This report, prepared by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, is the twelfth in a series of reports that describe the water resources of the western basins of Utah. (See fig. 1.) Its purpose is to present available hydrologic data on the Pilot Valley area, to provide an evaluation of the potential for water-resource development in the area, and to identify studies that would improve understanding of the area's water supply.