Alta Mesa 10-Q 2017 Q2 Quarterly report

Exhibit 32.1

CERTIFICATION OF

CHIEF EXECUTIVE OFFICER

OF ALTA MESA HOLDINGS, LP

PURSUANT TO 18 U.S.C. SECTION 1350

In connection with this Quarterly Report on Form 10-Q of Alta Mesa Holdings, LP for the period ended June  30, 2017, I, Harlan H. Chappelle, President and Chief Executive Officer of Alta Mesa Holdings, LP, hereby certify pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.This Quarterly Report on Form 10-Q for the period ended June  30, 2017 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2.The information contained in this Quarterly Report on Form 10-Q for the period ended June  30, 2017 fairly presents, in all material respects, the financial condition and results of operations of Alta Mesa Holdings, LP for the periods presented therein.

Date: August  17, 2017

 /s/ Harlan H. Chappelle

Harlan H. Chappelle

President and Chief Executive Officer of Alta Mesa

Holdings GP, LLC, general partner of Alta Mesa Holdings, LP