SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 11-K

                 ANNUAL REPORT PURSUANT TO SECTION 15 (D) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

(Mark One)
[  ]  ANNUAL REPORT PURSUANT TO SECTION 15 (d) OF THE SECURITIES EXCHANGE ACT OF
        1934
        (FEE REQUIRED)

        For the fiscal year ended December 31, 2003

                                       Or

[X]   TRANSITION  REPORT PURSUANT TO SECTON 15 (D) OF THE SECURITIES  EXCHANGE
        ACT OF 1934 (No Fee Required)

        For the transition period from 7/1/03 to 12/31/03
                                       ------    --------

        Commission File No. 1-13726

        A. Full title of the plan and the address of the plan, if different from
that of the issuer named below:

                           NOMAC DRILLING 401 (K) PLAN
                            6100 NORTH WESTERN AVENUE
                             OKLAHOMA CITY, OK 73118

        B. Name of issuer of the  securities  held pursuant to  the plan and the
address of its principal executive office:

                           NOMAC DRILLING CORPORATION
                            6100 NORTH WESTERN AVENUE
                             OKLAHOMA CITY, OK 73118





NOMAC DRILLING CORPORATION
401(K) PLAN
FINANCIAL STATEMENTS AND SUPPLEMENTAL SCHEDULES
December 31, 2003




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NOMAC DRILLING CORPORATION
401(K) PLAN
CONTENTS
DECEMBER 31, 2003
- -------------------------------------------------------------------------------


                                                                           PAGE
FINANCIAL STATEMENTS  (UNAUDITED)

Statements of Net Assets Available for Benefits...............................1

Statements of Changes in Net Assets Available for Benefits....................2

Notes to Financial Statements.................................................3

SUPPLEMENTAL SCHEDULES

Schedule of Assets (Held at End of Year)......................................9

Schedule of Reportable Transactions..........................................10


                                       3




NOMAC DRILLING CORPORATION
401(K) PLAN
STATEMENT OF NET ASSETS AVAILABLE FOR BENEFITS (UNAUDITED)
DECEMBER 31, 2003
- -------------------------------------------------------------------------------





                                                                       2003
                                                                       ----

ASSETS
Investments.................................................     $     276,145
Receivables
     Dividends..............................................               424
                                                                 --------------
             Total assets...................................           276,569
                                                                 --------------

LIABILITIES
Accrued liabilities.........................................             7,823
                                                                 --------------
             Net assets available for benefits..............     $     268,746
                                                                 =============









   The accompanying notes are an integral part of these financial statements.

                                       4




NOMAC DRILLING CORPORATION
401(K) PLAN
STATEMENT OF CHANGES IN NET ASSETS  AVAILABLE FOR BENEFITS  (UNAUDITED)  FOR THE
PERIOD JULY 1, 2003 (DATE OF INCEPTION) TO DECEMBER 31, 2003
- -------------------------------------------------------------------------------



                                                                       2003
                                                                       ----

ADDITIONS TO NET ASSETS ATTRIBUTED TO
Investment income
   Interest and dividends...................................     $        1,944
   Net appreciation in fair value of investments............             35,679
                                                                 --------------
             Total investment income........................             37,623
                                                                 --------------

Contributions
   Employer.................................................            106,984
   Participants.............................................            132,956
                                                                 --------------
              Total contributions...........................            239,940
                                                                 --------------
              Total additions...............................            277,563
                                                                 --------------

DEDUCTIONS FROM NET ASSETS ATTRIBUTED TO
Benefits paid to participants...............................                986
   Administrative expenses..................................              7,831
                                                                 --------------
             Total deductions...............................              8,817
                                                                 --------------
             Net increase...................................            268,746
                                                                 --------------

NET ASSETS AVAILABLE FOR BENEFITS
Beginning of year...........................................                  -
End of year.................................................     $      268,746
                                                                 ==============




   The accompanying notes are an integral part of these financial statements.

                                       5



NOMAC DRILLING CORPORATION
401(K) PLAN
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
DECEMBER 31, 2003
- -------------------------------------------------------------------------------



1.       DESCRIPTION OF THE PLAN

         The following is a brief summary of the various provisions of the NOMAC
         Drilling  Corporation  401(K) Plan (the  "Plan").  Participants  should
         refer to the Plan  agreement for a complete  description  of the Plan's
         provisions.

         The financial  statements are prepared in accordance  with the Employee
         Retirement  Income Security Act of 1974  ("ERISA").  In accordance with
         ERISA, such financial statements for 2003 are unaudited.

         GENERAL
         The Plan is a defined  contribution  plan that covers all  employees of
         NOMAC Drilling Corporation (the "Company").

