Exhibit
4.30

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SECURITY
AGREEMENT

This is a
Security Agreement covering personal property as well as other property real
and/or personal

PUGET SOUND
ENERGY, INC.

TO

HARRIS
TRUST AND SAVINGS BANK,

TRUSTEE
________________

THIRTY-FIRST SUPPLEMENTAL INDENTURE

Dated as of
February 10, 1997

SUPPLEMENTING

INDENTURE
OF FIRST MORTGAGE

Dated as of
April 1, 1957

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SECURITY
AGREEMENT

This is a
Security Agreement covering personal property as well as other property
real and/or personal

THIRTY-FIRST SUPPLEMENTAL
INDENTURE dated as of February 10, 1997 (hereinafter called the
Thirty-first Supplemental Indenture) and made by and between PUGET SOUND
ENERGY, INC., a corporation organized and existing under the laws of the State
of Washington (hereinafter called the Company), as Debtor (its Federal
identification number being 91-0374630), whose mailing address and address of
its principal place of business is 411  108th Avenue N.E., Bellevue, Washington
98004, party of the first part and HARRIS TRUST AND SAVINGS BANK, as Trustee and
Secured Party (its Federal identification number being 36-1194448), a
corporation organized and existing under the laws of the State of Illinois and
having its principal place of business at 111 West Monroe Street, Chicago,
Illinois 60690 (hereinafter called theTrustee), party of the second part.

WHEREAS, Washington
Natural Gas Company, a corporation organized and existing under the laws of the
State of Delaware (hereinafter called the First Predecessor Company), which
was merged into Washington Natural Gas Company, a corporation organized and
existing under the laws of the State of Washington (hereinafter called the
Second Predecessor Company) on August 9, 1978, had heretofore executed
and delivered to the Trustee its Indenture of First Mortgage dated as of
April 1, 1957 (hereinafter called the Original Indenture or, as
heretofore supplemented and modified, hereinafter called the Indenture) in
order, among other things, to secure, as provided therein, the payment of the
principal of and premium, if any, and interest on its bonds (in the Indenture
and herein called the Bonds) at any time issued and outstanding thereunder
according to their tenor and effect, said Bonds to be designated generally as
its First Mortgage Bonds, and to be issued in one or more series as provided
in the Original Indenture; and

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WHEREAS, the First
Predecessor Company had heretofore executed and delivered sixteen indentures
supplemental to the Original Indenture as follows: First Supplemental Indenture,
dated as of April 1, 1957, naming and appointing, pursuant to the
provisions of Section 15.18 of the Original Indenture, R.H. Long, an
individual, to act as Co-Trustee jointly with the Trustee, Second Supplemental
Indenture dated as of October 1, 1959, Third Supplemental Indenture dated
as of May 1, 1961, Fourth Supplemental Indenture dated as of May 1,
1963, Fifth Supplemental Indenture dated as of June 1, 1965, Sixth
Supplemental Indenture dated as of August 1, 1966, Seventh Supplemental
Indenture dated as of February 1, 1967, Eighth Supplemental Indenture dated
as of September 1, 1967, Ninth Supplemental Indenture dated as of
September 1, 1968, Tenth Supplemental Indenture dated as of June 1,
1970, Eleventh Supplemental Indenture dated as of April 1, 1971, Twelfth
Supplemental Indenture dated as of November 1, 1972, Thirteenth
Supplemental Indenture dated as of September 1, 1975, Fourteenth
Supplemental Indenture dated as of September 15, 1975, Fifteenth
Supplemental Indenture dated as of March 1, 1977 and Sixteenth Supplemental
Indenture dated as of June 1, 1977, naming and appointing, pursuant to the
provisions of Section 15.18 of the Original Indenture, R.G. Mason, an
individual, to act as successor Co-Trustee, pursuant to each of which
supplemental indentures, except said First, Seventh, and Sixteenth Supplemental
Indentures, the First Predecessor Company provided for the creation of an issue
of First Mortgage Bonds, and said Sixth and Seventh Supplemental Indentures
provided for certain modifications of the Original Indenture; and

WHEREAS, the Second
Predecessor Company has heretofore executed and delivered a Seventeenth
Supplemental Indenture dated as of August 9, 1978, whereby the Second
Predecessor Company succeeded to the First Predecessor Company with the same
effect as if the Second Predecessor Company had been named in the Indenture as
the mortgagor company and in the Bonds and coupons as the obligor thereon or
maker thereof, and the First Predecessor Company merged into the Second
Predecessor Company on August 9, 1978 whereupon the Second Predecessor
Company acquired all the property, real, personal or mixed, including all
rights, privileges, immunities and franchises, described in the Indenture and
thereby conveyed and mortgaged or intended so to be, including also all such
property acquired by the First Predecessor Company since the execution and
delivery of the Original Indenture, which by the terms of the Indenture is
subject or intended to be subjected to the lien thereof; and

