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                         ARIZONA PUBLIC SERVICE COMPANY
               (formerly Central Arizona Light and Power Company)

                                       TO

                              THE BANK OF NEW YORK


                                         As trustee under Central  Arizona Light
                                           and Power Company's Mortgage and Deed
                                           of Trust, Dated as of July 1, 1946.


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

                       Fifty-fifth Supplemental Indenture

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


                            Dated as of April 1, 1997


                       This Mortgage covers real property,
                         personal property and chattels.



              This instrument and the above-mentioned Mortgage and
           Deed of Trust contain after-acquired property provisions.

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                       FIFTY-FIFTH SUPPLEMENTAL INDENTURE

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

         INDENTURE,  dated as of the 1st day of April,  1997,  made and  entered
into by and between ARIZONA PUBLIC SERVICE  COMPANY,  a corporation of the State
of Arizona,  the principal place of business and mailing address of which is 400
North Fifth Street,  Phoenix,  Arizona 85004  (hereinafter  sometimes called the
Company),  party of the first part, and THE BANK OF NEW YORK, a New York banking
corporation,  the  mailing  address of which is 101 Barclay  Street,  21st Floor
West, New York, New York 10286 (hereinafter sometimes called the Trustee), party
of the second part, as Trustee under the Mortgage and Deed of Trust, dated as of
July 1, 1946 (hereinafter called the Mortgage),  which Mortgage was executed and
delivered by the Company under its former name,  Central Arizona Light and Power
Company,  to secure  the  payment of bonds  issued or to be issued  under and in
accordance with the provisions of the Mortgage, reference to which said Mortgage
is hereby made, this Indenture (hereinafter called the Fifty-fifth  Supplemental
Indenture) being supplemental thereto;

         WHEREAS,  said Mortgage was recorded and filed in Counties in the State
of Arizona as follows:


                                                                                             Filed and Abstracted
                                                    Recorded as Real Mortgage                as Chattel Mortgage
                                                -----------------------------------          -------------------
                                                                                              Chattel
                                                  Date         Book or                        Mortgage
                       County                   Recorded       Docket          Page             Book         Page
                       ------                   --------       ------          ----         ------------     ----
                                                                                              
         Apache...........................       7-28-50          16              1               9           154
         Cochise..........................        2-3-53          80             28              19           292
         Coconino.........................       1-20-53          39              1              10           286
         Gila.............................       1-17-53          32             84              17            --
         Graham...........................       12-3-63          92             87              15           223
         Maricopa.........................        8-6-46         408            163              92           204
         Mohave...........................      11-13-57          28             68              12            13
         Navajo...........................      10-14-49          31            483              16           521
         Pima.............................       1-24-53         558            351              14            --
         Pinal............................      10-25-52          68             31              12           591
         Yavapai..........................        8-7-46          79              1              12           223
         Yuma.............................        8-1-47          58            173              21           265


and in Counties in the State of New Mexico as follows:

                                                                                              
         McKinley.........................       5-31-61          36            153               4           295
         San Juan.........................       1-31-61         472            140                (No. 72441)


the copy  recorded  in Yuma  County,  Arizona  also being  effective  for La Paz
County,  Arizona,  formed on December 31, 1982; and copies of said Mortgage were
filed with the office of the Bureau of Indian  Affairs at Window Rock,  Arizona,
and with the Navajo Tribe of Indians at Window Rock, Arizona, and in the offices
of the Secretary of State and the State Land  Department of the State of Arizona
(all the said  counties  and the said  offices  above  referred to being  herein
referred to as "jurisdictions"); and
                                       2

         WHEREAS, by the Mortgage,  the Company 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  Mortgage and to make subject to the
Lien of the Mortgage any property thereafter  acquired,  made or constructed and
intended to be subject to the Lien thereof; and

         WHEREAS,  the  Company  has  executed  and  delivered  to  the  Trustee
fifty-four  indentures  supplemental to the Mortgage  (hereinafter  respectively
called the First through the Fifty-fourth  Supplemental  Indentures) dated as of
December 1, 1947, April 1, 1949, February 1, 1950, December 1, 1950, February 1,
1953,  November 1, 1953, March 1, 1954, October 1, 1957, March 1, 1959, November
1, 1961, June 1, 1962, December 1, 1962,  September 1, 1963,  September 1, 1967,
April 1, 1970, March 15, 1972,  April 1, 1974,  February 15, 1975, June 1, 1975,
November 15, 1975, April 15, 1977,  January 15, 1978, March 1, 1979, October 15,
1979, May 15, 1980,  February 2, 1982, April 15, 1982, July 1, 1983, October 15,
1983, June 15, 1984,  January 15, 1985, May 1, 1985,  June 1, 1985,  November 1,
1985,  January 15, 1986,  March 1, 1986, May 1, 1986,  February 1, 1987, June 1,
1987,  November 15, 1987, April 1, 1989,  February 15, 1990, May 15, 1990, April
15, 1991,  December 15, 1991,  January 15, 1992,  March 1, 1992,  June 15, 1992,
February 1, 1993, August 1, 1993,  August 1, 1993,  September 15, 1993, March 1,
1994, and November 15, 1996, each of which has been or will be recorded or filed
in, or a  recording  or filing is or will be  effective  with  respect  to, each
jurisdiction referred to above; and

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

         WHEREAS,  the Company has  heretofore  issued,  in accordance  with the
provisions of the Mortgage, as heretofore  supplemented and amended,  bonds of a
series  entitled and  designated  First  Mortgage  Bonds, 2 3/4% Series due 1976
(hereinafter  called the bonds of the First Series),  in the aggregate principal
amount of Eight Million Five Hundred Thousand Dollars  ($8,500,000);  bonds of a
series  entitled and  designated  First  Mortgage  Bonds, 3 1/8% Series due 1977
(hereinafter  called the bonds of the Second Series), in the aggregate principal
amount of Two Million Five Hundred  Thousand  Dollars  ($2,500,000);  bonds of a
series  entitled  and  designated  First  Mortgage  Bonds,  3%  Series  due 1979
(hereinafter  called the bonds of the Third Series),  in the aggregate principal
amount of Four  Million  Dollars  ($4,000,000);  bonds of a series  entitled and
designated First Mortgage Bonds, 2 3/4% Series due 1980 (hereinafter  called the
bonds of the Fourth Series),  in the aggregate  principal amount of Five Million
Dollars  ($5,000,000);  bonds of a series entitled and designated First Mortgage
Bonds,  2 7/8%  Series  due 1980  (hereinafter  called  the  bonds of the  Fifth
Series), in the aggregate principal amount of Six Million Dollars  ($6,000,000);
bonds of a series  entitled and designated  First Mortgage  Bonds, 3 1/2% Series
due 1983  (hereinafter  called the bonds of the Sixth Series),  in the aggregate
principal   amount  of  Fourteen   Million   Five   Hundred   Thousand   Dollars
($14,500,000); bonds of a series entitled and designated First Mortgage Bonds, 3
1/2% Series due  November 1, 1983  (hereinafter  called the bonds of the Seventh
Series),  in the  aggregate  principal  amount  of Five  Million  Seven  Hundred
Twenty-three  Thousand  Dollars  ($5,723,000);  bonds of a series  entitled  and
designated First Mortgage Bonds, 3 1/4% Series due 1984 (hereinafter  called the
bonds of the  Eighth  Series),  in the  aggregate  principal  amount of  Fifteen
Million Dollars  ($15,000,000);  bonds of a series entitled and designated First
Mortgage  Bonds,  5 1/8%  Series due 1987  (hereinafter  called the bonds of the
Ninth Series),  in the aggregate  principal  amount of Fifteen  Million  Dollars
($15,000,000);  bonds of a series entitled and designated  First Mortgage Bonds,
4.70% Series due 1989 (hereinafter called the bonds of the Tenth Series), in the
aggregate principal amount of Twenty Million Dollars  ($20,000,000);  bonds of a
series  entitled and  designated  First  Mortgage  Bonds,  4.80% Series due 1991
(hereinafter  called  the  bonds  of the  Eleventh  Series),  in  the  aggregate
                                       3

