EXHIBIT 4.8.1(b)

                                                      Upon recording, return to:
                                                            Ms. Shawne M. Keenan
                                                Sutherland, Asbill & Brennan LLP
                                                      999 Peachtree Street, N.E.
                                                     Atlanta, Georgia 30309-3996

   PURSUANT TO Section 44-14-35.1 OF OFFICIAL CODE OF GEORGIA ANNOTATED, THIS
    INSTRUMENT EMBRACES, COVERS AND CONVEYS SECURITY TITLE TO AFTER-ACQUIRED
                           PROPERTY OF THE GRANTOR


================================================================================
================================================================================

                             OGLETHORPE POWER CORPORATION
                        (AN ELECTRIC MEMBERSHIP CORPORATION),
                                       GRANTOR,

                                          to

                               SUNTRUST BANK, ATLANTA,
                                       TRUSTEE



                                 FIRST SUPPLEMENTAL 
                                      INDENTURE


                                   Relating to the
                               Series 1997B (Burke) Note


                             Dated as of October 1, 1997



                              FIRST MORTGAGE OBLIGATIONS

================================================================================
================================================================================


                                                                                
                                                                                
                                           
    THIS FIRST SUPPLEMENTAL INDENTURE, dated as of October 1, 1997, is between
OGLETHORPE POWER CORPORATION (AN ELECTRIC MEMBERSHIP CORPORATION), an electric
membership corporation organized and existing under the laws of the State of
Georgia, as Grantor (hereinafter called the "Company"), and SUNTRUST BANK,
ATLANTA, a banking corporation organized and existing under the laws of the
State of Georgia, as Trustee (in such capacity, the "Trustee").

    WHEREAS, the Company has heretofore executed and delivered to the Trustee
an Indenture, dated as of March 1, 1997 (hereinafter called the "Original
Indenture") for the purpose of securing its Existing Obligations and providing
for the authentication and delivery of Additional Obligations by the Trustee
from time to time under the Original Indenture (capitalized terms used herein
shall have the meanings ascribed to them in the Original Indenture as provided
in Section 2.1 hereof);

    WHEREAS, the Development Authority of Burke County (the "Burke Authority")
issued  $216,925,000 in aggregate principal amount of Development Authority of
Burke County Pollution Control Revenue Bonds (Oglethorpe Power Corporation
Vogtle Project), Series 1997A (the "Series 1997A Bonds"), which mature on
December 1, 1997;

    WHEREAS, the Burke Authority loaned the proceeds from the sale of the
Series 1997A Bonds to the Company, with such loan being evidenced by that
certain Series 1997A Note, dated as of March 1, 1997 (the "Series 1997A Note"),
from the Company to SunTrust Bank, Atlanta, as trustee (in such capacity, the
"Series 1997A Trustee"), as assignee and pledgee of the Burke Authority pursuant
to the Trust Indenture, dated as of April 1, 1992, as supplemented by the First
Supplemental Indenture, dated as of March 1, 1997 (the "Series 1997A Indenture),
between the Burke Authority and the Series 1997A Trustee;

    WHEREAS, the Burke Authority intends to issue $216,925,000 in aggregate
principal amount of Development Burke Authority of Burke County Pollution
Control Revenue Bonds (Oglethorpe Power Corporation Vogtle Project), Series
1997B (the "Series 1997B Bonds"), the proceeds from the sale of which will be
loaned to the Company to refund the Series 1997A Bonds and pay the Series 1997A
Note;

    WHEREAS, the Company's obligation to repay the loan of the proceeds of the
Series 1997B Bonds will be evidenced by that certain Series 1997B (Burke) Note,
dated as of October 1, 1997 (the "Series 1997B (Burke) Note"), from the Company
to SunTrust Bank, Atlanta, as trustee (in such capacity, the "Series 1997B 
Trustee"), as assignee and pledgee of the Burke Authority pursuant to the Trust
Indenture, dated as of October 1, 1997 (the "Series 1997B Indenture"), between
the Burke Authority and the Series 1997B Trustee;

