EXHIBIT 4.1
                                                                     ----------


                          TENTH SUPPLEMENTAL INDENTURE

         TENTH SUPPLEMENTAL INDENTURE (this "Supplemental Indenture"),  dated as
of December 21, 2004 is by and among Chesapeake Energy Corporation,  an Oklahoma
corporation  (the  "Company"),  the  Subsidiary  Guarantors  (as  defined in the
Indenture  referred  to  herein),  The Bank of New  York as  trustee  under  the
Indenture  referred to below (the "Trustee").  All capitalized terms not defined
herein shall have the meaning ascribed to them in the Indenture.

         WHEREAS,  the Company has  heretofore  executed  and  delivered  to the
Trustee an indenture (the  "Indenture"),  dated as of November 5, 2001, and such
Indenture was supplemented and amended by (i) the First  Supplemental  Indenture
dated December 17, 2001, (ii) the Second  Supplemental  Indenture dated June 28,
2002, (iii) the Third Supplemental Indenture dated July 8, 2002, (iv) the Fourth
Supplemental  Indenture  dated  February  14, 2003,  (v) the Fifth  Supplemental
Indenture dated May 1, 2003, (vi) the Sixth Supplemental  Indenture dated August
15, 2003, (vii) the Seventh  Supplemental  Indenture dated March 5, 2004, (viii)
the Eighth  Supplemental  Indenture  dated August 30,  2004,  and (ix) the Ninth
Supplemental Indenture dated September 27, 2004.

         WHEREAS, on November 5, 2001, the Company issued $250,000,000 aggregate
principal amount of its 8.375% Senior Notes due 2008;

         WHEREAS,  Section  9.01(3) of the Indenture  provides that the Company,
the Subsidiary  Guarantors and the Trustee may amend or supplement the Indenture
without  notice to or  consent  of any  Holder to  reflect  the  release  of any
Subsidiary Guarantor as provided for in the Indenture;

         WHEREAS,  the  Company  has taken all  actions  required  to effect the
release,  pursuant to Sections 10.02 and 10.04 of the  Indenture,  of Chesapeake
Panhandle Limited Partnership ("CPLP") as Subsidiary Guarantor;

         WHEREAS,  Section 9.02 of the Indenture provides that, with the consent
of the Holders of a majority  in  aggregate  principal  amount of the Notes then
outstanding  (including  consents obtained in connection with a tender offer for
the  Notes),  the  Company,  when  authorized  by a  resolution  of its Board of
Directors,  and the Trustee may enter into a  supplemental  to the Indenture for
the purpose of amending or  supplementing  any provisions of the Indenture (with
certain exceptions not relevant to this Supplemental Indenture);

         WHEREAS,  the Company  and the  Subsidiary  Guarantors  desire and have
requested  the  Trustee  to join with them in  entering  into this  Supplemental
Indenture for the purpose of amending the Indenture to remove certain  covenants
and events of default as permitted by Section 9.02 of the Indenture;

         WHEREAS,  the  Company  has  solicited  consents  to this  Supplemental
Indenture upon the terms and subject to the conditions set forth in its Offer to
Purchase  and Consent  Solicitation  Statement  dated  November 12, 2003 and the
related Letter of Transmittal and Consent (which together constitute the "Tender
Offer");

         WHEREAS,  the  Company (1) has  received  the consent of the Holders of
more than 50% in aggregate  principal  amount of the outstanding  Notes, (2) has
delivered  to the Trustee an Opinion of Counsel  relating  to this  Supplemental
Indenture as contemplated by Section 9.06 of the Indenture and (3) has satisfied
all other  conditions  required  under  Article 9 of the Indenture to enable the
Company and the Trustee to enter into this Supplemental Indenture.

         NOW,  THEREFORE,  in  consideration of the foregoing and for other good
and  valuable  consideration,  the receipt and  sufficiency  of which are hereby
acknowledged,  the Company,  the Subsidiary  Guarantors and the Trustee mutually
covenant and agree for the equal and ratable benefit of the Holders as follows:




                                    ARTICLE I
                              SUBSIDIARY GUARANTOR

         1.1 MERGER OF SUBSIDIARY.  As a result of the merger of CPLP,  with and
into Chesapeake  Exploration Limited Partnership  ("CELP"),  an Oklahoma limited
partnership,  which  constitutes  a merger  with a  Subsidiary  Guarantor  under
Section 10.02(a) of the Indenture,  CPLP shall for all purposes be released as a
Subsidiary  Guarantor  from all of its Guarantee and related  obligations in the
Indenture,  pursuant  to Section  10.04 of the  Indenture  The  notation  on the
Securities relating to the Guarantee shall be deemed to exclude the name of GPLP
and the signature of an Officer of CPLP on its behalf.

