Ph.D. (Washington State University, 1985), 44 years of experience in western North America, Northeastern Africa and the Central and Eastern Mediterranean in the fields of archaeology, paleoecology, and paleoclimatology, and geomorphology. He has been shedding vital, new light on past processes in arid environments, while at the same time helping to solve some of the problems facing environmental resource managers and planners today. Using plant remains recovered from ancient packrat nests (middens) and cave and aquatic contexts, pollen and charcoal from carefully dated stratigraphic sequences, he has been able to record the dynamics of vegetation change, fire regimes, surface and groundwater fluctuation, and changes in surficial (erosion and deposition) processes on local and regional scales in the Intermountain American West. Currently, he is engaged in study of the causes of past and current landscape erosion in southern Italy. In western Iran, he has been examining the impact of landscape erosion on lake chemistry during the Holocene. This science has been presented at meetings in Denver, Athens, Rome, and Tehran.