principal amount of Thirty-five Million Dollars ($35,000,000); bonds of a series
entitled and designated First Mortgage Bonds, 4.45% Series due 1992 (hereinafter
called the bonds of the Twelfth  Series),  in the aggregate  principal amount of
Twenty-five  Million  Dollars  ($25,000,000);  bonds  of a series  entitled  and
designated First Mortgage Bonds,  4.40% Series due 1992 (hereinafter  called the
bonds  of  the  Thirteenth   Series),  in  the  aggregate  principal  amount  of
Twenty-five  Million  Dollars  ($25,000,000);  bonds  of a series  entitled  and
designated First Mortgage Bonds,  4.50% Series due 1993 (hereinafter  called the
bonds of the Fourteenth  Series),  in the aggregate  principal amount of Fifteen
Million Dollars  ($15,000,000);  bonds of a series entitled and designated First
Mortgage  Bonds,  6.25%  Series  due 1997  (hereinafter  called the bonds of the
Fifteenth  Series),  in the aggregate  principal  amount of Twenty-five  Million
Dollars ($25,000,000);  bonds of a series entitled and designated First Mortgage
Bonds,  8.50%  Series due 1975  (hereinafter  called the bonds of the  Sixteenth
Series),   in  the  aggregate   principal   amount  of  Thirty  Million  Dollars
($30,000,000);  bonds of a series entitled and designated  First Mortgage Bonds,
7.45% Series due 2002 (hereinafter called the bonds of the Seventeenth  Series),
in the aggregate principal amount of Sixty Million Dollars ($60,000,000);  bonds
of a series entitled and designated First Mortgage Bonds,  6.20% Series due 2004
(hereinafter  called  the  bonds of the  Eighteenth  Series),  in the  aggregate
principal  amount  of Fifty  Million  Dollars  ($50,000,000);  bonds of a series
entitled and designated First Mortgage Bonds, 9.50% Series due 1982 (hereinafter
called the bonds of the Nineteenth Series), in the aggregate principal amount of
One Hundred  Million  Dollars  ($100,000,000);  bonds of a series  entitled  and
designated First Mortgage Bonds,  9.80% Series due 1980 (hereinafter  called the
bonds  of  the  Twentieth  Series),   in  the  aggregate   principal  amount  of
Seventy-five  Million  Dollars  ($75,000,000);  bonds of a series  entitled  and
designated First Mortgage Bonds, 10.625% Series due 2000 (hereinafter called the
bonds  of  the  Twenty-first  Series),  in the  aggregate  principal  amount  of
Seventy-five  Million  Dollars  ($75,000,000);  bonds of a series  entitled  and
designated First Mortgage Bonds, 6.45% Series A due 2007 (hereinafter called the
bonds  of the  Twenty-second  Series),  in the  aggregate  principal  amount  of
Thirteen  Million  Dollars  ($13,000,000);   bonds  of  a  series  entitled  and
designated First Mortgage Bonds, 6.45% Series B due 2007 (hereinafter called the
bonds of the Twenty-third  Series),  in the aggregate principal amount of Thirty
Million Dollars  ($30,000,000);  bonds of a series entitled and designated First
Mortgage  Bonds,  6%  Series A due 2008  (hereinafter  called  the  bonds of the
Twenty-fourth  Series), in the aggregate principal amount of Thirty-four Million
Dollars ($34,000,000);  bonds of a series entitled and designated First Mortgage
Bonds,  9.95% Series due 2004 (hereinafter  called the bonds of the Twenty-fifth
Series),  in the aggregate  principal  amount of  Seventy-five  Million  Dollars
($75,000,000);  bonds of a series entitled and designated  First Mortgage Bonds,
12 1/8%  Series  due 2009  (hereinafter  called  the  bonds of the  Twenty-sixth
Series),  in the aggregate  principal  amount of  Seventy-five  Million  Dollars
($75,000,000);  bonds of a series entitled and designated  First Mortgage Bonds,
12 7/8%  Series due 2000  (hereinafter  called  the bonds of the  Twenty-seventh
Series),  in the aggregate  principal amount of One Hundred  Eighty-five Million
Dollars ($185,000,000); bonds of a series entitled and designated First Mortgage
Bonds,  10  3/8%  Series  due  1985   (hereinafter   called  the  bonds  of  the
Twenty-eighth  Series),  in the aggregate  principal amount of Sixty Million Two
Hundred Fifty Thousand  Dollars  ($60,250,000);  bonds of a series  entitled and
designated  First Mortgage Bonds,  16% Series due 1992  (hereinafter  called the
bonds of the  Twenty-ninth  Series),  in the aggregate  principal  amount of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated First Mortgage Bonds, 12 3/4% Series due 2013 (hereinafter called the
bonds of the Thirtieth Series), in the aggregate principal amount of One Hundred
Million Dollars ($100,000,000);  bonds of a series entitled and designated First
Mortgage  Bonds,  13 1/2% Series due 2013  (hereinafter  called the bonds of the
Thirty-first  Series),  in the aggregate principal amount of One Hundred Million
Dollars ($100,000,000); bonds of a series entitled and designated First Mortgage
Bonds, 15% Series due 1994  (hereinafter  called the bonds of the  Thirty-second
Series),  in the  aggregate  principal  amount of One  Hundred  Million  Dollars
($100,000,000);  bonds of a series entitled and designated First Mortgage Bonds,
12% Series due 1995 (hereinafter  called the bonds of the
                                       4

