Chesapeake Energy (CHK)

Executive Summary, page 32

Securities and Exchange Commission

June 13, 2008

Page 5 of 14

Response: We believe the 2007 Form 10-K adequately discusses each of the matters raised by the Staff with regard to the reserve replacement ratios presented.

A discussion of the uncertainties inherent in estimates of proved reserves appears on page 9 in the penultimate paragraph of “Oil and Natural Gas Reserves” in Item 1 and is reproduced below. While the discussion of uncertainties applies generally to reported proved reserves, the last sentence cautions the reader that these uncertainties are particularly true for proved undeveloped reserves. We also refer you to a risk factor on proved reserve estimates, “The actual quantities and present value of our proved reserves may prove to be lower than we have estimated,” which appears on pages 22-23.

There are numerous uncertainties inherent in estimating quantities of proved reserves and in projecting future rates of production and timing of development expenditures, including many factors beyond Chesapeake’s control. The reserve data represent only estimates. Reserve engineering is a subjective process of estimating underground accumulations of oil and natural gas that cannot be measured in an exact way, and the accuracy of any reserve estimate is a function of the quality of available data and of engineering and geological interpretation and judgment. As a result, estimates made by different engineers often vary. In addition, results of drilling, testing and production subsequent to the date of an estimate may justify revision of such estimates, and such revisions may be material. Accordingly, reserve estimates are often different from the actual quantities of oil and natural gas that are ultimately recovered. Furthermore, the estimated future net revenue from proved reserves and the associated present value are based upon certain assumptions, including prices, future production levels and costs that may not prove correct. Future prices and costs may be materially higher or lower than the prices and costs as of the date of any estimate. A change in price of $0.10 per mcf for natural gas and $1.00 per barrel for oil would result in a change in the December 31, 2007 present value of estimated future net revenue of our proved reserves of approximately $390 million and $56 million, respectively. The estimated future net revenue used in this analysis does not include the effects of future income taxes or hedging. The foregoing uncertainties are particularly true as to proved undeveloped reserves, which are inherently less certain than proved developed reserves and which comprise a significant portion of our proved reserves.

On page 33, at the end of the fifth paragraph under “Executive Summary,” we provide the following information about the time horizon of when the 2007 reserve additions are expected to be produced:

Securities and Exchange Commission

June 13, 2008

Page 6 of 14

Our percentage of proved undeveloped reserve additions to total proved reserve additions was approximately 29% in 2007, 38% in 2006 and 36% in 2005. Based on our current drilling schedule and budget, we expect that virtually all of the proved undeveloped reserves added in 2007 will begin producing within the next three to five years. Generally, proved developed reserves are producing at the time they are added or will begin producing within one year.

Please refer to the defined term “reserve replacement” on page 19 for the following description of how management uses this measure and its limitations:

Management uses the reserve replacement ratio as an indicator of the company’s ability to replenish annual production volumes and grow its reserves, thereby providing some information on the sources of future production. It should be noted that the reserve replacement ratio is a statistical indicator that has limitations. As an annual measure, the ratio is limited because it typically varies widely based on the extent and timing of new discoveries and property acquisitions. Its predictive and comparative value is also limited for the same reasons. In addition, since the ratio does not imbed the cost or timing of future production of new reserves, it cannot be used as a measure of value creation.