United States Lime & Minerals (USLM) 10-K 2015 FY Annual report

EXHIBIT 32.1

SECTION 1350 CERTIFICATION BY THE CHIEF EXECUTIVE OFFICER

I, Timothy W. Byrne, Chief Executive Officer of United States Lime & Minerals, Inc. (the “Company”), hereby certify that, to my knowledge:

(1)The Company’s Annual Report on Form 10‑K for the year ended December 31, 2015 (the “Form 10‑K”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(2)The information contained in the Form 10‑K fairly presents, in all material respects, the financial condition and results of operations of the Company.

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Dated: March 4, 2016	/s/ Timothy W. Byrne
	Timothy W. Byrne
	President and Chief Executive Officer