Thirty-third   Series),  in  the  aggregate  principal  amount  of  One  Hundred
Twenty-five  Million  Dollars  ($125,000,000);  bonds of a series  entitled  and
designated First Mortgage Bonds, 13 1/4% Series due 2007 (hereinafter called the
bonds of the Thirty-fourth  Series),  in the aggregate principal amount of Fifty
Million Dollars  ($50,000,000);  bonds of a series entitled and designated First
Mortgage  Bonds,  11 1/2% Series due 2015  (hereinafter  called the bonds of the
Thirty-fifth  Series),  in the aggregate  principal  amount of One Hundred Fifty
Million Dollars ($150,000,000);  bonds of a series entitled and designated First
Mortgage  Bonds,  11 1/2% Series due  November 1, 2015  (hereinafter  called the
bonds of the  Thirty-sixth  Series),  in the aggregate  principal  amount of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated  First Mortgage Bonds,  11% Series due 2016  (hereinafter  called the
bonds of the Thirty-seventh  Series),  in the aggregate  principal amount of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated First Mortgage Bonds, 9 1/4% Series due 1996 (hereinafter  called the
bonds of the  Thirty-eighth  Series),  in the aggregate  principal amount of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated  First Mortgage  Bonds,  9% Series due 1996  (hereinafter  called the
bonds of the  Thirty-ninth  Series),  in the aggregate  principal  amount of One
Hundred Twenty-five Million Dollars  ($125,000,000);  bonds of a series entitled
and designated First Mortgage Bonds, 9% Series due 2017 (hereinafter  called the
bonds of the Fortieth Series),  in the aggregate principal amount of One Hundred
Fifty Million Dollars ($150,000,000);  bonds of a series entitled and designated
First Mortgage  Bonds, 9 7/8% Series due 1997  (hereinafter  called the bonds of
the  Forty-first  Series),  in the  aggregate  principal  amount of One  Hundred
Twenty-five  Million  Dollars  ($125,000,000);  bonds of a series  entitled  and
designated First Mortgage Bonds, 10 3/4% Series due 2017 (hereinafter called the
bonds of the  Forty-second  Series),  in the aggregate  principal  amount of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated First Mortgage Bonds, 10 3/4% Series due 2019 (hereinafter called the
bonds of the  Forty-third  Series),  in the  aggregate  principal  amount of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated First Mortgage Bonds, 10 1/4% Series due 2000 (hereinafter called the
bonds of the  Forty-fourth  Series),  in the aggregate  principal  amount of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated First Mortgage Bonds, 10 1/4% Series due 2020 (hereinafter called the
bonds of the  Forty-fifth  Series),  in the  aggregate  principal  amount of One
Hundred Twenty-five Million Dollars  ($125,000,000);  bonds of a series entitled
and designated First Mortgage Bonds, 9 1/2% Series due 2021 (hereinafter  called
the bonds of the Forty-sixth  Series),  in the aggregate principal amount of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated  First Mortgage  Bonds,  9% Series due 2021  (hereinafter  called the
bonds of the  Forty-seventh  Series),  in the aggregate  principal amount of One
Hundred Fifty Million  Dollars  ($150,000,000);  bonds of a series  entitled and
designated  First  Mortgage  Bonds,  7 1/8%  Series due 1997,  in the  aggregate
principal amount of One Hundred Fifty Million Dollars ($150,000,000),  and bonds
of a series  entitled and  designated  First  Mortgage  Bonds, 8 3/4% Series due
2024,  in the aggregate  principal  amount of One Hundred  Seventy-five  Million
Dollars  ($175,000,000)  (hereinafter  collectively  called  the  bonds  of  the
Forty-eighth  Series);  bonds of a series entitled and designated First Mortgage
Bonds, 7 5/8% Series due 1998, in the aggregate  principal amount of One Hundred
Million  Dollars  ($100,000,000),  and bonds of a series entitled and designated
First Mortgage Bonds, 8 1/8% Series due 2002, in the aggregate  principal amount
of  One  Hundred   Twenty-five  Million  Dollars   ($125,000,000)   (hereinafter
collectively  called  the bonds of the  Forty-ninth  Series);  bonds of a series
entitled  and  designated   First  Mortgage   Bonds,  7  5/8%  Series  due  1999
(hereinafter  called  the  bonds  of the  Fiftieth  Series),  in  the  aggregate
principal  amount of One  Hundred  Million  Dollars  ($100,000,000);  bonds of a
series  entitled  and  designated  First  Mortgage  Bonds,  8%  Series  due 2025
(hereinafter  called  the bonds of the  Fifty-first  Series),  in the  aggregate
principal amount of One Hundred Fifty Million Dollars ($150,000,000); bonds of a
series  entitled and  designated  First  Mortgage  Bonds, 7 1/4% Series due 2023
(hereinafter  called the bonds of the  Fifty-second  Series),  in the  aggregate
principal  amount of One  Hundred  Million  Dollars  ($100,000,000);  bonds of a
series  entitled and  designated  First  Mortgage
                                       5

Bonds,  5 7/8%  Series due 2028  (hereinafter  called  bonds of the  Fifty-third
Series), in the aggregate principal amount of Twelve Million Eight Hundred Fifty
Thousand Dollars ($12,850,000);  bonds of a series entitled and designated First
Mortgage  Bonds,  5 7/8%  Series  due  2028  (hereinafter  called  bonds  of the
Fifty-fourth Series), in the aggregate principal amount of One Hundred Forty-one
Million One Hundred Fifty  Thousand  Dollars  ($141,150,000);  bonds of a series
entitled  and  designated   First  Mortgage   Bonds,  5  1/2%  Series  due  2028
(hereinafter called bonds of the Fifty-fifth Series), in the aggregate principal
amount of Twenty-five Million Dollars ($25,000,000);  bonds of a series entitled
and designated First Mortgage Bonds, 5 3/4% Series due 2000 (hereinafter  called
bonds of the  Fifty-sixth  Series)  in the  aggregate  principal  amount  of One
Hundred  Million  Dollars  ($100,000,000);   bonds  of  a  series  entitled  and
designated  First  Mortgage  Bonds, 6 5/8% Series due 2004  (hereinafter  called
bonds of the  Fifty-seventh  Series) in the  aggregate  principal  amount of One
Hundred  Million  Dollars  ($100,000,000);  and bonds of a series  entitled  and
designated First Mortgage Bonds,  Senior Note Series A (hereinafter called bonds
of the  Fifty-eighth  Series) in the aggregate  principal  amount of One Hundred
Million Dollars ($100,000,000); and

