4 1 efh02052003.txt FORM 4 EFH02-05-03 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 4 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. 1. Name and Address of Reporting Person(s) HEIZER EDGAR F. 261 BLUFF'S EDGE DRIVE LAKE FOREST, IL 60045 2. Issuer Name and Ticker or Trading Symbol Chesapeake Energy Corporation (CHK) 3. I.R.S. Identification Number of Reporting Person, if an entity (Voluntary) 4. Statement for Month/Year 02/03 5. If Amendment, Date of Original (Month/Year) 6. Relationship of Reporting Person(s) to Issuer (Check all applicable) [X] Director [ ] 10% Owner [ ] Officer (give title below) [ ] Other (specify below) Director 7. Individual or Joint/Group Filing (Check Applicable Line) [X] Form filed by One Reporting Person [ ] Form filed by More than One Reporting Person

Table I Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned ------------------------------------------------------------------------------------------------------------------------------------ 1)Title of Security 2)Trans- 3.Trans- 4.Securities Acquired(A) 5)Amount of 6) 7)Nature of action action or Disposed of (D) Securities Indirect Date Code A Beneficially D Beneficial (Month/ or Owned at or Ownership Day/Year) Code V Amount D Price End of Month I ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 02/05/03 X 47,250 A $1.3334 756,900 D Direct Table II (PART 1) Derivative Securities Acquired, Disposed of, or Beneficially Owned (Columns 1 through 6) ------------------------------------------------------------------------------------------------------------------------------------ 1)Title of Derivative 2)Conversion 3)Trans- 4)Trans- 5)Number of Derivative 6)Date Exercisable and Security or Exercise action action Securities Acquired (A) Expiration Date Price of Date Code or Disposed of (D) Derivative Security Code V A D Exercisable Expiration ------------------------------------------------------------------------------------------------------------------------------------ Non-Qualified Stock Option $81.~~0500~~3334 ~~01/~~02/05/03 AX 1047,~~000~~250 ~~01/~~02/1311/03 (right to buy) Table II (PART 2) Derivative Securities Acquired, Disposed of, or Beneficially Owned (Columns 1,3 and 7 through 11) ------------------------------------------------------------------------------------------------------------------------------------ 1)Title of Derivative 3)Trans- 7)Title and Amount 8)Price 9)Number of 10) 11)Nature of Security action of Underlying of Deri- Derivative Indirect Date Securities vative Securities D Beneficial Amount or Security Beneficially or Ownership Number of Owned at I - Title Shares End of Month ------------------------------------------------------------------------------------------------------------------------------------ Non-Qualified Stock Option ~~01/~~02/05/03 Common Stock 1047,~~000~~250 ~~10,000~~0 D Direct (right to buy) Explanation of Responses:

SIGNATURE OF REPORTING PERSON /S/ By: Jennifer M. Grigsby For: Edgar F. Heizer, Jr. DATE 02/06/03

Filing Compare · HEIZER EDGAR JR