    WHEREAS, the Company desires to execute and deliver this First Supplemental
Indenture, in accordance with the provisions of the Original Indenture, for the
purpose of providing for the creation and designation of the Series 1997B
(Burke) Note as an Additional Obligation and specifying



the form and provisions of the Series 1997B (Burke) Note (the Original 
Indenture, as hereby supplemented and modified, being herein sometimes called 
the "Indenture"); 

    WHEREAS, Section 12.1 of the Original Indenture provides that, without the
consent of the Holders of any of the Obligations at the time Outstanding, the
Company, when authorized by a Board Resolution, and the Trustee, may enter into
supplemental indentures for the purposes and subject to the conditions set forth
in said Section 12.1; and

    WHEREAS, all acts and proceedings required by law and by the Articles of
Incorporation and Bylaws of the Company necessary to secure the payment of the
principal of (and premium, if any) and interest on the Series 1997B (Burke)
Note, to make the Series 1997B (Burke) Note to be issued hereunder, when
executed by the Company, authenticated and delivered by the Trustee and duly
issued, the valid, binding and legal obligation of the Company, and to
constitute the Indenture a valid and binding lien for the security of the Series
1997B (Burke) Note, in accordance with its terms, have been done and taken; and
the execution and delivery of this First Supplemental Indenture has been in all
respects duly authorized;

    NOW, THEREFORE, THIS FIRST SUPPLEMENTAL INDENTURE WITNESSES, that, to
secure the payment of the principal of (and premium, if any) and interest on the
Outstanding Secured Obligations, including, when issued, the Series 1997B
(Burke) Note, to confirm the lien of the Indenture upon the Trust Estate,
including property purchased, constructed or otherwise acquired by the Company
since the date of execution of the Original Indenture, to secure performance of
the covenants therein and herein contained, to declare the terms and conditions
on which the Series 1997B (Burke) Note is secured, and in consideration of the
premises thereof and hereof, the Company by these presents does grant, bargain,
sell, alienate, remise, release, convey, assign, transfer, mortgage,
hypothecate, pledge, set over and confirm to the Trustee, in trust, all
property, rights, privileges and franchises (other than Excepted Property or
Excludable Property) of the Company of the character described in the Granting
Clauses of the Original Indenture, including all such property, rights,
privileges and franchises acquired since the date of execution of the Original
Indenture, including, without limitation, all property described in EXHIBIT A
attached hereto, subject to all exceptions, reservations and matters of the
character therein referred to, and subject in all cases to Sections 5.2 and 11.2
B of the Original Indenture and to the rights of the Company under the Original
Indenture, including the rights set forth in Article V thereof; but expressly
excepting and excluding from the lien and operation of the Indenture all
properties of the character specifically excepted as "Excepted Property" or
"Excludable Property" in the Original Indenture to the extent contemplated
thereby.

    PROVIDED, HOWEVER, that if, upon the occurrence of an Event of Default
under the Original Indenture, the Trustee, or any separate trustee or co-trustee
appointed under Section 9.14 of the Original Indenture or any receiver appointed
pursuant to statutory provision or order of court, shall have entered into
possession of all or substantially all of the Trust Estate, all the Excepted
Property described or referred to in Paragraphs A through H, inclusive, of
"Excepted Property" in the Original Indenture then owned or thereafter acquired
by the Company, shall immediately, and, 


                                        3


in the case of any Excepted Property described or referred to in Paragraphs 
I, J, L, N and P of "Excepted Property" in the Original Indenture (excluding 
the property described in Section 2 of EXHIBIT B in the Original Indenture), 
upon demand of the Trustee or such other trustee or receiver, become subject 
to the lien of the Indenture to the extent permitted by law, and the Trustee 
or such other trustee or receiver may, to the extent permitted by law, at the 
same time likewise take possession thereof, and whenever all Events of 
Default shall have been cured and the possession of all or substantially all 
of the Trust Estate shall have been restored to the Company, such Excepted 
Property shall again be excepted and excluded from the lien of the Indenture 
to the extent and otherwise as hereinabove set forth and as set forth in the 
Original Indenture.