         WHEREAS,  said The  Bank of New  York,  by an  instrument  in  writing,
effective on the opening of business on September 29, 1995, succeeded to Bank of
America  National  Trust and Savings  Association as Trustee under the Mortgage;
and,  pursuant  to  Section  104 of the  Mortgage,  The  Bank of New York is the
successor Trustee under the Mortgage; and

         WHEREAS,  Section  8 of the  Mortgage  provides  that  the form of each
series of bonds (other than bonds of the First Series) issued  thereunder  shall
be  established  by Resolution of the Board of Directors of the Company and that
the form of each  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
Mortgage 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 Mortgage; 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 Mortgage, 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
benefit 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
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 Mortgage shall be situated; and

         WHEREAS,  the Company now desires to create a new series of bonds to be
issued under and pursuant to the Mortgage in accordance  with the  provisions of
Article VI thereof,  and to add to its covenants and agreements contained in the
Mortgage,  as heretofore  supplemented and amended,  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 Mortgage,  as heretofore  supplemented
and amended; and

         WHEREAS,  the  Company  has  agreed  to  issue  Fifty  Million  Dollars
($50,000,000)  in aggregate  principal amount of its 6.72% Senior Notes Due 1999
(the "Senior Notes Due 1999")  pursuant to the provisions of the Indenture dated
as of November 15, 1996 (the "Senior Note  Indenture"),  between the 
                                       6

Company  and The Bank of New York,  as trustee  (said  trustee or any  successor
trustee under the Senior Note  Indenture  being  hereinafter  referred to as the
"Senior Note Trustee"),  as supplemented  by the First  Supplemental  Indenture,
dated as of November 15, 1996, and the Second Supplemental Indenture dated as of
April 1, 1997, between the Company and the Senior Note Trustee; and

         WHEREAS, in order to secure the Company's  obligation to pay principal,
premium,  if any, and interest on the Senior Notes Due 1999 prior to the Release
Date (as hereinafter  defined),  the Company desires to provide for the issuance
under  the  Mortgage  to the  Senior  Note  Trustee  of a new  series  of  bonds
designated "First Mortgage Bonds, Senior Note Series B," having the same rate of
interest, interest payment dates, maturity date and redemption provisions and in
the same aggregate principal amount as the Senior Notes Due 1999; and

         WHEREAS,  the execution and delivery by the Company of this Fifty-fifth
Supplemental  Indenture,  and the terms of the bonds of the  Fifty-ninth  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 Arizona Public Service
Company,  in  consideration of the premises and of One Dollar to it duly paid by
the  Trustee 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 Trustee 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  heretofore,  herewith or hereafter issued under the Mortgage,
according to their tenor and effect,  and the  performance of all the provisions
of  the  Mortgage  (including  any  instruments  supplemental  thereto  and  any
modifications  made  as in the  Mortgage  provided)  and of said  bonds,  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 The Bank of New York,  as Trustee
under the Mortgage,  and to its  successor or  successors in said trust,  and to
said Trustee and its successors and assigns  forever,  all the properties of the
Company  described  in the  Mortgage,  as  heretofore  supplemented  and amended
(except any properties  which have been released from the Lien of the Mortgage),
and all the properties specifically described in Article V hereof.

         Also all other  property,  real,  personal  and  mixed,  of the kind or
nature specifically mentioned in Article V hereof or of any other kind or nature
(except any herein or in the Mortgage,  as heretofore  supplemented and amended,
expressly excepted and except any which may not lawfully be mortgaged or pledged
hereunder), 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 this  Fifty-fifth  Supplemental  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,  storing 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 equipment  thereof;  all machinery,  engines,  boilers,
dynamos,  electric, gas and other machines,  regulators,  meters,  transformers,
generators, motors, electrical, gas and 
                                       7

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 public or private  property,  real or personal,  or the occupancy of
such  property  and  (except  as  herein  or  in  the  Mortgage,  as  heretofore
supplemented and amended,  expressly excepted) all the right, title and interest
the Company may now have or hereafter  acquire in and to any and all 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 and amended, described.

         TOGETHER   WITH  all  and   singular  the   tenements,   hereditaments,
prescriptions, servitudes and appurtenances belonging or in anywise appertaining
to the  aforementioned  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,  interest and
claim whatsoever,  at law as well as in equity, which the Company now has or may
hereafter acquire in and to the aforementioned 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 and to the extent permitted by law,
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 and amended,  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 Mortgage 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,  pledged,  set over or confirmed  hereunder and are hereby  expressly
excepted from the lien and operation of this Fifty-fifth  Supplemental Indenture
and from the Lien and  operation  of the  Mortgage,  viz.:  (1) cash,  shares of
stock,  bonds,  notes and other  obligations and other  securities not hereafter
specifically pledged,  paid, deposited,  delivered or held under the Mortgage 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;  construction  equipment
acquired for  temporary  use; 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; all timber, minerals, mineral rights and royalties and
all  Natural  Gas and Oil  Production  Property,  as defined in Section 4 of the
Mortgage;  (3) bills,  notes and  accounts  receivable,  judgments,  demands and
choses in  action,  and all  contracts,  leases  and  operating  agreements  not
specifically pledged under the Mortgage or covenanted so to be; (4) the last day
of the term of any lease or leasehold which may be or become subject to the Lien
of the Mortgage;  (5) electric  energy,  gas, steam,  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;  and (6)
the  Company's  franchise  to be a  corporation;  provided,  however,  that  the
property  and  rights  expressly  excepted  from the Lien and  operation  of the
Mortgage in the above subdivisions (2) and (3) shall (to the extent permitted by
law)
                                       8

cease to be so  excepted  in the event and as of the date that the  Trustee 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 The Bank of New York,  the  Trustee,  and its  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 and amended.

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

         The Company  further  covenants  and agrees to and with the Trustee and
its successors in said trust under the Mortgage, as follows:


                                   ARTICLE I.
                          FIFTY-NINTH SERIES OF BONDS.

         SECTION 1. There shall be a series of bonds designated  "First Mortgage
Bonds,  Senior  Note  Series  B"  (hereinafter  sometimes  referred  to  as  the
"Fifty-ninth  Series"  or the  "Senior  Note  Series B  Bonds"),  limited to the
aggregate  principal  amount of  $50,000,000,  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 specified in
this Supplemental  Indenture.  Bonds of the Fifty-ninth Series shall be dated as
provided in Section 10 of the Mortgage;  shall mature, subject to the provisions
for prior redemption hereinafter set forth, on April 1, 1999; shall be issued as
fully  registered bonds in denominations of One Thousand Dollars or any integral
multiple  thereof,  and  shall  be  registered  in the name of the  Senior  Note
Trustee;  and shall bear  interest from  April 10, 1997 or from the most  recent
Interest  Payment Date (as defined below) to which interest has been paid at the
rate of 6.72% per  annum  (calculated  on the basis of a 360-day  year of twelve
30-day months), payable on April 1 and October 1 of each year (each an "Interest
Payment Date"), commencing  October 1, 1997, to the holders thereof of record on
the March 15 or September 15, as the case may be, next  preceding  such Interest
Payment Date (subject to the provisions of Section 12 of the Mortgage concerning
legal  holidays and bank  closings),  and the  principal of and interest on, and
premium or other amounts,  if any, payable upon redemption of, each said bond to
be payable at the office or agency of the Company in the  Borough of  Manhattan,
The City of New York, 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; provided,  however, that payment of interest may be made at
                                       9

the option of the Company by check mailed to the address of the person  entitled
thereto as such address shall appear on the registration books of the Company.

