the right, title and
interest of the Company in and to all other property of any kind
or nature appertaining to and/or used and/or occupied and/or
enjoyed in connection with any property hereinbefore or in the
Mortgage, as heretofore supplemented, described.

           TOGETHER with all and singular the tenements,
hereditaments, prescriptions, servitudes and appurtenances
belonging or in anywise appertaining to the aforesaid property or
any part thereof, with the reversion and reversions, remainder
and remainders and (subject to the provisions of Section 57 of
the Mortgage) the tolls, rents, revenues, issues, earnings,
income, product and profits thereof, and all the estate, right,
title and interest and claim whatsoever, at law as well as in
equity, which the Company now has or may hereafter acquire in and
to the aforesaid property and franchises and every part and
parcel thereof.

           IT IS HEREBY AGREED by the Company that, subject to the
provisions of subsection (I) of Section 87 of the Mortgage, all
the property, rights, and franchises acquired by the Company (by
purchase, consolidation, merger, donation, construction, erection
or in any other way) after the date hereof, except any herein or
in the Mortgage, as heretofore supplemented, expressly excepted,
shall be and are as fully granted and conveyed hereby and as
fully embraced within the lien hereof and the lien of the Mort-
gage, as supplemented, as if such property, rights and franchises
were now owned by the Company and were specifically described
herein and conveyed hereby.

           PROVIDED that the following are not and are not
intended to be now or hereafter granted, bargained, sold,
released, conveyed, assigned, transferred, mortgaged, hy-
pothecated, affected, pledged, set over or confirmed hereunder
and are hereby expressly excepted from the lien and operation of
the Mortgage, as supplemented, namely:  (1) cash, shares of
stock, bonds, notes and other obligations and other securities
not specifically pledged, paid, deposited, delivered or held
under the Mortgage, as supplemented, or covenanted so to be; (2)
merchandise, equipment, apparatus, materials or supplies held for
the purpose of sale or other disposition in the usual course of
business; fuel, oil and similar materials and supplies consumable
in the operation of any of the properties of the Company; all
aircraft, tractors, rolling stock, trolley coaches, buses, motor
coaches, automobiles, motor trucks, and other vehicles and
materials and supplies held for the purpose of repairing or
replacing (in whole or part) any of the same; (3) bills, notes
and accounts receivable, judgments, demands and chooses in
action, and all contracts, leases and operating agreements not
specifically pledged under the Mortgage, as supplemented, or
covenanted so to be; the Company's contractual rights or other
interest in or with respect to tires not owned by the Company;
(4) the last day of the term of any lease or leasehold which may
be or become subject to the lien of the Mortgage, as
supplemented; (5) electric energy, gas, steam, water, ice, and
other materials or products generated, manufactured, produced,
purchased or acquired by the Company for sale, distribution or
use in the ordinary course of its business; all timber, minerals,
mineral rights and royalties and all Gas and Oil Production Prop-
erty, as defined in Section 4 of the Mortgage; (6) the Company's
franchise to be a corporation; and (7) any property heretofore
released pursuant to any provisions of the Indenture and not
heretofore disposed of by the Company; provided, however, that
the property and rights expressly excepted from the lien and
operation of the Mortgage, as supplemented, in the above
subdivisions (2) and (3) shall (to the extent permitted by law)
cease to be so excepted in the event and as of the date that
either or both of the Trustees or a receiver or trustee shall
enter upon and take possession of the Mortgaged and Pledged
Property in the manner provided in Article XIII of the Mortgage
by reason of the occurrence of a Default as defined in Section 65
thereof.

           TO HAVE AND TO HOLD all such properties, real, personal
and mixed, granted, bargained, sold, released, conveyed,
assigned, transferred, mortgaged, pledged, set over or confirmed
by the Company as aforesaid, or intended so to be, unto P.J.
CROWLEY and (to the extent of its legal capacity to hold the same
for the purposes hereof) unto MORGAN GUARANTY TRUST COMPANY OF
NEW YORK, as Trustees, and their successors and assigns forever.

           IN TRUST NEVERTHELESS, for the same purposes and upon
the same terms, trusts and conditions and subject to and with the
same provisos and covenants as are set forth in the Mortgage, as
supplemented, this Seventeenth Supplemental Indenture being
supplemental thereto.

           AND IT IS HEREBY COVENANTED by the Company that all the
terms, conditions, provisos, covenants and provisions contained
in the Mortgage, as supplemented, shall affect and apply to the
property hereinbefore described and conveyed and to the estate,
rights, obligations and duties of the Company and the Trustees
and the beneficiaries of the trust with respect to said property,
and to the Trustees and their successors as Trustees of said
property in the same manner and with the same effect as if the
said property had been owned at the time of the execution of the
Mortgage, and had been specifically and at length described in
and conveyed to the Trustees, by the Mortgage as a part of the
property therein stated to be conveyed.