         CONTRIBUTIONS
         Each  year,  participants  may  contribute  up to 15 percent of pre-tax
         annual  compensation,  as  defined by the Plan.  Participants  may also
         contribute  amounts  representing  rollover  distributions  from  other
         qualified  plans.  The  Company  makes  matching  contributions  of 100
         percent of the first 6 percent  of  participant  contributions.  Profit
         sharing  contributions  may be made at the  discretion of the Company's
         board of directors.  No discretionary profit sharing contributions were
         made in 2003. Contributions are subject to certain limitations.

         The  Company's  matching  contribution  is used to  purchase  shares of
         Chesapeake Energy  Corporation Common Stock (the "Common Stock") on the
         open market.  Participants may also elect to direct all or a portion of
         their  contributions  into  the  Common  Stock.  Participants  may  not
         transfer or liquidate  their  investment  in Common Stock  arising from
         employer  contributions  and  earnings  thereon  until  they  elect  to
         withdraw  from  the  Plan  due to  separation  of  service  or elect an
         in-service distribution upon attainment of age 59 1/2 .

         PARTICIPANT ACCOUNTS
         Each   participant's   account  is  credited  with  the   participant's
         contribution  and  allocations of the Company's  contribution  and Plan
         earnings.  Allocations  are based on  participant  earnings  or account
         balances, as defined. The benefit to which a participant is entitled is
         the benefit that can be provided from the participant's  vested account
         balance.

         VESTING
         Participants are immediately vested in their  contributions plus actual
         earnings thereon.  Vesting in the Company's matching and profit sharing
         contributions  plus  actual  earnings  thereon  is  based  on  years of
         credited  service  or  participant's  age.  A  participant  will be 100
         percent vested after five years of credited service.




                                       6




NOMAC DRILLING CORPORATION
401(K) PLAN
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
DECEMBER 31, 2003
- -------------------------------------------------------------------------------

         PARTICIPANT NOTES RECEIVABLE
         Participants may borrow from their accounts a minimum of $1,000 up to a
         maximum  equal to the lesser of  $50,000 or 50 percent of their  vested
         account  balance.  Loan terms range from one to five years or up to ten
         years  for  the  purchase  of  a  primary  residence.   The  loans  are
         collateralized  by the  balance in the  participant's  account and bear
         interest at the Prime  Interest  Rate.  Principal  and interest is paid
         ratably  through  semi-monthly  payroll  deductions.  Interest rates on
         loans outstanding at December 31, 2003 were 10 percent.

         PAYMENT OF BENEFITS
         Upon termination of service due to death, retirement or separation from
         service,  a participant  may elect to receive either a lump-sum  amount
         equal to the value of the  participant's  vested interest in his or her
         account, annual installments,  or have the value rolled over to another
         qualified plan or IRA.

         AMOUNTS FORFEITED
         Forfeited  nonvested  amounts  are  first  used  to pay  administrative
         expenses  of the Plan or to restore  unvested  amounts  to  re-employed
         participants.  Any  remaining  forfeitures  are used to reduce  Company
         contributions into the Plan.  Forfeited nonvested accounts totaled $736
         at December 31, 2003.  During 2003 forfeited  nonvested  accounts of $0
         were used to pay  administrative  expenses of the plan and $0 were used
         to reduce employer matching contributions.


2.       SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

         BASIS OF ACCOUNTING
         The  financial  statements  of the Plan are prepared  under the accrual
         method of accounting.

         USE OF ESTIMATES
         The  preparation of financial  statements in conformity  with generally
         accepted  accounting  principles  requires management to make estimates
         and  assumptions  that  affect  the  reported  amounts  of  net  assets
         available for benefits at the date of the financial  statements and the
         changes in net  assets  available  for  benefits  during the  reporting
         period. Actual results could differ from those estimates.

         INVESTMENT VALUATION AND INCOME RECOGNITION
         The Plan's investments are stated at fair value. Shares of mutual funds
         are  valued at quoted  market  prices on the last  business  day of the
         year.  Chesapeake  Energy  Corporation  common  stock is  valued at the
         closing market price on the last business day of the year, according to
         the New York Stock Exchange. Participant loans receivable are valued at
         outstanding principal balance, which approximates fair value.

         Purchases and sales of securities  are recorded on a trade-date  basis.
         Investment  income is  recorded  on the accrual  basis.  Dividends  are
         recorded on the ex-dividend date.



                                       7




NOMAC DRILLING CORPORATION
401(K) PLAN
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
DECEMBER 31, 2003
- -------------------------------------------------------------------------------


         The Plan presents,  in the statement of changes in net assets available
         for benefits, the net appreciation  (depreciation) in the fair value of
         investments  which  consists  of the  realized  gains or losses and the
         unrealized appreciation (depreciation) on those investments.