    The Company may, however, pursuant to the Third Granting Clause of the
Original Indenture, subject to the lien of the Indenture any Excepted Property
or Excludable Property, whereupon the same shall cease to be Excepted Property
or Excludable Property.

    TO HAVE AND TO HOLD all such property, rights, privileges and franchises
hereby and hereafter (by Supplemental Indenture or otherwise) granted,
bargained, sold, alienated, remised, released, conveyed, assigned, transferred,
mortgaged, hypothecated, pledged, set over or confirmed as aforesaid, or
intended, agreed or covenanted so to be, together with all the tenements,
hereditaments and appurtenances thereto appertaining (said properties, rights,
privileges and franchises, including any cash and securities hereafter deposited
or required to be deposited with the Trustee (other than any such cash which is
specifically stated in the Original Indenture not to be deemed part of the Trust
Estate) being part of the Trust Estate), unto the Trustee, and its successors
and assigns in the trust herein created, forever.

    SUBJECT, HOWEVER, to (i) Permitted Exceptions (as defined in Section 1.1 of
the Original Indenture) and (ii) to the extent permitted by Section 13.6 of the
Original Indenture as to property hereafter acquired (a) any duly recorded or
perfected prior mortgage or other lien that may exist thereon at the date of the
acquisition thereof by the Company and (b) purchase money mortgages, other
purchase money liens, chattel mortgages, conditional sales agreements or other
title retention agreements created by the Company at the time of acquisition
thereof.

    BUT IN TRUST, NEVERTHELESS, with power of sale, for the equal and
proportionate benefit and security of the Holders from time to time of all the
Outstanding Secured Obligations without any priority of any such Obligation over
any other such Obligation and for the enforcement of the payment of such
Obligations in accordance with their terms.

    UPON CONDITION that, until the happening of an Event of  Default and
subject to the provisions of Article V of the Original Indenture, and not in
limitation of the rights elsewhere provided in the Original Indenture, including
the rights set forth in Article V of the Original Indenture, the Company shall
be permitted to (i) possess and use the Trust Estate, except cash, securities,
Designated Qualifying Securities and other personal property deposited, or
required to be deposited, with the Trustee, (ii) explore for, mine, extract,
separate and dispose of coal, ore, gas, oil and other


                                        4


minerals, and harvest standing timber, and (iii) receive and use the rents, 
issues, profits, revenues and other income, products and proceeds of the 
Trust Estate.

    THE ORIGINAL INDENTURE, AS SUPPLEMENTED BY THIS FIRST SUPPLEMENTAL
INDENTURE, is intended to operate and is to be construed as a deed passing title
to the Trust Estate and is made under the provisions of the existing laws of the
State of Georgia relating to deeds to secure debt, and not as a mortgage or deed
of trust, and is given to secure the Outstanding Secured Obligations.  Should
the indebtedness secured by the Indenture be paid according to the tenor and
effect thereof when the same shall become due and payable and should the Company
perform all covenants herein contained in a timely manner, then the Indenture
shall be canceled and surrendered.

    AND IT IS HEREBY COVENANTED AND DECLARED that the Series 1997B (Burke) Note
is to be authenticated and delivered and the Trust Estate is to be held and
applied by the Trustee, subject to the covenants, conditions and trusts set
forth herein and in the Original Indenture, and the Company does hereby covenant
and agree to and with the Trustee, for the equal and proportionate benefit of
all Holders of the Outstanding Secured Obligations, as follows:


                                      ARTICLE I

                          THE SERIES 1997B (BURKE) NOTE AND
                         CERTAIN PROVISIONS RELATING THERETO

    SECTION 1.1    AUTHORIZATION AND TERMS OF THE SERIES 1997B (BURKE) NOTE.

    There shall be established an Additional Obligation in the form of a
promissory note known as and entitled the  "Series 1997B (Burke) Note"
(hereinafter referred to as the "Series 1997B (Burke) Note"), the form, terms
and conditions of which shall be substantially as set forth in this Section and
Section 1.2.  The aggregate principal face amount of the Series 1997B (Burke)
Note which shall be authenticated and delivered and Outstanding at any one time
is limited to $216,925,000.

