Corbin J. Robertson, III joined the Board of Directors of GP Natural Resource Partners LLC in May 2013. Mr. Robertson has experience with investments in a variety of energy businesses, having served both in management of private equity firms and having served on several boards of directors. Mr. Robertson has served as a Co-Managing Partner of LKCM Headwater Investments GP, LLC and LKCM Headwater Investments 1 and 2, L.P.s, a private equity firm, since June 2011. He has served as the Chief Executive Officer of the general partner of Western Pocahontas Properties Limited Partnership, a land company with vast coal reserves, since May 2008, and has served on the Board of Directors of Western Pocahontas since October 2012. Mr. Robertson also co-founded Quintana Energy Partners, an energy-focused private equity firm in 2006, and served as a Managing Director thereof from 2006 until December 2010. Mr. Robertson is an owner of and has served on the Board of Directors for Quintana Minerals Corporation since October 2007. Quintana Minerals and its affiliates control a broad investment portfolio in the energy business that includes oil and gas operations, oil and gas service companies, coal fee mineral ownership and coal mining businesses, and coal service companies, among many others. Mr. Robertson previously served as Vice President-Acquisitions for GP Natural Resource Partners LLC from 2003 until 2005. Mr. Robertson also serves or has served on the Board of Directors of the general partner of Genesis Energy L.P., a publicly traded master limited partnership, as well as Quintana Maritime, a dry bulk shipping company, Corsa Coal Corp, a met coal producer, Buckhorn Energy Services, an energy waste service company, and LL&B Minerals, each of which is focused on the energy business. Mr. Robertson holds a BBA and BA from The University of Texas at Austin and an MBA from Harvard Business School.