         PAYMENT OF BENEFITS
         Benefits are recorded when paid.

         RISKS AND UNCERTAINTIES
         Investment  securities are exposed to various  risks,  such as interest
         rate, market, and credit risk. Due to the level of risk associated with
         certain investment securities,  it is at least reasonably possible that
         changes in value of investment  securities  will occur in the near term
         and that such changes could  materially  affect  participants'  account
         balances  and the  amounts  reported  in the  statement  of net  assets
         available  for  benefits  and the  statement  of  changes in net assets
         available for benefits.

3.       INVESTMENTS
         The following  presents  investments  that  represented five percent or
         more of the Plan's net assets:

                                                                      2003
                                                                      ----

         Chesapeake Energy Corporation Common Stock.........     $     164,513*
         Fidelity Freedom 2020..............................             26,365
         Fidelity Freedom 2030..............................             15,173

         * Balance includes nonparticipant-directed investments.

         The  Plan's  investments  (including  gains and  losses on  investments
         bought  and  sold,  as  well  as  held  during  the  year)  appreciated
         (depreciated) in value as follows:

                                                                      2003
                                                                      ----

         Mutual funds.......................................     $        5,206
         Common stocks......................................             30,473
                                                                 --------------
                                                                 $       35,679




                                       8




NOMAC DRILLING CORPORATION
401(K) PLAN
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
DECEMBER 31, 2003
- -------------------------------------------------------------------------------

4.       NONPARTICIPANT-DIRECTED INVESTMENTS

         Investment in the Chesapeake Energy  Corporation  common stock includes
         balances  arising  from   nonparticipant-directed   employer   matching
         contributions,  as  well  as  participant-directed   contributions  and
         transfers  from other  investment  options.  Information  about the net
         assets  and the  significant  components  of the  changes in net assets
         relating to  investments in the Chesapeake  Energy  Corporation  common
         stock is as follows:

                                                                       2003
                                                                       ----

         NET ASSETS
         Chesapeake Energy Corporation Common Stock.........     $      164,513
                                                                 ==============

         CHANGES IN NET ASSETS
         Contributions......................................     $      131,606
         Dividend income....................................                213
         Net appreciation...................................             30,472
         Benefits paid to participants......................              (357)
         Transfers from (to) other investments options, net.              2,579
                                                                 --------------
                                                                 $      164,513


5.       PARTY-IN-INTEREST TRANSACTIONS

         Certain Plan  investments are shares of Chesapeake  Energy  Corporation
         common stock. These transactions  represent investments in the Company,
         and, therefore,  qualify as  party-in-interest  transactions.  Further,
         certain Plan investments are shares of mutual funds managed by Fidelity
         Investments.  Fidelity  Management  Trust  Company  is the  trustee  as
         defined  by the Plan,  and,  therefore,  transactions  in mutual  funds
         managed  by   Fidelity   Investments   qualify   as   party-in-interest
         transactions.


6.       TAX STATUS

         The Plan  received an Internal  Revenue  Service  opinion  letter dated
         October 9, 2003 with respect to the prototype adopted by the Plan which
         indicates  that the Plan as  designed  at the date of the  letter is in
         compliance  with the applicable  requirements  of the Internal  Revenue
         Code (the  "IRC").  The Plan  Administrator  and the Plan's tax counsel
         believe the Plan is currently designed and being operated in compliance
         with the applicable  requirements of the IRC.  Therefore,  no provision
         for income taxes has been included in the Plan's financial statements.

                                       9



NOMAC DRILLING CORPORATION
401(K) PLAN
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
DECEMBER 31, 2003
- -------------------------------------------------------------------------------

7.       PLAN TERMINATION

         Although the Company has not expressed any intent to do so, the Company
         reserves  the right to  change,  amend or  discontinue  the Plan at any
         time,   subject  to  the   provisions   of  ERISA.   In  the  event  of
         discontinuance of the Plan, participants will become 100 percent vested
         in their accounts.


8.       CONCENTRATION OF INVESTMENTS

         As of December 31, 2003 net assets available for benefits in the amount
         of $164,513 and $109,289  were  invested in  Chesapeake  Energy  Common
         Stock and mutual funds managed by Fidelity Investments, respectively.