         The  Company's   obligation  to  make  payments  with  respect  to  the
principal,  premium  and/or  interest on the Senior Note Series B Bonds 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, the  corresponding  amount
of principal of,  premium,  if any, and/or interest then due on the Senior Notes
Due 1999 shall have been fully or partially  paid,  as the case may be, or there
shall have been deposited with the Senior Note Trustee  pursuant to Section 501,
Section  1103,  Section  1205 or Article  Fourteen of the Senior Note  Indenture
trust funds  sufficient  under the  provisions  of said  Sections and Article to
fully or  partially  pay,  as the  case  may be,  the  corresponding  amount  of
principal,  premium,  if any,  and/or  interest then due on the Senior Notes Due
1999.

         SECTION 2. Upon  payment of the  principal  of,  premium,  if any,  and
interest  due on the  Senior  Notes Due 1999,  whether at  maturity  or prior to
maturity by redemption or otherwise,  or upon provision for the payment  thereof
having been made in  accordance  with  Section 501 or Section 1402 of the Senior
Note  Indenture,  Senior Note Series B Bonds in a principal  amount equal to the
principal  amount of Senior  Notes Due 1999 so paid or for which such  provision
for payment has been made shall be deemed fully paid,  satisfied and  discharged
and the  obligations  of the Company  thereunder  shall be  terminated  and such
Senior Note Series B Bonds shall be surrendered to and cancelled by the Trustee.
From and after such date as all bonds  issued  under the  Mortgage  (other  than
Senior  Note First  Mortgage  Bonds,  as such term is defined in the Senior Note
Indenture)  have been retired  through  payment,  redemption,  or otherwise  at,
before or after maturity thereof (the "Release Date"),  the Senior Note Series B
Bonds shall be deemed fully paid, satisfied and discharged and the obligation of
the Company thereunder shall be terminated. On the Release Date, the Senior Note
Series B Bonds shall be surrendered to and cancelled by the Trustee.

         SECTION  3. At the  option of the  registered  owner,  any bonds of the
Fifty-ninth Series, upon surrender thereof,  for cancellation,  at the office or
agency of the Company in the  Borough of  Manhattan,  The City of New York,  New
York, together with a written instrument of transfer, if required by the Company
or by  the  Trustee,  duly  executed  by the  registered  owner  or by his  duly
authorized  attorney,  shall  (subject  to the  provisions  of Section 12 of the
Mortgage) be  exchangeable  for a like  aggregate  principal  amount of bonds in
registered  form of the same series of other  authorized  denominations  without
payment of any sum other than taxes or other governmental charges.

         Bonds of the Fifty-ninth  Series shall be transferable  (subject to the
provisions  of  Section  12 of the  Mortgage)  at said  office  or agency of the
Company  without  payment  of any sum  other  than  taxes or other  governmental
charges.

                                   ARTICLE II.
                    REDEMPTION OF SENIOR NOTE SERIES B BONDS

         The Senior Note Series B Bonds shall be redeemed,  in whole or in part,
from  time to time,  on the date on which a  corresponding  principal  amount of
Senior Notes Due 1999 are redeemed as provided in the Senior Note Indenture upon
the Senior Note Trustee's  notification of the Trustee of such redemption,  at a
redemption  price equal to the  redemption  price of such Senior  Notes Due 1999
being so  redeemed.  Any such  notice  shall be received by the Trustee no later
than 5 days prior to any  redemption  date fixed for the  Senior  Note  Series B
Bonds to be redeemed and shall specify the principal  amount of such Senior Note
Series B Bonds to be redeemed,  the  redemption  date, and the amount of accrued
interest and premium,  if any, to be paid thereon.  The Company shall deposit in
trust with the Trustee on the redemption  date an 
                                       10

amount  of  money  sufficient  to pay the  principal  amount  including  accrued
interest,  if any, and premium,  if any, on the Senior Note Series B Bonds to be
redeemed.  Upon presentation to the Trustee of any Senior Note Series B Bonds by
the  Senior  Note  Trustee  for  payment,  such  Senior  Note  Series B Bonds so
presented shall be redeemed and paid in full.

         In the event the principal of all Senior Notes Due 1999 is declared due
and payable or becomes  automatically due and payable pursuant to Section 602 of
the Senior Note Indenture,  upon the filing with the Trustee of a written demand
for the  acceleration  of the payment of  principal  of all Senior Note Series B
Bonds,  the payment of  principal on all Senior Note Series B Bonds shall become
immediately  due and payable and the  Trustee  shall  provide to the Senior Note
Trustee an irrevocable,  valid and  unconditional  notice of acceleration of all
Senior Note Series B Bonds.

         Redemption of the Senior Note Series B Bonds shall be effected, without
further  notice by the Company to the Trustee,  by the payment by the Company of
the  applicable  redemption  price  specified  in this  Article  II at the place
specified for payment of principal of and interest on such bonds.

         The Senior  Note  Series B Bonds will not be subject to  prepayment  or
redemption  prior to maturity  except as provided  herein,  notwithstanding  the
provisions  of Section 39 or Section 64 of the  Mortgage,  or with  "Proceeds of
Released Property," as defined in the Mortgage.

         The Senior Note Series B Bonds will not be subject to any sinking fund.

         The Company  covenants and agrees that,  prior to Release Date, it will
not take any action  (except as required by this  Article II hereof)  that would
cause the outstanding  principal  amount of the Senior Note Series B Bonds to be
less than the then outstanding principal amount of the Senior Notes Due 1999.

                                  ARTICLE III.
             REPLACEMENT FUND PROVISIONS -- OTHER RELATED PROVISIONS
             OF THE MORTGAGE -- DIVIDEND COVENANT -- RECORD DATES --
                              AUTHENTICATING AGENT.

