Gray Thompson is an Emeritus Professor of Geology at the University of Montana where he taught Introductory Geology, Mineralogy, Summer Field Mapping and graduate courses in Clay Mineralogy and Shale Petrology. He has published over 20 research papers in international journals, mostly co-authored with his students. He also has authored many articles published in international climbing magazines and journals and has been the subject of other articles in these publications. Dr. Thompson is a mountaineer and professional guide with first ascents--many with Jon Turk--of peaks and routes in the Rocky Mountains, Alaska, the Yukon, Baffin Island, the Alps, the Karakoram and the Himalayas. He and Dr. Turk took many of the photographs in his texts on their climbing trips and expeditions over the last 18 years. Dr. Thompson earned a bachelor's degree in geology from Bates College, a master's in geology-geochemistry/petrology from Dartmouth College and a Ph.D. in geochemistry/clay mineralogy/petrology from Case Western Reserve University.