EXHIBIT 4.1.3

                          SECOND SUPPLEMENTAL INDENTURE

                           Dated as of April 26, 2004

                                     Between

                              CALPINE CORPORATION,

                                    AS ISSUER

                                       and

                         U.S. BANK NATIONAL ASSOCIATION
                (successor trustee to State Street Bank and Trust
                                    Company,
                    successor trustee to Fleet National Bank)

                           Supplementing the Indenture
                            Dated as of May 16, 1996
                                       and
                          Amended as of August 1, 2000





     SECOND   SUPPLEMENTAL   INDENTURE,   dated  as  of  April  26,   2004  (the
"Supplemental  Indenture"),  between Calpine Corporation, a Delaware corporation
(the  "Company"),  and  U.S.  Bank  National  Association  (the  "Trustee"),  as
successor  trustee to State Street Bank and Trust Company,  successor trustee to
Fleet National Bank.

     WHEREAS,  the Company  executed and delivered the Indenture dated as of May
16, 1996,  as  supplemented  by the First  Supplemental  Indenture,  dated as of
August 1, 2000 (as so supplemented,  the "Indenture"), to the predecessor of the
Trustee's  predecessor  to  provide  for the  issuance  of  $180,000,000  of the
Company's 10-1/2% Senior Notes due 2006;

     WHEREAS  the  Holders  (as  defined  in the  Indenture)  of a  majority  in
principal  amount  outstanding  of  such  Senior  Notes  have  approved  certain
amendments  proposed by the Company to certain provisions of the Indenture,  and
the  Company  desires  to  supplement  and amend the  Indenture  accordingly  as
contemplated by Section 8.2 thereof; and

     WHEREAS,  all things necessary to make this Supplemental  Indenture a valid
agreement  of the  Company and the  Trustee in  accordance  with its terms and a
valid amendment and supplement to the Indenture, have been done.

     NOW  THEREFORE,  for  and in  consideration  of  the  premises  and  mutual
covenants herein contained, the Company and the Trustee agree as follows:

                                    ARTICLE I
                                   DEFINITIONS

     Section 1.1 Definition of Terms.

     Unless the context otherwise requires

     (a)  capitalized  terms used herein that are not otherwise  defined  herein
shall have the meanings assigned to such terms in the Indenture;

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

     (c)  headings  are for  convenience  of  reference  only and do not  affect
interpretation.

                                   ARTICLE II
                             AMENDMENTS TO INDENTURE

     Section 2.1 Amendments.

     (a) The following  definitions  are added in the  appropriate  alphabetical
order to Section 1.1 of the Indenture:

          "Designated  Assets" means all geothermal energy assets (including any
     related  extraction  processing or similar  equipment and geothermal  power
     plants)



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     and all natural gas assets (including any related extraction, processing or
     similar  equipment,  other  than  natural  gas power  plants)  owned by the
     Company or any of its Restricted  Subsidiaries from time to time, including
     the equity  interests of any  Restricted  Subsidiary  owning any Designated
     Assets,  but  excluding  (i) any  geothermal  energy  assets  that are both
     unproven and  undeveloped  and (ii)  contracts  for the purchase or sale of
     natural gas and natural gas supplied under such contracts.

          "Fair  Market  Value"  means the value that would be paid by a willing
     buyer to a willing  seller  in a  transaction  not  involving  distress  or
     necessity  of  either  party,  determined  in good  faith  by the  Board of
     Directors (unless otherwise provided in this Indenture).

          "Material  Designated  Assets" means  Designated  Assets having a Fair
     Market Value in the aggregate in excess of $50,000,000.

     (b) The  definition of "Preferred  Stock" in Section 1.1 is amended to read
in its entirety as follows:

          "Preferred  Stock", as applied to the Capital Stock of any corporation
     or other Person,  means the Capital Stock of any class (however designated)
     which  is  preferred  as  to  the  payment  of  dividends,  or  as  to  the
     distribution  of assets upon any voluntary or  involuntary  liquidation  or
     dissolution  of such  corporation  or other Person,  over shares of Capital
     stock of any other class of such corporation or other Person.

     (c) Section  3.3(b) is amended by (i) deleting the word "and" at the end of
clause  (iv),  (ii)  deleting  the  period  (".") at the end of  clause  (v) and
replacing it with a semicolon (";"),  (iii) inserting the word "and" immediately
after the  semicolon at the end of clause (v); and (iv)  inserting the following
immediately after such word "and":

          (vi) the payment of any dividend  (or, in the case of any  partnership
     or limited  liability  company,  any similar  distribution) by a Restricted
     Subsidiary  of the  Company  to the  holders of any class or series of such
     Restricted Subsidiary's Capital Stock on a pro rata basis.

     (d) Section  3.4(b) is amended by (i) deleting the word "and" at the end of
clause  (ix),  (ii)  deleting  the  period  (".") at the end of  clause  (x) and
replacing it with a semicolon (";"),  (iii) inserting the word "and" immediately
after the  semicolon at the end of clause (x); and (iv)  inserting the following
immediately after such word "and":

          (xi) the issuance of Preferred Stock by a Restricted Subsidiary of the
     Company  (other  than  a  Restricted  Subsidiary  that  owns,  directly  or
     indirectly,  any Material Designated Assets), the net proceeds of which are
     applied to finance the exploration, drilling, development,  construction or
     purchase of or by, or repairs or



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     improvements  or  additions  to,  property  or assets of the Company or any
     Restricted Subsidiary.

