This is Dr. William A. Clemens, a Professor in the Department of Integrative Biology at U. C. Berkeley, and a Faculty Curator of the UCMP. He and Dr. Carl Swisher of the Berkeley Geochronology Center received the National Science Foundation grants that made this field trip possible. Bill and many of his students have worked in Montana over the last 30 years, and he was the mastermind and organizer of the trip. Bill's research mostly centers around early mammals. In this photo he is brushing small fossils out of a screen, hoping to find some mammal teeth.