           The Company further covenants and agrees to and with
the Trustees and their successors in said trust under the
Indenture, as follows:



                               ARTICLE I

                       Twentieth Series of Bonds

           Section 1.  There shall be a series of bonds designated
"5.90% Series due 2023" (herein sometimes referred to as the
"Twentieth Series"), each of which shall also bear the
descriptive title "First Mortgage Bond", and the form thereof,
which shall be established by Resolution of the Board of
Directors of the Company, shall contain suitable provisions with
respect to the matters hereinafter  in this Section
specified.  Bonds of the Twentieth Series shall mature on
December 1, 2023, and shall be issued as  fully registered bonds
in denominations of Five Thousand Dollars and in any multiple or
multiples of Five Thousand Dollars; they shall
bear interest at the rate of 5.90% per annum, payable
semiannually on June 1 and December 1 of each year; the principal
of and interest on each said bond to be payable at the office or
agency of the Company in the Borough of Manhattan, The City of
New York, in such coin or currency of the United States of
America as at the time of payment is legal tender for public and
private debts.  Bonds of the Twentieth Series shall be dated as
in Section 10 of the Mortgage provided.

           At the option of the registered owner, any bonds of the
Twentieth Series, upon surrender thereof for cancellation at the
office or agency of the Company in the Borough of Manhattan, The
City of New York, shall be exchangeable for a like aggregate
principal amount of bonds of the same series of other authorized
denominations.

           Bonds of the Twentieth Series shall not be transferable
except to any successor trustee under the Indenture of Trust,
dated as of December 1, 1993, of the City of Forsyth, Rosebud
County, Montana (hereinafter referred to as the "Forsyth
Indenture"), relating to the City of Forsyth, Rosebud County,
Montana, Pollution Control Revenue Refunding Bonds (The Montana
Power Company Colstrip Project) Series 1993B (hereinafter
referred to as the "Forsyth Bonds"), any such transfer to be made
(subject to the provisions of Section 12 of the Mortgage) at the
office or agency of the Company in the Borough of Manhattan, The
City of New York.

           Upon any exchange or transfer of bonds of the Twentieth
Series, the Company may make a charge therefor sufficient to
reimburse it for any tax or taxes or other governmental charge,
as provided in Section 12 of the Mortgage, but the Company hereby
waives any right to make a charge in addition thereto for any
exchange or transfer of bonds of the Twentieth Series.

           Upon the delivery of this Seventeenth Supplemental
Indenture, bonds of the Twentieth Series in the aggregate
principal amount of $80,000,000 are to be issued forthwith and
will be Outstanding in addition to $25,000,000 aggregate
principal amount of bonds of the Fifth series, $80,000,000
aggregate principal amount of bonds of the Twelfth Series,
$55,000,000 aggregate principal amount of bonds of the Fourteenth
Series, $55,000,000 aggregate principal amount of bonds of the
Fifteenth Series, $50,000,000 aggregate principal amount of bonds
of the Sixteenth Series, $43,000,000 aggregate principal amount
of bonds of the Seventeenth Series, $50,000,000 aggregate
principal amount of bonds of the Eighteenth Series and
$90,205,000 aggregate principal amount of bonds of the Nineteenth
Series Outstanding at the date of delivery of this Seventeenth
Supplemental Indenture.

           (I)  Upon the redemption, in whole or in part, of the
Forsyth Bonds, pursuant to Section 3.01(c) of the Forsyth
Indenture, bonds of the Twentieth Series shall be redeemed in
whole or in like part, as the case may be.  The Corporate Trustee
may conclusively presume that no redemption of bonds of the
Twentieth Series is required pursuant to this subdivision (I)
unless and until it shall have received a written notice from the
trustee under the Forsyth Indenture (hereinafter referred to as
the "Forsyth Trustee"), signed by its President, a Vice President
or a Trust Officer, stating that Forsyth Bonds are to be redeemed
pursuant to Section 3.01(c) of the Forsyth Indenture (said notice
is hereinafter referred to as the "Forsyth Redemption Demand"). 
The Forsyth Redemption Demand also shall state the date on which
the Forsyth Bonds are to be redeemed, the principal amount of
bonds of the Twentieth Series to be redeemed and that such amount
is equal to the principal amount of the Forsyth Bonds to be
redeemed and shall instruct the Corporate Trustee to call the
stated principal amount of bonds of the Twentieth Series for
redemption on the date on which the Forsyth Bonds are to be
redeemed.  The Forsyth Redemption Demand shall also contain a
waiver of notice of such redemption by the Forsyth Trustee, as
holder of all bonds of the Twentieth Series then Outstanding. 
The Corporate Trustee may conclusively presume the statements
contained in the Forsyth Redemption Demand to be correct. 
Redemption of bonds of the Twentieth Series shall be at the
principal amount of the bonds to be redeemed together with the
applicable accrued interest to the redemption date, and such
amount shall become due and payable on the redemption date.  The
Company hereby covenants that, if a Forsyth Redemption Demand
shall be delivered to the Corporate Trustee, the Company, subject
to subdivision (II) of this Article I, will deposit, on or before
the redemption date, with the Corporate Trustee, in accordance
with Article X of the Mortgage, an amount in cash sufficient to
redeem the bonds of the Twentieth Series so called for
redemption.