    The Series 1997B (Burke) Note shall be dated as of October 1, 1997.  The
Series 1997B (Burke) Note shall bear interest at a rate of 3.80% from the date
of its authentication to the date of its maturity, payable on or before the
business day next preceding May 28, 1998 and shall mature on May 28, 1998.  The
Series 1997B (Burke) Note shall be authenticated and delivered to, and made
payable to, SunTrust Bank, Atlanta, as trustee (in such capacity, the "Series
1997B Trustee"), as assignee and pledgee of the Development Authority of Burke
County (the "Burke Authority") pursuant to the Series 1997B Indenture.


                                        5


    All payments made on the Series 1997B (Burke) Note shall be made to the
Series 1997B Trustee at its principal office in Atlanta, Georgia in lawful money
of the United States of America which will be immediately available on the date
payment is due.  

    SECTION 1.2  FORM OF THE SERIES 1997B (BURKE) NOTE.

    The Series 1997B (Burke) Note and the Series 1997B Trustee's authentication
certificate to be executed on the Series 1997B (Burke) Note shall be
substantially in the form of Exhibit B attached hereto, with such appropriate
insertions, omissions, substitutions and other variations as are required or
permitted in the Original Indenture.

    SECTION 1.3 USE OF PROCEEDS.

    The Company shall use the proceeds of the loan evidenced by the Series
1997B (Burke) Note to pay the Series 1997A Note.


                                      ARTICLE II

                                    MISCELLANEOUS

    SECTION 2.1    The First Supplemental Indenture is executed and shall be
construed as an indenture supplemental to the Original Indenture, and shall form
a part thereof, and the Original Indenture, as heretofore supplemented and as
hereby supplemented and modified, is hereby confirmed.  Except to the extent
inconsistent with the express terms hereof, all of the provisions, terms,
covenants and conditions of the Original Indenture shall be applicable to the
Series 1997B (Burke) Note to the same extent as if specifically set forth
herein.  All capitalized terms used in this First Supplemental Indenture shall
have the same meanings ascribed to them in the Original Indenture, except in
cases where the context clearly indicates otherwise.
    
    SECTION 2.2    All recitals in this First Supplemental Indenture are made
by the Company only and not by the Trustee; and all of the provisions contained
in the Original Indenture, in respect of the rights, privileges, immunities,
powers and duties of the Trustee shall be applicable in respect hereof as fully
and with like effect as if set forth herein in full.

    SECTION 2.3    Whenever in this First Supplemental Indenture any of the
parties hereto is named or referred to, this shall, subject to the provisions of
Articles IX and XI of the Original Indenture, be deemed to include the
successors and assigns of such party, and all the covenants and agreements in
this First 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.


                                        6


    SECTION 2.4    Nothing in this First 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 Outstanding Secured Obligations, any right, remedy or claim under or by
reason of this First Supplemental Indenture or any covenant, condition,
stipulation, promise or agreement hereof, and all the covenants, conditions,
stipulations, promises and agreements in this First 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 Outstanding Secured
Obligations.

    SECTION 2.5    This First Supplemental Indenture may be executed in several
counterparts, each of such counterparts shall for all purposes be deemed to be
an original, and all such counterparts, or as many of them as the Company and
the Trustee shall preserve undestroyed, shall together constitute but one and
the same instrument.

    SECTION 2.6    To the extent permitted by applicable law, this First
Supplemental Indenture shall be deemed to be a Security Agreement and Financing
Statement whereby the Company grants to the Trustee a security interest in all
of the Trust Estate that is personal property or fixtures under the Uniform
Commercial Code, as adopted or hereafter adopted in one or more of the states in
which any part of the properties of the Company are situated.  The mailing
address of the Company,

as debtor is:      2100 East Exchange Place 
                   P. O. Box 1349 
                   Tucker, Georgia 30085-1349, 

and the mailing address of the Trustees, as secured party is:

                   SunTrust Bank, Atlanta, 
                   58 Edgewood Avenue, Room 400A
                   Atlanta, Georgia 30303








                              [Signatures on Next Page.]    


