The purpose of this study is to provide geologic information important in assessing ground-water resources and siting water wells in the Snyderville basin. This geologic study was one phase of a cooperative and more comprehensive water-resource investigation. Subsequent phases conducted by the U.S. Geological Survey Water Resources Division (USGS WRD), focused on the hydrology of the Snyderville basin. The information presented in this report is generalized and is not intended to substitute for site-specific investigations. Future detailed studies will add to the understanding of the geology and ground-water resources of the study area and supplement the information presented herein. 59 pages + 15 plates