Mr. Timothy W. Byrne has been the Chief Executive Officer and President of United States Lime & Minerals, Inc., a holding company of U.S. Lime Company-St. Clair since December 8, 2000. Previously, Mr. Byrne served as President and Chief Executive Officer of United States Lime & Minerals Inc. from 1997 to 1998 and in various other positions including Senior Vice President, Chief Financial Officer and Vice President of Finance and Administration from 1990 to 1998. Prior to rejoining United States Lime & Minerals Inc. in 2000, Mr. Byrne served as President of Rainmaker Interactive, Inc., an Internet services and communications company focusing on strategy, marketing and technology. Mr. Byrne served as a Partner at a consulting and accounting firm in Washington, D.C. He has been a Director of United States Lime & Minerals, Inc. since 1991.