     (e) Section 3.5(c) is amended to read in its entirety as follows:

          (c) Refinancing Indebtedness; provided that the restrictions contained
     in  the  agreements   governing  such  Refinancing   Indebtedness  are  not
     materially more restrictive,  taken as a whole, than those contained in the
     agreements governing the Indebtedness being refinanced;

     (f) Section 3.5(d) is amended to read in its entirety:

          (d) in the  case  of  clause  (iii)  above,  customary  non-assignment
     provisions  of (A) any leases  governing  a  leasehold  interest or (B) any
     supply,  license or other agreement  entered into in the ordinary course of
     business of the Company or any Subsidiary;

     (g) Section 3.5(f) is amended to read in its entirety:

          (f) any  encumbrance or restriction  imposed  pursuant to the terms of
     any Indebtedness  incurred pursuant to Section 3.4(b)(vii) or any Preferred
     Stock issued pursuant to Section 3.4(b)(xi), provided that such encumbrance
     or  restriction,  in the written  opinion of the President,  Vice Chairman,
     Chief Operating Officer or Chief Financial  Officer of the Company,  (x) is
     required  in order to obtain  such  financing  or to place  such  Preferred
     Stock,  (y) is customary for such  financings or placements and (z) applies
     only to the assets or revenues of the applicable Restricted Subsidiary;

     (h) Section 3.5 is amended by (i)  deleting  the period (".") at the end of
clause (g) and  replacing  it with a semicolon  (";"),  and (ii)  inserting  the
following immediately after such new semicolon:

          (h) Liens  securing  Indebtedness  otherwise  permitted to be incurred
     under the  provisions  of Section  3.7  herein  that limit the right of the
     debtor to dispose of the assets subject to such Liens;

          (i) provisions limiting or prohibiting the disposition or distribution
     of assets or property in joint venture  agreements,  asset sale agreements,
     sale-leaseback   agreements,   stock  sale  agreements  and  other  similar
     agreements entered into with the approval of the Board of Directors,  which
     limitation or prohibition is applicable only to the assets that are subject
     of such agreements; or

          (j)  restrictions  on cash or other  deposits or net worth  imposed by
     customers or suppliers under contracts  entered into in the ordinary course
     of business.



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     (i)  Section  3.7 is amended by (i)  deleting  the word "and" at the end of
clause (p) and (ii) inserting the following immediately before the final proviso
in such Section:

          (r) Liens not in respect of Indebtedness consisting of the interest of
     the lessor under any lease entered into in the ordinary  course of business
     and not  otherwise  prohibited  by this  Indenture;  and Liens on shares of
     Capital  Stock of a  Subsidiary  that does not own any  significant  assets
     other than a lessee's  interest in a Facility or on the Capital  Stock of a
     Subsidiary whose only significant  asset is its direct or indirect interest
     in such  lessee  Subsidiary;  and (s)  Liens  (i) on  cash  and  short-term
     investments of Restricted  Subsidiaries to secure  obligations with respect
     to (A)  contracts  for  commercial  and trading  activities in the ordinary
     course of business  and  contracts  (including  physical  delivery,  option
     (whether cash or financial),  exchange, swap and futures contracts) for the
     purchase,   transmission,   distribution,  sale,  lease  or  hedge  of  any
     energy-related  commodity or service or (B) interest rate, commodity price,
     or currency rate management  contracts or derivatives and (ii)  encumbering
     assets of a  Restricted  Subsidiary,  other  than (1)  Material  Designated
     Assets or (2) accounts or  receivables,  which Liens arise out of contracts
     or agreements  relating to the generation,  distribution or transmission or
     sale of energy and/or fuel;  provided that all such agreements or contracts
     are entered into in the ordinary course of business;

     (j) Section  3.17 is deleted in its entirety  and the term  "[Deleted]"  is
inserted in lieu thereof.

                                   ARTICLE III
                                  MISCELLANEOUS

     Section 3.1 Notification of Holders.

     The Company shall notify the Holders in accordance  with Section 8.2 of the
Indenture of the execution of this Supplemental Indenture.

     Section 3.2 Ratification of Indenture.

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

     Section 3.3 Governing Law.

     This Supplemental  Indenture shall be deemed to be a contact made under the
laws of the  State of New  York,  and for all  purposes  shall be  construed  in
accordance with the laws of said State.



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     Section 3.4 Separability.

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

     Section 3.5 Counterparts.

     This  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.

     Section 3.6 Effectiveness.

     This Supplemental Indenture shall be effective and binding when executed by
the Company and the Trustee.

     Section 3.7 Trustee not Responsible for Recitals.

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

     Section 3.8 Performance by Trustee.

     The  Trustee,  for  itself  and its  successor  accepts  the  Trust  of the
Indenture as amended by this  Supplemental  Indenture  and agrees to perform the
same,  but only  upon the  terms  and  conditions  set  forth in the  Indenture,
including  the terms and  provisions  defining and limiting  the  liability  and
responsibility of the Trustee.



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

                                        CALPINE CORPORATION


                                        By:   /s/ ANN B. CURTIS
                                            ------------------------------------
                                            Name: Ann B. Curtis
                                            Title: Executive Vice President


                                        U.S. BANK NATIONAL ASSOCIATION,
                                         as Trustee


                                        By:  /s/ ARTHUR L. BLAKESLEE
                                            ------------------------------------
                                            Name: Arthur L. Blakeslee
                                            Title: Vice President



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