         SECTION 4. The Company  covenants  that the provisions of Section 39 of
the  Mortgage,  which were to remain in effect so long as any bonds of the First
Series  remained  Outstanding,  shall remain in full force and effect so long as
any bonds of the Thirty-fourth,  Forty-third, Forty-fourth,  Forty-fifth, Forth-
sixth,  Forty-seventh,   Forty-ninth,   Fiftieth,   Fifty-first,   Fifty-second,
Fifty-third,    Fifty-fourth,     Fifty-fifth,    Fifty-sixth,    Fifty-seventh,
Fifty-eighth, or Fifty-ninth Series are Outstanding.

         Clause  (d)  of  subsection  (II)  of  Section  4 of the  Mortgage,  as
heretofore amended,  clause (6) and clause (e) of Section 5 of the Mortgage,  as
heretofore amended,  and Section 29 of the Mortgage,  as heretofore amended, are
hereby further amended by inserting  therein the words "and Fifty-ninth  Series"
after the words  "bonds of the First  Series and Second  Series and Third Series
and Fourth  Series  and Fifth  Series and Sixth  Series and  Seventh  Series and
Eighth Series and Ninth Series and Tenth Series and Eleventh  Series and Twelfth
Series and  Thirteenth  Series and  Fourteenth  Series and Fifteenth  Series and
Sixteenth  Series and  Seventeenth  Series and Eighteenth  Series and Nineteenth
Series and Twentieth Series and Twenty-first Series and Twenty-second Series and
Twenty-third  Series  and  Twenty-fourth  Series  and  Twenty-fifth  Series  and
Twenty-sixth  Series  and  Twenty-seventh  Series and  Twenty-eighth  Series and
Twenty-ninth   Series  and  Thirtieth   Series  and   Thirty-first   Series  and
Thirty-second  Series  and  Thirty-third  Series  and  Thirty-fourth  Series and
Thirty-fifth  Series  and  Thirty-sixth  Series  and  Thirty-seventh  Series and
Thirty-eighth Series and Thirty-ninth Series and Fortieth Series and 
                                       11

Forty-first   Series  and  Forty-second   Series  and  Forty-third   Series  and
Forty-fourth   Series  and  Forty-fifth   Series  and  Forty-sixth   Series  and
Forty-seventh Series and Forty-eighth Series and Forty-ninth Series and Fiftieth
Series and Fifty-first Series and Fifty-second Series and Fifty-third Series and
Fifty-fourth   Series  and  Fifty-fifth   Series  and  Fifty-sixth   Series  and
Fifty-seventh  Series  and  Fifty-eighth  Series"  each  time such  words  occur
therein.

         Clause  (e)  of  subsection  (II)  of  Section  4 of the  Mortgage,  as
heretofore amended, is hereby further amended by the insertion therein after the
words "and Fifty-eighth" the words "and Fifty-ninth."

         The  last  paragraph  of  Section  12 of the  Mortgage,  as  heretofore
amended,  the last  paragraph  of  Section  17 of the  Mortgage,  as  heretofore
amended,  and the last  paragraph of Section 110 of the Mortgage,  as heretofore
amended,  are hereby amended by inserting  therein the words "or the Fifty-ninth
Series"  after the words  "Fifty-eighth  Series"  each  time  such  words  occur
therein..


                                   ARTICLE IV.
                            MISCELLANEOUS PROVISIONS.

         SECTION  5. The terms  defined in the  Mortgage,  as  supplemented  and
amended,  shall,  for all purposes of this Fifty-fifth  Supplemental  Indenture,
have the meanings specified therein,  except that the term "Mortgage" shall mean
only the original Mortgage and Deed of Trust, dated as of July 1, 1946; the term
"Mortgage,  as heretofore  supplemented and amended" shall mean the Mortgage, as
supplemented  and  amended  by  the  First  through  Fifty-fourth   Supplemental
Indentures hereinabove referred to; and the term "Mortgage,  as supplemented and
amended,"  shall mean the  Mortgage,  as  supplemented  and amended by the First
through  Fifty-fourth  Supplemental  Indentures  hereinabove  referred to and as
supplemented  and amended by this  Fifty-fifth  Supplemental  Indenture  and any
future supplemental indentures.

         SECTION 6. The  Trustee  hereby  accepts  the trusts  herein  declared,
provided,  created,  supplemented or amended and agrees to perform the same upon
the terms and conditions herein and in the Mortgage, as heretofore  supplemented
and amended, set forth and upon the following terms and conditions:

         The Trustee shall not be responsible in any manner whatsoever for or in
respect  of  the  validity  or  sufficiency  of  this  Fifty-fifth  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 Fifty-fifth  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 Fifty-fifth Supplemental Indenture.

         SECTION 7. Whenever in this Fifty-fifth  Supplemental  Indenture either
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 Fifty-fifth Supplemental Indenture contained by or on behalf of the Company
or by or on behalf of the Trustee shall, subject as aforesaid, bind and inure to
the  respective  benefits  of the  respective  successors  and  assigns  of such
parties, whether so expressed or not.
                                       12

         SECTION  8.  Nothing  in  this  Fifty-fifth   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 Outstanding under the Mortgage,  any right, remedy or claim
under or by reason of this Fifty-fifth  Supplemental  Indenture or any covenant,
condition,  stipulation,  promise or agreement  hereof,  and all the  covenants,
conditions,   stipulations,   promises  and   agreements  in  this   Fifty-fifth
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
Outstanding under the Mortgage.

         SECTION 9. This  Fifty-fifth  Supplemental  Indenture  may be  executed
simultaneously in several  counterparts,  each of which shall be an original and
all of which shall constitute but one and the same instrument.


                                   ARTICLE V.
                        SPECIFIC DESCRIPTION OF PROPERTY.

         SECTION 10.  CERTAIN REAL PROPERTY LOCATED IN:

                                 MARICOPA COUNTY

                               Javelina Substation

That portion of the Southeast  quarter of the Southeast quarter of the Southeast
quarter of Section 1, Township 3 North,  Range 2 West of the Gila and Salt River
Base and Meridian,  Maricopa County,  Arizona,  more  particularly  described as
follows:

         COMMENCING  at the Southeast  corner of said  Section;  
     Thence North  00  degrees 59 minutes 19 seconds West along the East line of
         said Section 1, a distance of 420 feet to the POINT OF BEGINNING of the
         property herein described;
     Thence South 89 degrees 00 minutes 41 seconds West, 305 feet;  
     Thence North 00 degrees 59 minutes 19 seconds West, 240 feet; 
     Thence North 89 degrees 00 minutes 41  seconds East, 305 feet to a point on
         the East line of said  Section 1, said point  bears North 00 degrees 59
         minutes 19 seconds  West,  660 feet from the  Southeast  corner of said
         Section 1;
     Thence South 00 degrees 59 minutes 19 seconds  East along said East Section
         line, a distance of 240 feet to the POINT OF BEGINNING.
         EXCEPT the East 33 feet.

