This is one of a series of maps that describe the geology and related natural resources of the Tooele 2° quadrangle. The purpose of this map is to describe on a regional scale the availability and chemical quality of surface water and to guide readers to more detailed site-specific information about the resource in this generally semiarid region. Most of the data used to compile this map were collected by the U.S. Geological Survey under cooperative programs with the Utah Departments of Natural Resources and Transportation. Those data are available in the files of the U.S. Geological Survey, Water Resources Division, Salt Lake City, Utah.