           (II) All bonds of the Twentieth Series shall be issued
and delivered to, and registered in the name of, the Forsyth
Trustee (or, subject to Section 6.11 of the Forsyth Indenture,
its nominee) in order to provide for the payment of the Company's
obligation to make certain payments under the Loan Agreement,
dated as of December 1, 1993, between the Company and the City of
Forsyth, Rosebud County, Montana, relating to the Forsyth Bonds. 
The obligation of the Company to make payments with respect to
the principal of and interest on bonds of the Twentieth Series
shall be fully or partially, as the case may be, satisfied and
discharged to the extent that, at the time that any such payment
shall be due, there shall be in the Bond Fund established
pursuant to the Forsyth Indenture sufficient available funds to
fully or partially pay the then due principal of and interest on
the Forsyth Bonds.  The Corporate Trustee may conclusively
presume that the obligation of the Company to make payments with
respect to the principal of and interest on bonds of the
Twentieth Series shall have been fully satisfied and discharged
unless and until the Corporate Trustee shall have received a
written notice from the Forsyth Trustee, signed by its President,
a Vice President or a Trust Officer, stating (i) that there are
not sufficient available funds in such Bond Fund to make timely
payment of the principal of or interest on the Forsyth Bonds, and
(ii) the amount of funds required to make such payment.  The
Corporate Trustee may conclusively presume the statements
contained in any such notice to be correct.




                              ARTICLE II
                       Miscellaneous Provisions

           Section 2.  Subject to the amendments provided for in
this Seventeenth Supplemental Indenture, the terms defined in the
Mortgage, as heretofore supplemented, shall, for all purposes of
this Seventeenth Supplemental Indenture, have the meanings spe-
cified in the Mortgage, as heretofore supplemented.

           Section 3.  The Trustees hereby accept the trusts
herein declared, provided, created or supplemented and agree to
perform the same upon the terms and conditions herein and in the
Mortgage, as heretofore supplemented, set forth and upon the
following terms and conditions:

           The Trustees shall not be responsible in any manner
whatsoever for or in respect of the validity or sufficiency of
this Seventeenth Supplemental Indenture or for or in respect of
the recitals contained herein, all of which recitals are made by
the Company solely.  In general, each and every term and
condition contained in Article XVII of the Mortgage shall apply
to and form part of this Seventeenth Supplemental Indenture with
the same force and effect as if the same were herein set forth in
full with such omissions, variations and insertions, if any, as
may be appropriate to make the same conform to the provisions of
this Seventeenth Supplemental Indenture.

           Section 4.  Whenever in this Seventeenth Supplemental
Indenture any of the parties hereto is named or referred to, this
shall, subject to the provisions of Articles XVI and XVII of the
Mortgage, be deemed to include the successors and assigns of such
party, and all the covenants and agreements in this Seventeenth
Supplemental Indenture contained by or on behalf of the Company,
or by or on behalf of the Trustees shall, subject as aforesaid,
bind and inure to the respective benefits of the respective suc-
cessors and assigns of such parties, whether so expressed or not.

           Section 5.  Nothing in this Seventeenth Supplemental
Indenture, expressed or implied, is intended, or shall be
construed, to confer upon, or to give to, any person, firm or
corporation, other than the parties hereto and the holders of the
bonds and coupons Outstanding under the Indenture, any right,
remedy or claim under or by reason of this Seventeenth
Supplemental Indenture or any covenant, condition, stipulation,
promise or agreement hereof, and all the covenants, conditions,
stipulations, promises and agreements in this Seventeenth
Supplemental Indenture contained by or on behalf of the Company
shall be for the sole and exclusive benefit of the parties
hereto, and of the holders of the bonds and coupons Outstanding
under the Indenture.

           Section 6.  This Seventeenth Supplemental Indenture
shall be executed in several counterparts, each of which shall be
an original and all of which shall constitute but one and the
same instrument.