                                  MOHAVE COUNTY

                               Kingman Power Plant

Parcel 14-B as shown on the Record of Survey recorded September 19, 1996 in Book
14 of Records of  Survey,  Page 64, and being a portion of Parcel  14-B shown on
Record of Survey  recorded  October 16,  1995,  in Book 13 of Records of Survey,
Page 23,  being  located in the North half  (N1/2) of Section  14,  Township  19
North,  Range  18 West of the  Gila and Salt  River  Base and  Meridian,  Mohave
County, Arizona.
                                       13

TOGETHER WITH an easement for ingress, egress, and public utilities installation
located  within the  easement  shown on Record of Survey  recorded in Book 14 of
Records of Survey, Page 64, described as follows:

Beginning at the Northeast corner of said Section 14, being a found 2 inch brass
disk in concrete, down 1.5 feet on dirt road, LS 6452; thence South 0 degrees 13
minutes 47 seconds  West along the East line of said  Section  14, a distance of
42.00 feet to a point on the current Southerly right-of-way line of Yucca Drive,
being a found 5/8 inch rebar with an aluminum  cap stamped LS 25074,  Holmquist,
herein described as (mon.), said point being the TRUE POINT OF BEGINNING; thence
South 0 degrees 13 minutes 47 seconds  West along said East line,  a distance of
8.00 feet to mon.;  thence North 89 degrees 40 minutes 57 seconds West  parallel
to and 50.00 feet  Southerly of the North line of said Section 14, a distance of
264.92 feet to a mon. and a point of a curvature;  thence  Southwesterly along a
curve LEFT, an arc distance of 78.62 feet,  having a radius of 50.00 feet, and a
delta of 90 degrees 05 minutes 29 seconds to a mon.;  thence  South 0 degrees 13
minutes 47 seconds West, a distance of 599.85 feet to a mon., and a point on the
Northerly  line of Parcel 14-B1 (ROS 14/64);  thence North 89 degrees 46 minutes
13 seconds West along said Northerly  line, a distance of 100.00 feet to a mon.;
thence North 0 degrees 13 minutes 47 seconds  East, a distance of 600.15 feet to
a mon., and a point of curvature;  thence  Northwesterly  along a curve LEFT, an
arc  distance  of 78.46 feet,  having a radius of 50.00 feet,  and a delta of 89
degrees 54 minutes  31 seconds to a mon.;  thence  North 0 degrees 19 minutes 03
seconds  East,  a  distance  of 8.00  feet to a point on the  current  Southerly
right-of-way line of Yucca Drive;  thence South 89 degrees 40 minutes 57 seconds
East along said  right-of-way  line,  a  distance  of 464.91  feet more or less,
returning to the TRUE POINT OF BEGINNING.

                                 YAVAPAI COUNTY

                            Prescott Service Center A

That portion of Sheldon Street of the Original  Townsite of Prescott as recorded
in Book 4 of Maps,  and  Plats,  Page 22 on file at the  Office  of the  Yavapai
County  Recorder,  Yavapai  County,  Arizona,  more  particularly  described  as
follows:

Commencing at the  intersection  of the Westerly  right-of-way of Granite Street
and the Southerly  right-of-way of Sheldon Street,  said intersection point also
being the Northeast corner of Lot 1, Block "A" of said original Townsite; 
Thence West (assumed  bearing) along the Southerly  right-of-way of said Sheldon
Street, 209.12 feet to the TRUE POINT OF BEGINNING of this description;
Thence continuing West along the said Southerly  right-of-way of Sheldon Street,
124.12 feet to the  intersection  of the said Southerly  right-of-way of Sheldon
Street and the Easterly right-of-way of McCormick Street in said block "A";
Thence North,  66.25 feet to the  intersection of the Northerly  right-of-way of
said Sheldon Street and the Northerly  prolongation of the Easterly right-of-way
of McCormick Street;
Thence East along the  Northerly  right-of-way  of said Sheldon  Street,  124.12
feet;
Thence South, 66.25 feet to the TRUE POINT OF BEGINNING.
                                       14

                            Prescott Service Center B

That part of Lot 7, Section 33, Township 14 North,  Range 2 West of the Gila and
Salt River Base and Meridian, Yavapai County, Arizona, described as follows:

COMMENCING  at that  certain  point from whence the one  quarter  corner of said
Section 33 and Section 34 bears  North 60' 11" East a distance of 2571.65  feet;
thence North 0(degree) 46' 43" East, a distance of 130 feet to a point;
thence South  89(degree) 13' 17" East, a distance of 180 feet to a point;  
thence North 0(degree) 46' 43" East, a distance of 75 feet to a point;
thence South 89(degree) 13'17" East, a distance of 160 feet to a point;
thence North  0(degree) 46' 43" East a distance of 150 feet to the TRUE POINT OF
BEGINNING;
thence North 56(degree) 00' East 48.2 feet to a corner of the property described
in  instrument  recorded  in Book 158 of Deeds,  page 389,  records  of  Yavapai
County, Arizona;
thence  along the Westerly  boundary  line of property  described in  instrument
recorded in Book 158 of Deeds,  page 389,  records of Yavapai  County,  Arizona,
over the following courses:

         East 13.0 feet to a point;
         North 5(degree) 00' East 32.0 feet to a point;
         North 85(degree) 00' West 16.0 feet to a point;
         North 4(degree) 01' East 25.7 feet to a point;
         North 59(degree) 14' East to the point of intersection

with the Southerly  boundary line or the Easterly  extension thereof of Bashford
Addition  First  Subdivision,  accord  to Book 2 of Maps,  page 94,  records  of
Yavapai County,  Arizona;  thence Westerly along the said Southerly line and the
Easterly  extension  thereof of said Bashford  Addition First Subdivision to the
point of intersection with the Easterly line of property described in instrument
recorded in Book 19 of Deeds, page 575, records of Yavapai County, Arizona;

thence  Southerly  along  the  said  Easterly  line  of  property  described  in
instrument  recorded in Book 19 of Deeds,  page 575,  records of Yavapai County,
Arizona,  to the  point of  intersection  with the  Northerly  boundary  line of
property described in Parcel 3 of instrument recorded in Book 193 of Deeds, page
46, records of Yavapai  County,  Arizona; 
thence  North  89(degree)  13' 17" West along  said  Northerly  boundary  line a
distance of 325 feet;
thence North 0(degree) 46' 43" East, a distance of 20 feet to a point;
thence south  89(degree)  13' 17" East, a distance of 160 feet to the TRUE POINT
OF BEGINNING.

