EXHIBIT 31.1

      RULE 13a-14(a)/15d-14(a) CERTIFICATION BY THE CHIEF EXECUTIVE OFFICER

I, Timothy W. Byrne, certify that:

1.  I have reviewed this quarterly report on Form 10-Q of United States Lime &
    Minerals, Inc.;

2.  Based on my knowledge, this report does not contain any untrue statement of
    a material fact or omit to state a material fact necessary to make the
    statements made, in light of the circumstances under which such statements
    were made, not misleading with respect to the period covered by this report;

3.  Based on my knowledge, the financial statements, and other financial
    information included in this report, fairly present in all material respects
    the financial condition, results of operations and cash flows of the
    registrant as of, and for, the periods presented in this report;

4.  The registrant's other certifying officer and I are responsible for
    establishing and maintaining disclosure controls and procedures (as defined
    in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:

    a)   Designed such disclosure controls and procedures, or caused such
         disclosure controls and procedures to be designed under our
         supervision, to ensure that material information relating to the
         registrant, including its consolidated subsidiaries, is made known to
         us by others within those entities, particularly during the period in
         which this report is being prepared;

    b)   Evaluated the effectiveness of the registrant's disclosure controls and
         procedures and presented in this report our conclusions about the
         effectiveness of the disclosure controls and procedures, as of the end
         of the period covered by this report based on such evaluation; and

    c)   Disclosed in this report any change in the registrant's internal
         control over financial reporting that occurred during the registrant's
         most recent fiscal quarter that has materially affected, or is
         reasonably likely to materially affect, the registrant's internal
         control over financial reporting; and

5.  The registrant's other certifying officer and I have disclosed, based on our
    most recent evaluation of internal control over financial reporting, to the
    registrant's auditors and the audit committee of the registrant's board of
    directors (or persons performing the equivalent functions):

    a)   All significant deficiencies and material weaknesses in the design or
         operation of internal control over financial reporting which are
         reasonably likely to adversely affect the registrant's ability to
         record, process, summarize, and report financial information; and

    b)   Any fraud, whether or not material, that involves management or other
         employees who have a significant role in the registrant's internal
         control over financial reporting.

Dated:  May 11, 2004              /s/  Timothy W. Byrne
                                  -------------------------------------
                                  Timothy W. Byrne
                                  President and Chief Executive Officer