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WHEREAS, the Second
Predecessor Company has also heretofore executed and delivered an Eighteenth
Supplemental Indenture dated as of September 1, 1979, a Nineteenth
Supplemental Indenture dated as of January 15, 1982, a Twentieth
Supplemental Indenture dated as of August 15, 1983, a Twenty-first
Supplemental Indenture dated as of August 15, 1983, a Twenty-second
Supplemental Indenture dates as of July 15, 1986, a Twenty-third
Supplemental Indenture dated as of July 15, 1986, a Twenty-fourth
Supplemental Indenture dated as of December 15, 1987, a Twenty-fifth
Supplemental Indenture dated as of August 15, 1988, a Twenty-sixth
Supplemental Indenture dated as of September 1, 1990, a Twenty-seventh
Supplemental Indenture dated as of September 1, 1990, a Twenty-eighth
Supplemental Indenture dated as of July 1, 1991, a Twenty-ninth
Supplemental Indenture dated as of June 1, 1993 and a Thirtieth
Supplemental Indenture dated as of August 15, 1995 pursuant to each of
which supplemental indentures the Second Predecessor Company provided for the
creation of an issue of First Mortgage Bonds, and said Twenty-second and
Twenty-eighth Supplemental Indentures provided for certain modifications of the
Original Indenture; and

WHEREAS, R.G. Mason, the
successor Co-Trustee, resigned on July 31, 1993 and no successor trustee was
appointed to replace him; and

WHEREAS, pursuant to the
Original Indenture, as heretofore supplemented and modified, there have been
executed, authenticated, delivered and issued and there are now outstanding,
First Mortgage Bonds of series and in principal amounts as follows:

|                             |  |            |  |            
|---------------------------- |  | ---------- |  | -----------
|Title                        |  | Issued     |  | Outstanding
|                             |  |            |  |            
|8-1/8% Series due
      1997 |  | 6,000,000  |  | 2,920,000  
|                             |  |            |  |            
|9.60% Series due
      2000  |  | 25,000,000 |  | 25,000,000 
|                             |  |            |  |            
|9.57% Series due
      2020  |  | 25,000,000 |  | 25,000,000 

|                                     
|-------------------------------------
|Secured Medium Term Notes, Series A
-

|                                   |  |            |  |           
|---------------------------------- |  | ---------- |  | ----------
|8.25% due 1998                     |  | 11,000,000 |  | 11,000,000
|                                   |  |            |  |           
|7.08% due
      1999               |  | 10,000,000 |  | 10,000,000
|                                   |  |            |  |           
|8.51%
      through 8.55% due 2001 |  | 19,000,000 |  | 19,000,000
|                                   |  |            |  |           
|7.53% and
      7.91% due 2002     |  | 30,000,000 |  | 30,000,000
|                                   |  |            |  |           
|8.25%
      through 8.40%          |  | 35,000,000 |  | 35,000,000
|                                   |  |            |  |           

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|                                     
|-------------------------------------
|Secured Medium Term Notes, Series B
-

|                               |  |            |  |           
|------------------------------ |  | ---------- |  | ----------
|6.23% through 6.31% due 2003   |  | 28,000,000 |  | 28,000,000
|                               |  |            |  |           
|6.07% and
      6.10% due 2004 |  | 18,500,000 |  | 18,500,000
|                               |  |            |  |           
|6.51% and
      6.53% due 2008 |  | 4,500,000  |  | 4,500,000 
|                               |  |            |  |           
|6.83% and
      6.90% due 2013 |  | 13,000,000 |  | 13,000,000
|                               |  |            |  |           
|7.19% due
      2023           |  | 13,000,000 |  | 13,000,000
|                               |  |            |  |           

|                                     
|-------------------------------------
|Secured Medium Term Notes, Series C
-

|                               |  |            |  |           
|------------------------------ |  | ---------- |  | ----------
|6.92% and 6.93% due 2005       |  | 31,000,000 |  | 31,000,000
|                               |  |            |  |           
|6.58% due
      2006           |  | 10,000,000 |  | 10,000,000
|                               |  |            |  |           
|7.02% and
      7.04% due 2007 |  | 25,000,000 |  | 25,000,000
|                               |  |            |  |           
|6.61% and
      6.62% due 2009 |  | 8,000,000  |  | 8,000,000 
|                               |  |            |  |           
|7.12% due
      2010           |  | 7,000,000  |  | 7,000,000 
|                               |  |            |  |           
|7.35% and
      7.36% due 2015 |  | 12,000,000 |  | 12,000,000
|                               |  |            |  |           
|7.15% and
      7.20% due 2025 |  | 17,000,000 |  | 17,000,000
|                               |  |            |  |           