         1.2 SURVIVING  ENTITY.  As the surviving entity in its merger with CPLP
and a Subsidiary Guarantor,  CELP hereby agrees to assume all of the obligations
of CPLP.

                                   ARTICLE II
                                   DEFINITIONS

         2.1  DELETION OF  DEFINITIONS  AND RELATED  REFERENCES.  Section 1.1 of
Article 1 of the  Indenture  is hereby  amended to delete in their  entirety all
terms and their  respective  definitions for which all references are eliminated
in the Indenture as a result of the  amendments  set forth in Article II of this
Supplemental Indenture.

                                   ARTICLE III
                             AMENDMENTS TO INDENTURE

         3.1  AMENDMENTS TO ARTICLES 4, 5 AND 6. The Indenture is hereby amended
by deleting the following  sections of the Indenture and all references  thereto
in  their  entirety:   Section  4.2  (SEC  REPORTS);   Section  4.3  (COMPLIANCE
CERTIFICATES);  Section 4.4  (MAINTENANCE  OF AN OFFICE OR AGENCY);  Section 4.5
(CORPORATE  EXISTENCE)  Section 4.6 (WAIVER OF STAY,  EXTENSION  OR USURY LAWS);
Section 4.7 (PAYMENT OF TAXES AND OTHER  CLAIMS);  Section 4.8  (MAINTENANCE  OF
PROPERTIES  AND  INSURANCE);  Section 4.9  (LIMITATION  ON LIENS);  Section 4.10
(Limitation  on  Restricted  Payments);  Section  4.11  (Limitation  on  Sale of
Assets); Section 4.12 (Limitation on Liens Securing Indebtedness);  Section 4.13
(LIMITATION ON SALE/LEASEBACK TRANSACTIONS); Section 4.14 (Limitation on Payment
Restrictions Affecting  Subsidiaries);  Section 4.15 (Limitation on Transactions
with  Affiliates);  Section 4.16 (Change of Control);  Section 5.1 (WHEN COMPANY
MAY MERGE,  ETC.) and each of subsections  (4), (5), (6), (8) and (9) of Section
6.1 (EVENTS OF DEFAULT).

                                   ARTICLE IV
                                  MISCELLANEOUS

         4.1 DEFINITIONS. Capitalized terms used herein without definition shall
have the meanings  assigned to them in the  Indenture.  For all purposes of this
Supplemental Indenture,  except as otherwise herein expressly provided or unless
the context otherwise  requires,  the words "herein,"  "hereof" and "hereby" and
other words of similar import used in this Supplemental  Indenture refer to this
Supplemental Indenture as a whole and not to any particular section hereof.

         4.2   RATIFICATION  OF  INDENTURE;   SUPPLEMENTAL   INDENTURE  PART  OF
INDENTURE.  Except as expressly amended hereby, the Indenture is in all respects
ratified and  confirmed and all the terms,  conditions  and  provisions  thereof
shall remain in full force and effect. This Supplemental  Indenture shall form a
part of the Indenture for all purposes,  and every Holder of Notes heretofore or
hereafter  authenticated and delivered under the Indenture shall be bound hereby
and all terms and  conditions  of both  shall be read  together  as though  they
constitute  a  single  instrument,  except  that  in the  case of  conflict  the
provisions of this Supplemental Indenture shall control.

         4.3  ENDORSEMENT AND CHANGE OF FORM OF NOTES.  Any Notes  authenticated
and  delivered  after the close of business  on the date that this  Supplemental
Indenture  becomes  operative in substitution for Notes then outstanding and all
Notes  presented  or  delivered  to the  Trustee on and after that date for such
purpose shall be stamped, imprinted or otherwise legended by the Trustee, with a
notation as follows:

                  "Effective  as  of  December  14,  2004  certain   restrictive
         covenants  of the  Company  and  certain  Events of  Default  have been
         eliminated or limited, as provided in the Tenth Supplemental Indenture,
         dated as of December 14,  2004.  Reference is hereby made to said Tenth
         Supplemental  Indenture,  copies of which are on file with the Trustee,
         for a description of the amendments made therein."



