United States Lime & Minerals Cultura de la Empresa

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.

Mr. M. Michael Owens has been Secretary and Treasurer at United States Lime & Minerals, Inc. since August 9, 2002. Mr. Owens served as the Chief Financial Officer and Vice President of United States Lime & Minerals, Inc. from August 9, 2002 to September 18, 2017 and also served as its Principal Accounting Officer. Mr. Owens served as Chief Financial Officer, Principal Accounting Officer, Vice President, Secretary and Treasurer of IonSpec Corporation. Prior to joining United States Lime & Minerals Inc., he served as Vice President of Finance at Sunshine Mining and Refining Company (Sunshine), a silver mining company, where he held various financial and accounting officer positions from 1983 to 2002. He has over 25 years of financial and accounting experience.

Mr. Michael L. Wiedemer has been Vice President and Chief Financial Officer of United States Lime & Minerals, Inc. since September 18, 2017. Mr. Wiedemer has served as Corporate Controller for TearLab Corp. since September 2015. From October 2009 to September 2015, Mr. Wiedemer held various positions, including Corporate Controller and Chief Accountant, at Peerless Manufacturing Company (PMFG). Prior to joining PMFG, Mr. Wiedemer was an Audit Manager with Grant Thornton LLP. He is a Certified Public Accountant.

Mr. David P. Leymeister has been Vice President of Sales and Marketing at United States Lime & Minerals. Inc. since joining it in January 2008. Mr. Leymeister served as an Executive Officer of United States Lime & Minerals Inc. since March 2008. He has over 30 years of sales experience, including 12 years in sales management. From January 2003 to January 2008, Mr. Leymeister served as a Vice President - Sales for Steelscape, a coated sheet steel producer on the west coast. Prior to January 2003, he held various sales and sales management positions within Bethlehem Steel.

Mr. Russell W. Riggs has been a Vice President of Production at United States Lime & Minerals, Inc. since joining it in January 2006 and has been its Executive Officer since February 2006. Mr. Riggs has over 25 years of experience in the lime and limestone industry. Since 2005, he served as Consultant for various engineering companies and also as a Project Manager for a specialty minerals based company. Prior to 2005, Mr. Riggs held various plant and operations management positions with Chemical Lime Company.