         SECTION 11. THE  ELECTRIC  SUBSTATIONS  OF THE COMPANY,  including  all
buildings,  structures, towers, poles, all equipment, appliances and devices for
transforming, converting and distributing electric energy, and all land owned by
the  Company  upon  which  the  same  are  situated,  and  all of the  Company's
easements,  rights of way, rights, machinery,  equipment,  appliances,  devices,
licenses  and  supplies  forming  a part of said  substations,  or any of  them,
including additions and improvements to any of the foregoing, or used or enjoyed
or capable of being used or enjoyed in conjunction with any thereof.

         SECTION 12.  Additions,  extensions  and  improvements  to THE ELECTRIC
TRANSMISSION SYSTEMS of the Company including,  among other things, 4.3 miles of
69kV from  Willow Lake to Bald  Mountain;  3.0 miles of 69kV from Casa Grande to
East Gate Tap;  242.7 miles of 500kV (joint  ownership)  from West Wing to Mead;
and 13.3 miles of 500kV (joint ownership) from Mead to Market Place.
                                       15

         SECTION 13.  Additions,  extensions  and  improvements  to THE ELECTRIC
DISTRIBUTION  SYSTEMS of the Company,  including the  construction of additional
facilities  throughout  the  Company's  service  area,  as well as  extension of
residential  and  downtown  underground   distribution   facilities,   including
associated  distribution equipment such as voltage regulators,  capacitor banks,
sectionalizing  equipment,  transformers,  street lighting  systems,  meters and
services, including reconstruction and improvements to provide efficient Company
operation.
                                       16

         IN WITNESS WHEREOF, ARIZONA PUBLIC SERVICE COMPANY, party hereto of the
first  part,  has caused its  corporate  name to be hereunto  affixed,  and this
instrument to be signed and sealed by its President, one of its Vice Presidents,
or its Treasurer,  and its corporate seal to be attested by its Secretary or one
of its Assistant  Secretaries or Associate Secretaries for and in its behalf, in
the City of  Phoenix,  Arizona,  and THE BANK OF NEW YORK,  party  hereto of the
second part,  has caused its  corporate  name to be hereunto  affixed,  and this
instrument  to be signed and sealed by one of its Vice  Presidents  or Assistant
Vice  Presidents  and its corporate  seal to be attested by one of its Assistant
Vice  Presidents or Assistant  Treasurers for and in its behalf,  in the City of
New York, New York, all as of the 1st day of April, 1997.

                                              ARIZONA PUBLIC SERVICE COMPANY

                                                      Nancy E. Felker
                                              ------------------------------
                                                         Treasurer

Attest:

Betsy A. Pregulman
- --------------------------------------
       Associate Secretary

Executed, sealed and delivered by 
  ARIZONA PUBLIC SERVICE COMPANY 
  in the presence of:

Brenda M. Kucharek
- --------------------------------------
Brenda M. Kucharek

Marie A. Papietro                                        [SEAL]
- --------------------------------------
Marie A. Papietro

                                               THE BANK OF NEW YORK, As Trustee

                                                        Walter N. Gitlin
                                               ---------------------------------
                                                         Vice President
Attest:

Stephen Giurlando
- --------------------------------------
     Assistant Vice President

Executed, sealed and delivered by 
  THE BANK OF NEW YORK in the 
  presence of:

Laura Mullen
- --------------------------------------
Laura Mullen
                                                            [SEAL]
Jason Gregory
- --------------------------------------
Jason Gregory
                                       17

STATE OF ARIZONA                    )
                                    )  ss.:
COUNTY OF MARICOPA                  )

         On this  9th  day of  April,  1997,  before  me,  Maria R.  Marrs,  the
undersigned  officer,  personally  appeared  Nancy E. Felker,  who  acknowledged
herself  to be the  Treasurer  of ARIZONA  PUBLIC  SERVICE  COMPANY,  an Arizona
corporation, and that she, as such Treasurer being authorized so to do, executed
the foregoing instrument for the purposes therein contained, by signing the name
of the corporation by herself as Treasurer.

         IN WITNESS WHEREOF, I have hereunto set my hand and seal.

                                                      Maria R. Marrs
                                       -----------------------------------------
                                                     Notary Public

                                       My Commission Expires     July 21, 1998
[SEAL]                                                       -------------------

STATE OF ARIZONA                    )
                                    )  ss.:
COUNTY OF MARICOPA                  )

         On this  9th day of  April,  1997,  before  me,  Maria  R.  Marrs,  the
undersigned officer,  personally came Nancy E. Felker, to me known, who being by
me duly sworn, did depose and say that she resides in Phoenix, Arizona, that she
is the Treasurer of ARIZONA PUBLIC SERVICE COMPANY, the corporation described in
and  which  executed  the  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 order of the Board of Directors  of said  corporation,
and that she signed her name thereto by like order.

         IN WITNESS WHEREOF, I have hereunto set my hand and seal.

                                                 Maria R. Marrs
                                       -----------------------------------------
                                                  Notary Public

                                       My Commission Expires     July 21, 1998
[SEAL]                                                       -------------------

STATE OF ARIZONA                    )
                                    ) ss.:
COUNTY OF MARICOPA                  )

         This instrument was acknowledged before me on April 9, 1997 by Nancy E.
Felker  and  Betsy  A.   Pregulman,   as  Treasurer  and  Associate   Secretary,
respectively, of ARIZONA PUBLIC SERVICE COMPANY.

                                                 Maria R. Marrs
                                       -----------------------------------------
                                                  Notary Public                 
                                                                                
                                       My Commission Expires     July 21, 1998  
[SEAL]                                                       -------------------
                                       18

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

         On this 8th day of April,  1997, before me, William J. Cassels,  Notary
Public  in and for the  County  and  State  aforesaid,  residing  therein,  duly
commissioned and sworn,  personally appeared Walter N. Gitlin, known to me to be
a Vice  President of THE BANK OF NEW YORK, New York banking  corporation,  which
executed the within  instrument,  and Stephen J.  Giurlando  known to me to be a
Assistant  Vice  President of The Bank of New York,  who being by me duly sworn,
acknowledged before me that the seal affixed to said instrument is the corporate
seal of The Bank of New York, that they, being authorized so to do, executed the
within instrument on behalf of The Bank of New York by authority of its board of
directors,  and that said instrument is the free act and deed of The Bank of New
York for the purposes therein contained.

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

                                               William J. Cassels
                                       -----------------------------------------
                                                  Notary Public                 
                                                                                
                                       My Commission Expires     May  16, 1998  
[SEAL]                                                       -------------------

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

         This instrument was  acknowledged  before me on April 8, 1997 by Walter
N.  Gitlin  and  Stephen J.  Giurlando  as Vice  President  and  Assistant  Vice
President, respectively, of THE BANK OF NEW YORK.


                                               William J. Cassels
                                       -----------------------------------------
                                                  Notary Public                 
                                                                                
                                       My Commission Expires     May  16, 1998  
[SEAL]                                                       -------------------