WHEREAS, on
February 10, 1997, the Second Predecessor Company was merged with and into
the Company, on such terms as in no respect to impair the lien and security of
the Indenture on the trust estate or any of the rights or powers of the Trustee
or of the bondholders thereunder, in a duly authorized statutory merger
(hereinafter called the Merger) effected in conformity with the applicable
laws of the State of Washington, and the Company is the surviving corporation
under the Merger; and

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WHEREAS, the Company has
delivered officers certificates and an opinion of counsel to the Trustee
pursuant to Section 14.07 establishing compliance with the conditions set forth
in Sections 14.01 to 14.04, inclusive; and

WHEREAS,
Section 14.01 of the Indenture provides that the Company as the surviving
corporation of the Merger shall prior to or contemporaneously with the Merger
execute, and promptly cause to be recorded, a supplemental indenture to and with
the Trustee, satisfactory to the Trustee, whereby the Company shall assume and
agree to pay duly and punctually the principal of and interest on the Bonds
issued under the Indenture in accordance with the provisions of said Bonds, and
any coupons appertaining thereto, and the Indenture, and shall, subject to the
provisions of Section 14.04 of the Indenture with respect to property of the
Company not subject to this Indenture, agree to perform and fulfill all of the
terms, covenants and conditions of the Indenture binding the Second Predecessor
Company in respect of the trust estate; and

WHEREAS,
Section 18.01 of the Indenture authorizes the Trustee to enter into an
Indenture with the Company supplemental to the Indenture for the purpose of
evidencing the succession of a successor corporation to the Second Predecessor
Company and the assumption by the Company (as such successor) of the covenants
and obligations of the Second Predecessor Company contained in the Bonds and in
the Indenture, and the Company is entering into this Thirty-first Supplemental
Indenture for such purpose, all the other conditions of the Indenture to the
Merger of the Second Predecessor Company into the Company (with the Company
surviving the Merger) having been satisfied; and

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WHEREAS, all conditions
and requirements necessary to make this Thirty-first Supplemental Indenture a
valid, binding and legal instrument have been done, performed and fulfilled, and
the execution and delivery thereof have been duly authorized in all respects;

NOW,
THEREFORE:

For the purpose mentioned
in the recitals above, and in consideration of the premises and of the mutual
covenants and agreements herein and of the sum of Ten Dollars ($10.00) to the
Company duly paid by the Trustee, the receipt whereof is hereby acknowledged,
the Company and the Trustee covenant and agree as follows:

1.01 The Company hereby
assumes and agrees to pay duly and punctually the principal of and interest on
all of the Bonds heretofore issued under the Indenture and outstanding at the
time of the merger and on all Bonds which may be hereafter issued under the
Indenture, in accordance with the provisions of said Bonds, and any coupons
appertaining thereto, and of the Indenture, and, subject to the provisions of
Section 14.04 of the Indenture with respect to property of the Company not
subject to this Indenture, agrees to perform and fulfill all the terms,
covenants and conditions of the Indenture binding upon the Second Predecessor
Company in respect of the trust estate. The Company does hereby represent and
warrant that there does not now exist any default under the Indenture or any
condition or event which, with the passage of time or notice or both, would
become a default thereunder.

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1.02 The Second
Predecessor Company has been merged with and into the Company on such terms as
in no respect to impair the lien and security of the Indenture on the trust
estate or any of the rights or powers of the Trustee or of the bondholders
thereunder. The Company shall succeed to and become substituted for the Second
Predecessor Company in the Indenture with the same effect as if it had been
named therein as the mortgagor and in the Bonds and coupons as the obligor
thereon or maker thereof. Hereafter the Company may cause to be signed, issued
and delivered in its own name any or all such Bonds, and upon the application of
the Company, and subject to all the terms, conditions and restrictions in the
Indenture prescribed with respect to the authentication and delivery of Bonds,
the Trustee shall authenticate and deliver any of such Bonds which the Company
shall hereafter, in accordance with the provisions of the Indenture, cause to be
signed by its appropriate officers and delivered to the Trustee for such
purpose. All the Bonds so issued shall in all respects have the same legal rank
and security as the Bonds heretofore or hereafter issued in accordance with the
terms of the Indenture as though all of said bonds had been issued at the date
of the execution of the Original Indenture.

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1.03 It is hereby
declared that, in accordance with the provisions of Section 14.04 of the
Indenture, the Indenture (as further modified by this Thirty-first Supplemental
Indenture) shall not become or be a lien upon any of the property of the Company
and/or of property hereafter acquired by the Company, except (a) the gas
utility property (as defined in Section 1.27 of the Indenture) acquired by the
Company from the Second Predecessor Company in the Merger, and substitutions,
replacements, additions, betterments, developments, extensions and enlargements
to, of or upon such gas utility property, and (b) any other property of the
Company hereafter expressly made subject to the lien of the Indenture by
supplemental indenture.

