Exhibit (a)(1)(C)

NOTICE OF GUARANTEED DELIVERY

To Tender Shares of Common Stock

of

Bronco Drilling Company, Inc.

Pursuant to the Offer to Purchase

dated April 26, 2011

by

Nomac Acquisition, Inc.

an indirect wholly owned subsidiary of

Chesapeake Energy Corporation

This form, or a substantially equivalent form, must be used to accept the offer (as defined below) if the certificates for shares of common stock, par value $0.01 per share, of Bronco Drilling Company, Inc. and any other documents required by the Letter of Transmittal cannot be delivered to the Depositary by Monday, May 23, 2011 (or if the offer is extended to a later date, such later date). Such form may be delivered by facsimile transmission or mail to the Depositary. See Section 3 of the Offer to Purchase.

The Depositary for the Offer to Purchase is:

By Mail:	By Facsimile Transmission:	By Overnight Courier:
Computershare c/o Voluntary Corporate Actions P.O. Box 43011 Providence, RI 02940-3011	For Eligible Institutions Only: (617) 360-6810 For Confirmation Only Telephone: (781) 575-2332	Computershare c/o Voluntary Corporate Actions 250 Royall Street/Suite V Canton, MA 02021

DELIVERY OF THIS NOTICE OF GUARANTEED DELIVERY TO AN ADDRESS OR FACSIMILE OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY.

This Notice of Guaranteed Delivery is not to be used to guarantee signatures. If a signature on a Letter of Transmittal is required to be guaranteed by an Eligible Institution under the instructions thereto, such signature guarantee must appear in the applicable space provided in the signature box on the Letter of Transmittal. Do not send share certificates with this notice. Share certificates should be sent with your Letter of Transmittal.

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Ladies and Gentlemen:

The undersigned hereby tenders to Nomac Acquisition, Inc., a Delaware corporation and an indirect wholly owned subsidiary of Chesapeake Energy Corporation, an Oklahoma corporation, upon the terms and subject to the conditions set forth in the Offer to Purchase dated April 26, 2011 and the related Letter of Transmittal (which, together with any amendments or supplements thereto, collectively constitute the “offer”), receipt of which is hereby acknowledged,                         shares of common stock, par value $0.01 per share (the “Bronco shares”), of Bronco Drilling Company, Inc., a Delaware corporation, pursuant to the guaranteed delivery procedure set forth in Section 3 of the Offer to Purchase.

Certified Numbers (if available)

If delivery will be by book-entry transfer:

Name of Tendering Institution

Account Number

SIGN HERE

Signature(s)

(Name(s)) (Please Print)

(Addresses)

(Zip Code)

(Area Code and Telephone Number)

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GUARANTEE

(Not to be used for signature guarantee)

The undersigned, a firm which is a bank, broker, dealer, credit union, savings association or other entity which is a member in good standing of a recognized Medallion Program approved by The Securities Transfer Association Inc., including the Securities Transfer Agents Medallion Program (STAMP), the Stock Exchange Medallion Program (SEMP) and the New York Stock Exchange Inc. Medallion Signature Program (MSP) or any other “Eligible Guarantor Institution” (as such term is defined in Rule 17Ad-15 under the Securities Exchange Act of 1934, as amended), guarantees (i) that the above named person(s) “own(s)” the Bronco shares tendered hereby within the meaning of Rule 14e-4 under the Securities Exchange Act of 1934, (ii) that such tender of Bronco shares complies with Rule 14e-4 and (iii) to deliver to the Depositary the Bronco shares tendered hereby, together with a properly completed and duly executed Letter(s) of Transmittal and certificates for the Bronco shares to be tendered or an Agent’s Message (as defined in the Offer to Purchase) in the case of a book-entry delivery, and any other required documents, all within three NASDAQ trading days of the date hereof.

(Name of Firm)

(Address)

(Zip Code)

(Authorized Signature)

(Name and Title)

(Area Code and Telephone Number)

Dated:                     , 20    .

DO NOT SEND CERTIFICATES FOR SHARES WITH THIS NOTICE.

CERTIFICATES FOR SHARES SHOULD BE SENT WITH YOUR LETTER OF TRANSMITTAL.

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