           IN WITNESS WHEREOF, THE MONTANA POWER COMPANY has
caused its corporate name to be hereunto affixed, and this
instrument to be signed and sealed by its President or one of its
Vice Presidents, and its corporate seal to be attested by its
Secretary or one of its Assistant Secretaries for and in its
behalf, and MORGAN GUARANTY TRUST COMPANY OF NEW YORK, in token
of its acceptance of the trust hereby created, has caused  its
corporate name to be hereunto affixed, and this instrument to be
signed and sealed by one of its Vice Presidents or one of its
Trust Officers, and its corporate seal to be attested by one of
its Assistant Secretaries, and P.J. Crowley, for all like
purposes, has hereunto set his hand and affixed his seal, as of
the day and year first above written.

                                      THE MONTANA POWER COMPANY


                                      By:  /s/ J. P. Pederson
                                           Vice President
Attest:

/s/ Patricia L. du Toit                                 
Assistant Secretary


Executed, sealed and delivered by
THE MONTANA POWER COMPANY in the presence of:

/s/ Robert T. Hopewell

/s/ Jessica G. Eyde

                                 


                                 

                                      MORGAN GUARANTY TRUST COMPANY
                                        OF NEW YORK,
                                           as Corporate Trustee


                                      BY:   /s/ Catherine F. Donohue
                                            Trust Officer

Attest:

/s/ Diana M. Hils                                 
Assistant Secretary


                                            /s/ P. J. Crowley  
                                            P.J. CROWLEY, as Co-
                                              Trustee

Executed, sealed and delivered
by MORGAN GUARANTY TRUST COMPANY OF NEW
  YORK and P.J. CROWLEY in the presence of:

/s/ Allison M. Leuchick

/s/ Susan F. Donnelly
                                 

                                 



STATE OF MONTANA           )
                           )  ss.:
COUNTY OF SILVER BOW       )



           On this 10th day of December, in the year 1993, before
me, Susan Hawke, a Notary Public in and for the State of Montana,
personally came and appeared J. P. Pederson, to me known and
known to me to be a Vice President of THE MONTANA POWER COMPANY,
the corporation that executed the within instrument, and ac-
knowledged to me that such corporation executed the same, and
being by me duly sworn, did depose and say that he resides at
1829 Utah Avenue, Butte, Montana; that he is a Vice President of
THE MONTANA POWER COMPANY, the corporation described in and which
executed the within and above instrument;  that he knows the seal
of said corporation; that the seal affixed to said instrument is
such corporate seal; that it was so affixed by order of the Board
of Directors of said corporation, and that he signed his name
thereto by like order.

           IN WITNESS WHEREOF, I have hereunto subscribed my name
and affixed my official seal the day and year in this certificate
first above written.




                                 /s/ Susan Hawke 
                                 Susan Hawke
                                 Notary Public, State of Montana
                                 Residing at Butte, Montana
                                 My Commission Expires June 1, 1996




STATE OF NEW YORK     )
                      )  ss.:
COUNTY OF NEW YORK    )



           On this 14th day of December, 1993, before me, Thomas
J. Courtney, a Notary Public in and for the State of New York,
personally came and appeared Catherine F. Donohue, to me known
and known to me to be a Trust Officer of MORGAN GUARANTY TRUST
COMPANY OF NEW YORK, the corporation that executed the within
instrument, and acknowledged to me that such corporation executed
the same, and, being by me duly sworn, did depose and say that
she resides at Bronxville, New York; that she is a Trust Officer
of MORGAN GUARANTY TRUST COMPANY OF NEW YORK, the corporation de-
scribed in and which executed the within  and above instrument; 
that she knows the seal of said corporation;  that the seal
affixed to said instrument is such corporate seal; that it was so
affixed by authority of the Board of Directors of said
corporation, and that she signed her name thereto by like
authority.

           IN WITNESS WHEREOF, I have hereunto subscribed my name
and affixed my official seal the day and year in this certificate
first above written.



                                 /s/ Thomas J. Courtney  
                                 Thomas J. Courtney                    
                                 Notary Public, State of New York
                                    No. 24-4996233
                                 Qualified in Kings County
                                 Commission Expires May 11, 1994




STATE OF NEW YORK     )
                      )  ss.:
COUNTY OF NEW YORK    )



           On this 14th day of December, in the year 1993, before
me, Thomas J. Courtney, a Notary Public in and for the State of
New York, personally came and appeared P.J. CROWLEY, known to me
to be one of the persons described in and who executed the within
and foregoing instrument, and whose name is subscribed thereto,
and acknowledged to me that he executed the same.

           IN WITNESS WHEREOF, I have hereunto subscribed my name
and affixed my official seal the day and year in this certificate
first above written.




                                 /s/ Thomas J. Courtney 
                                 Thomas J. Courtney
                                 Notary Public, State of New York
                                    No. 24-4996233
                                 Qualified in Kings County
                                 Commission Expires May 11, 1994