Harvest Oil & Gas (HRST) S-1 IPO registration

Exhibit 23.1

Cawley, Gillespie & Associates, Inc.

PETROLEUM CONSULTANTS

9601 AMBERGLEN BLVD., SUITE 117
AUSTIN, TEXAS 78729-1106
512-249-7000
FAX 512-233-2618
306 WEST SEVENTH STREET, SUITE 302
FORT WORTH, TEXAS 76102-4987
817-336-2461
FAX 817-877-3728
www.cgaus.com
1000 LOUISIANA STREET, SUITE 625
HOUSTON, TEXAS 77002-5008
713-651-9944
FAX 713-651-9980

May 10, 2006

Mr. Michael E. Mercer
EV Energy Partners, L.P.
1001 Fannin St, Suite 900
Houston, TX 77002

Re:    Release to reference our name

Dear Mr. Mercer:

     This letter is written at the request of EV Energy Partners, L.P., a Delaware limited partnership (the “Company”), and is being delivered to you pursuant to that certain Form S-1 Registration Statement (the “Prospectus”) in connection with an initial public offering (the “Offering”) of shares of common stock of the Company. We hereby consent to the use of our name in the Prospectus and to the incorporation by reference of our estimates of proved reserves and future net cash flows for the year ended December 31, 2005.

Very truly yours, Cawley, Gillespie & Associates, Inc.
By:	/s/ W. Todd Brooker
	W. Todd Brooker
	Vice-President