1.04 In respect of
property owned by the Second Predecessor Company at the time of the Merger, and
substitutions, replacements, additions, betterments, developments, extensions
and enlargements thereto subsequently made, constructed or acquired, the rights
and duties of the Company as the successor corporation under the Indenture shall
be the same as the rights and duties of the Second Predecessor Company would
have been had the Merger not taken place. The excepted property described in
Clause IX of the Granting Clauses of the Indenture shall continue to be
expressly excepted and excluded from the lien and operation of the Indenture.

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1.05 The Company as the
successor corporation in the Merger shall keep its accounts so that earnings of
the trust estate subject to the Indenture may at all times be distinguished and
all covenants contained in the Indenture affecting the trust estate shall be
fully performed and to that end there shall be made appropriate allocations of
earnings and expenses as between those applicable to such trust estate and those
applicable to properties of the Company which have not become part of such trust
estate.

1.06 Subject to any
amendments provided for in this Thirty-first Supplemental Indenture, the terms
defined in the Indenture shall, for all purposes of this Thirty-first Supplement
Indenture, have the meanings specified in the Indenture.

1.07 The recitals in the
preamble to this Thirty-first Supplemental Indenture shall be taken as the
statements of the Company and the Trustee assumes no responsibility for the
correctness of the same.

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

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IN WITNESS WHEREOF, PUGET
SOUND ENERGY, INC., a Washington corporation, has caused this Thirty-first
Supplemental Indenture to be signed in its corporate name and behalf by its
President or one of its Vice Presidents and its corporate seal to be hereunto
affixed and attested by its Secretary or an Assistant Secretary, and HARRIS
TRUST AND SAVINGS BANK has caused this Thirty-first Supplemental Indenture to be
signed in its corporate name and behalf by its President or one of its Vice
Presidents and its corporate seal to be hereunto affixed and attested by its
Secretary or an Assistant Secretary, on the dates of their respective
acknowledgments but effective as of the day and year first above written.

| |                                 
| | --------------------------------
| | PUGET
      SOUND ENERGY, INC.  
| | (a Washington
      corporation)
| |                                 
| | By_______________________       
| | Title:_____________________     

| |                         
| | ------------------------
| | ________________________
| | Secretary               

| |                                    
| | -----------------------------------
| | HARRIS
      TRUST AND SAVINGS BANK
| | as
  Trustee                       
| |                                    
| | By_______________________          
| | Vice
      President               

| |                         
| | ------------------------
| | ________________________
| | Assistant Secretary     

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|                          |      
|------------------------- | -----
|STATE OF
      WASHINGTON | )    
|                          | ) ss.
|COUNTY OF
    KING        | )    

I certify that I know or
have satisfactory evidence that _______________ and ___________________ are the
persons who appeared before me, and said persons acknowledged that they signed
this instrument, on oath stated that they were authorized to execute the
instrument and acknowledged it as the _____________ and Secretary, respectively,
of Puget Sound Energy, Inc., to be the free and voluntary act of such party for
the uses and purposes mentioned in the instrument.
           DATED:
_________________, 1997.

|                      |                                              
|--------------------- | ---------------------------------------------
|(Seal or
      stamp) | __________________________________           
|                      | Notary
      Signature                       
|                      |                                              
|                      | __________________________________           
|                      | Print/Type
      Name_____________________   
|                      | Notary Public in and
      for the State of  
|                      | Washington, residing
      at _______________
|                      | __________________________________           
|                      | My appointment
      expires _______________ 
|                      |                                              

|                        |      
|----------------------- | -----
|STATE OF
      ILLINOIS | )    
|                        | ) ss.
|COUNTY OF
    COOK      | )    

I certify that I know or
have satisfactory evidence that ____________________ and __________________ are
the persons who appeared before me, and said persons authorized to execute the
instrument and acknowledged it as the Vice President and Assistant Secretary,
respectively, of Harris Trust and Savings bank, to be the free and voluntary act
of such party for the uses and purposes mentioned in the instrument.
           DATED:
_________________, 1997.

|                      |                                              
|--------------------- | ---------------------------------------------
|(Seal or
      stamp) | __________________________________           
|                      | Notary
      Signature                       
|                      |                                              
|                      | __________________________________           
|                      | Print/Type
      Name_____________________   
|                      | Notary Public in and
      for the State of  
|                      | Washington, residing
      at _______________
|                      | __________________________________           
|                      | My appointment
      expires _______________ 
|                      |                                              

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