                                          7

    
    IN WITNESS WHEREOF, the parties hereto have caused this First Supplemental
Indenture to be duly executed under seal as of the day and year first above
written.

COMPANY:                          OGLETHORPE POWER 
                                  CORPORATION (AN ELECTRIC
                                  MEMBERSHIP CORPORATION), an electric
                                  membership corporation organized under the
                                  laws of the State of Georgia

2100 East Exchange Place
P. O. Box 1349
Tucker, Georgia 30085-1349

                                  By:  /s/ T. D. Kilgore 
                                     ------------------------------------------
                                       T. D. Kilgore
                                       President and Chief Executive Officer

Signed, sealed and delivered      Attest: /s/ Patricia N. Nash
by the Company in the presence           --------------------------------------
of:                                      Patricia N. Nash
                                         Secretary                  
/s/ T. A. Smith           
- ----------------------------------
Witness

/s/ Thomas J. Brendiar         
- ----------------------------------
Notary Public                                  [CORPORATE SEAL]                 

(Notarial Seal)

My commission expires:  Nov. 14, 2000       
                      ----------------------


                         [Signatures Continued on Next Page.] 



                      [Signatures Continued from Previous Page.]




TRUSTEE:                          SUNTRUST BANK, ATLANTA
                                  a banking corporation organized and existing
                                  under the laws of the State of Georgia


                                  By: /s/ Philip D. DeMouey          
                                     ------------------------------------------
Signed, sealed and delivered          Name: Philip D. DeMouey            
by the Trustee in the                 Title: Assistant Vice President    
presence of:
                   
                                  By: /s/ Antonio I. Portundo               
                                      -----------------------------------------
/s/ David McMahon                     Name:  Antonio I. Portundo       
- --------------------------------      Title: Vice President
Witness                                               


/s/ Teresa R. Turner        
- --------------------------------
Notary Public                                         [BANK SEAL]              

(Notarial Seal)

My commission expires: April 3, 2001    
                      ----------------------



                                      EXHIBIT A

    All property of the Company in the Counties of Appling, Ben Hill, Burke,
Carroll, Clarke, Cobb, DeKalb, Floyd, Fulton, Heard, Jackson, Monroe, and
Toombs, State of Georgia, including, without limitation, the properties more
specifically described below:

    No additional properties to be specifically described. 


                                          A-1


                                      EXHIBIT B


                         [Form of Series 1997B (Burke) Note]


THIS NOTE IS NON-TRANSFERABLE EXCEPT AS MAY BE REQUIRED TO EFFECT ANY TRANSFER
TO ANY SUCCESSOR TRUSTEE UNDER THE TRUST INDENTURE, DATED AS OF OCTOBER 1, 1997,
AS SUPPLEMENTED, BETWEEN THE DEVELOPMENT AUTHORITY OF BURKE COUNTY AND SUNTRUST
BANK, ATLANTA, AS TRUSTEE.

                             OGLETHORPE POWER CORPORATION
                         (AN ELECTRIC MEMBERSHIP CORPORATION)
                                           
                              SERIES 1997B (BURKE) NOTE
                                           
                                   (VOGTLE PROJECT)
                                           
    OGLETHORPE POWER CORPORATION (AN ELECTRIC MEMBERSHIP CORPORATION)
("Oglethorpe"), an electric membership corporation organized and existing under
the laws of the State of Georgia, for value received and in consideration of the
agreement of the Development Authority of Burke County (the "Burke Authority")
to issue $216,925,000 in aggregate principal amount of Development Authority of
Burke County Pollution Control Revenue Bonds (Oglethorpe Power Corporation
Vogtle Project), Series 1997B (the "Series 1997B Bonds"), hereby promises to pay
to SunTrust Bank, Atlanta (the "Series 1997B Trustee"), as assignee and pledgee
of the Burke Authority, acting pursuant to the Trust Indenture, dated as of
October 1, 1997, from the Burke Authority to the Series 1997B Trustee (the
"Series 1997B Indenture"), or its successor in trust, the principal sum of
$216,925,000, together with interest thereon as follows:

         (1)  on or before the business day next preceding May 28, 1998, a sum
which will equal the interest on the Series 1997B Bonds which will become due on
May 28, 1998; and

         (2)  on or before the business day next preceding May 28, 1998, a sum
which will equal the principal amount of the Series 1997B Bonds due on May 28,
1998.