9.       RECONCILIATION OF FINANCIAL STATEMENTS TO FORM 5500

         The following is a reconciliation  of net assets available for benefits
         as of December 31, 2003,  as  reflected in the  accompanying  financial
         statements, to the Form 5500:

                                                                       2003
                                                                       ----

         Net assets available for benefits
           per the financial statements.....................            268,746
         Add: Accrued administrative expenses...............              7,823
         Less: Accrued dividend income......................               (424)
                                                                 $      276,145
                                                                 ==============

         The following is a reconciliation  of  administrative  expenses for the
         years  ended  December  31,  2003,  as  reflected  in the  accompanying
         financial statements, to the Form 5500:

                                                                      2003
                                                                      ----

         Administrative expenses per the financial statements... $        7,831
         Add: Previous year accrued administrative expenses.....             --
         Less: Current year accrued administrative expenses.....         (7,823)
         Administrative expenses per the Form 5500               $            8
                                                                 ==============




         Administrative expenses are recorded on the Form 5500 when paid.




                                       10



NOMAC DRILLING CORPORATION
401(K) PLAN
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
DECEMBER 31, 2003
- -------------------------------------------------------------------------------


         The following is a  reconciliation  of interest and dividend income for
         the years ended  December  31, 2003,  as reflected in the  accompanying
         financial statements, to the Form 5500:

                                                                      2003
                                                                      ----

         Interest and dividends per the financial statements.....$        1,944
         Add: Previous year accrued interest and dividend income.            --
         Less: Current year accrued interest and dividend income.          (424)
                                                                 --------------
         Interest and dividends per the Form 5500                $        1,520
                                                                 ==============




         Dividend income was recorded on the Form 5500 when paid.




                                       11




NOMAC DRILLING CORPORATION
401(K) PLAN
SCHEDULE OF ASSETS (HELD AT END OF YEAR)
DECEMBER 31, 2003
                                                                     SCHEDULE 1
- -------------------------------------------------------------------------------




                                                   DESCRIPTION OF INVESTMENT
                                                    INCLUDING MATURITY DATE
        IDENTITY OF ISSUE, BORROWER,             RATE OF INTEREST, COLLATERAL,                            CURRENT
           LESSOR, OR SIMILAR PARTY                  PAR, OR MATURITY VALUE         COST                   VALUE
                                                                                              
*Chesapeake Energy/Nomac Corporation......                Common Stock                $134,972         $    164,513
*Fidelity Contra fund.....................                Mutual Funds                    **                    946
*Fidelity Investment Grade Bonds..........                Mutual Funds                    **                  7,123
*Fidelity Independence Fund...............                Mutual Funds                    **                  4,247
*Fidelity Low Prices Stock Fund...........                Mutual Funds                    **                  1,472
*Fidelity Equity II Fund..................                Mutual Funds                    **                  2,252
*Fidelity Diversified International Fund..                Mutual Funds                    **                  4,815
*Fidelity Dividend Growth.................                Mutual Funds                    **                  3,648
*Fidelity Mid-Cap Stocks..................                Mutual Funds                    **                  5,408
*Fidelity Freedom Income..................                Mutual Funds                    **                  3,596
*Fidelity Freedom 2000....................                Mutual Funds                    **                  1,050
*Fidelity Freedom 2010....................                Mutual Funds                    **                 12,834
*Fidelity Freedom 2020....................                Mutual Funds                    **                 26,365
*Fidelity Freedom 2030....................                Mutual Funds                    **                 15,173
*Fidelity Freedom 2040....................                Mutual Funds                    **                 10,545
*Fidelity Retirement Money Market.........                Mutual Funds                    **                  4,234
*Spartan US Equity Index..................                Mutual Funds                    **                  5,581
*Participant Loans........................       Interest Rates Were 10 percent           **                  2,343
                                                                                                       ------------
                                                                                                       $    276,145
                                                                                                       ============

*   Identifies parties-in-interest.

** Identifies  participant-directed investment options for which presentation of
   cost in the Schedule of Assets (Held at End of Year) is not required.




                                       12





NOMAC DRILLING CORPORATION
401(K) PLAN
SCHEDULE OF REPORTABLE TRANSACTIONS
DECEMBER 31, 2003
                                                                     SCHEDULE 2
- -------------------------------------------------------------------------------






                                                                               TOTAL          TOTAL
                                                NUMBER OF      NUMBER OF      PURCHASE       SELLING       NET GAIN
             DESCRIPTION OF ASSET               PURCHASES        SALES         PRICE          PRICE         (LOSS)
                                                                                                 
*Chesapeake Energy Corporation
  Stock Purchases..........................        18              --          $ 106,984         --             --


* Identifies parties-in-interest.



                                       13







                                   SIGNATURES

      Pursuant to the  requirements of the Securities  Exchange Act of 1934, the
trustee has duly  caused  this  annual  report to be signed on its behalf by the
undersigned hereunto duly authorized.


                                        NOMAC DRILLING CORPORATION
                                           401(K) Plan



                                        By:    /S/ MARY WHITSON
                                           -------------------------------------
                                               Mary Whitson, Plan Administrator
Date:  August 17, 2004

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