Exhibit 32.1

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
PURSUANT TO 18 U.S.C. § 1350  AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of Reef Oil & Gas Income and Development Fund III, L.P.  (the Partnership) on Form 10-K for the fiscal year ended December 31, 2011 as filed with the Securities and Exchange Commission on the date hereof (the Report), I, Michael J. Mauceli, principal executive officer of Reef Oil & Gas Partners, L.P., the managing general partner of Reef Oil & Gas Income and Development Fund III, L.P., certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(1)                                  The Report 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 the Report fairly presents, in all material respects, the financial condition and results of operations of the Partnership.

This certification accompanies the Report pursuant to §906 of the Sarbanes-Oxley Act of 2002 and shall not, except to the extent required by the Sarbanes-Oxley Act of 2002, be deemed filed by the Partnership for purposes of §18 of the Securities Exchange Act of 1934, as amended.

A signed original of this written statement required by §906 has been provided to the Partnership and will be retained by the partnership and furnished to the Securities and Exchange Commission or its staff upon request.