    This Note is issued to evidence the Loan (as defined in the Agreement
hereinafter referred to) of the Burke Authority to Oglethorpe and the obligation
to repay the same and shall be governed by and shall be payable in accordance
with the terms, conditions and provisions of the Loan Agreement, dated as of
October 1, 1997 (the "Agreement"), between the Burke Authority and Oglethorpe,
pursuant to which the Burke Authority has agreed to loan to Oglethorpe the
proceeds from the sale of the Series 1997B Bonds.

                                         B-1



    This Note is a duly authorized obligation of Oglethorpe issued under and
equally and ratably secured by the Indenture, dated as of March 1, 1997 (the
"Original Mortgage Indenture"), between Oglethorpe, as grantor, and SunTrust
Bank, Atlanta, as trustee (in such capacity, the "Mortgage Indenture Trustee"),
as supplemented by the First Supplemental Indenture, dated as of October 1, 1997
(the "First Supplemental Indenture"), between Oglethorpe and the Mortgage
Indenture Trustee (the Original Mortgage Indenture, as supplemented, the
"Mortgage  Indenture").  Reference is hereby made to the Mortgage Indenture for
a statement of the description of the properties thereby mortgaged, pledged and
assigned, the nature and extent of the security and the respective rights,
limitations of rights, duties and immunities thereunder of Oglethorpe, the
Mortgage Indenture Trustee and the holder of this Note and of the terms upon
which this Note is authenticated and delivered.  This Note is created by the
First Supplemental Indenture and designated as the "Series 1997B (Burke) Note".

    All payments hereon are to be made to the Series 1997B Trustee at its
principal office in Atlanta, Georgia, in lawful money of the United States of
America which will be immediately available on the day payment is due.  As set
forth in Section 4.6 of the Agreement, the obligation of Oglethorpe to make the
payments required hereunder shall be absolute and unconditional.

    Oglethorpe shall be entitled to certain credits against payments required
to be made hereunder as provided in Section 4.3 of the Agreement.

    This Note may be prepaid upon the terms and conditions set forth in Article
VIII of the Agreement. 

    If the Series 1997B Trustee shall accelerate payment of the Series 1997B
Bonds, all payments on this Note shall be declared due and payable in the manner
and with the effect provided in the Agreement.  The Agreement provides that,
under certain conditions, such declaration shall be rescinded by the Series
1997B Trustee.

    No recourse shall be had for the payments required hereby or for any claim
based herein or in the Agreement or in the Mortgage Indenture against any
officer, director or member, past, present or future, of Oglethorpe as such,
either directly or through Oglethorpe, or under any constitution provision,
statute or rule of law or by the enforcement of any assessment or by any legal
or equitable proceedings or otherwise.

    This Note shall not be entitled to any benefit under the Mortgage Indenture
and shall not become valid or obligatory for any purposes until the Mortgage
Indenture Trustee shall have signed the form of authentication certificate
endorsed hereon.

                                         B-2



    IN WITNESS WHEREOF, Oglethorpe has caused this Note to be executed in its
corporate name by its President and Chief Executive Officer and attested by its
Secretary and its corporate seal to be hereunto affixed, all of the 1st day of
October, 1997.


                             OGLETHORPE POWER CORPORATION (AN
                             ELECTRIC MEMBERSHIP CORPORATION)


                             By:_____________________________________
                                  T. D. Kilgore
                                  President and Chief Executive Officer

(SEAL)


Attest:

_______________________________
Patricia N. Nash
Secretary



                                         ***



                       TRUSTEE'S CERTIFICATE OF AUTHENTICATION


    This is one of the Obligations of the series designated therein referred to
in the within mentioned Indenture.

                             SUNTRUST BANK, ATLANTA, as Trustee

                             By:_____________________________________
                                  Authorized Signatory


                                        B-3