Board of Managers

Board of Managers

The Board of Managers of Sierra Minerals, LLC is comprised of Mr. Elli M. A. Mills, Chief Executive Officer, and Ms. Diane M. Hendricks, Mr. Karl W. Leo, and Mr. Jon Coulter.


Ms. Diane Hendricks

Ms. Diane Hendricks, Board of Managers


Ms. Hendricks is the Chairman of the Board, Founder, and sole owner of ABC Supply, Inc. of Beloit, Wisconsin whose current annual sales exceed $12,000,000,000. She is also Chairman and Owner of Hendricks Holdings, Inc. which has a diverse portfolio of wholly-owned businesses in the fields of manufacturing, distribution, real estate development, construction, recycling, and life sciences. Forbes has ranked Ms. Hendricks as the highest net worth self-made woman in the United States.

Mr. Karl Leo

Mr. Karl Leo, Board of Managers


Mr. Leo is an investor, business executive, board member, and lawyer. He serves as Vice - President, Chief Legal Officer, and Member of the Board of Directors of ABC Supply Co., Inc. (the largest distributor of roofing, siding, and related products in the United States). Mr. Leo also serves as VP and CLO of Hendricks Holding Company, Inc., the private family investment company affiliated with ABC by common ownership. He is a founder, co-owner, director, and officer of The Westmoreland Company, Inc., a private developer of industrial real estate throughout North America. Mr. Leo is the founder and President of Leo Law Firm, a business law firm, located in Huntsville, Alabama. Mr. Leo also serves on the boards of advisors, directors, or managers or as an ambassador of Duke University School of Law, Capital Midwest Fund III and IV, Gem Pharmaceuticals, Hudson - Alpha Biotechnology Institute, Simple Helix, and US Submergent Technologies, among other organizations. Mr. Leo graduated from the University of Redlands (B.A.) and Duke University School of Law. (J.D.)

Mr. Jon Coulter

Mr. Jon Coulter, Board of Managers


Mr. Coulter is Managing Director at Hendricks Holding Company, Inc. (“HHC”) and has responsibility for several HHC portfolio companies, including Federal Heath Sign Company, Garick LLC, NorthStar Medical Technologies LLC, and Starlings Entertainment. Before joining Hendricks Holding Company, Mr. Coulter was an investment banker at Robert W. Baird & Co. (“Baird”) and a Principal at Baird Capital Partners, the private equity arm of Baird. He previously was an investment banker at Cleary Gull, Inc. Mr. Coulter was an officer in the U.S. Air Force and served twelve years as Instructor Pilot and Operations Staff Officer. He earned a Bachelor of Science from Purdue University and an M.B.A. from the University of Wisconsin – Madison.