The two reports in this Special Study provide critical geologic and paleoseismic information on the Oquirrh fault zone, a Quaternary fault in eastern Tooele County, west-central Utah. The Oquirrh fault zone has long been recognized as a potential source of large earthquakes which could affect military and hazardous waste facilities, nearby towns, and populous areas of the more distant central Wasatch Front.  64 pages + 2 plates