     4.4 GOVERNING  LAW. This  Supplemental  Indenture  shall be governed by and
construed in accordance with the laws of the State of New York.

     4.5 TRUSTEE MAKES NO REPRESENTATION. The Trustee makes no representation as
to the  validity or  sufficiency  of this  Supplemental  Indenture  or for or in
respect of the recitals  contained  herein,  all of which are made solely by the
Company and the Guarantors.

         4.6  COUNTERPARTS.  The  parties  may  sign any  number  of  copies  or
counterparts  of this  Supplemental  Indenture.  Each  signed  copy  shall be an
original, but all of them together represent the same agreement.

     4.7 EFFECT OF HEADINGS.  The Section  headings  herein are for  convenience
only and shall not affect the construction thereof.

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

                                    COMPANY:

                                    CHESAPEAKE ENERGY CORPORATION


                                    By:    /s/ Aubrey K. McClendon
                                           ------------------------------------
                                    Name:   Aubrey K. McClendon
                                    Title:  Chief Executive Officer


                                    SUBSIDIARY GUARANTORS:

                                    CHESAPEAKE BNR CORP.
                                    CHESAPEAKE ENERGY LOUISIANA CORPORATION
                                    CHESAPEAKE ENERGY MARKETING, INC.
                                    CHESAPEAKE OPERATING, INC.
                                    CHESAPEAKE PRH CORP.
                                    CHESAPEAKE SOUTH TEXAS CORP.
                                    NOMAC DRILLING CORPORATION
                                    OXLEY PETROLEUM CO.
                                    CARMEN ACQUISITION, L.L.C.
                                    CHESAPEAKE ACQUISITION, L.L.C.
                                    CHESAPEAKE ENO ACQUISITION, L.L.C.
                                    CHESAPEAKE EP, L.L.C.
                                    CHESAPEAKE FOCUS, L.L.C.
                                    CHESAPEAKE KNAN ACQUISITION, L.L.C.
                                    CHESAPEAKE MOUNTAIN FRONT, L.L.C.
                                    CHESAPEAKE ORC, L.L.C.
                                    CHESAPEAKE PERMIAN ACQUISITION, L.L.C.
                                    CHESAPEAKE ROYALTY, L.L.C.
                                    GOTHIC PRODUCTION, L.L.C.
                                    JOHN C. OXLEY, L.L.C.
                                    MAYFIELD PROCESSING, LLC
                                    MC MINERAL COMPANY, L.L.C.
                                    SAP ACQUISITION, L.L.C.


                                    By:    /s/ Aubrey K. McClendon
                                           ------------------------------------
                                    Name:   Aubrey K. McClendon
                                    Title:  Chief Executive Officer


                                    CHESAPEAKE EXPLORATION LIMITED PARTNERSHIP
                                    CHESAPEAKE LNG, L.P.
                                    CHESAPEAKE LOUISIANA, L.P.
                                    CHESAPEAKE NFW, L.P.
                                    CHESAPEAKE PERMIAN, L.P.
                                    CHESAPEAKE SIGMA, L.P.
                                    CHESAPEAKE ZAPATA, L.P.
                                    CHESAPEAKE-STAGHORN ACQUISITION L.P.

                                    By:  Chesapeake Operating, Inc.,
                                         as general partner of each
                                         representative entity


                                    By:    /s/ Aubrey K. McClendon
                                           ------------------------------------
                                    Name:   Aubrey K. McClendon
                                    Title:  Chief Executive Officer

                                    MIDCON COMPRESSION, L.P.

                                    By:  Chesapeake Energy Marketing, Inc.,
                                         as general partner

                                    By:    /s/ Aubrey K. McClendon
                                           ------------------------------------
                                    Name:   Aubrey K. McClendon
                                    Title:  Chief Executive Officer



                                    TRUSTEE:

                                    THE BANK OF NEW YORK


                                    By:    /s/ Steven D. Torgeson
                                           ------------------------------------
                                    Name:   Steven D. Torgeson
                                    Title:  Vice President