By:Tracey J. Felger, David M. Miller, Victoria E. Langenheim, and Robert J. Fleck

The Kelton Pass SE and Monument Peak SW 7.5′ quadrangles (NW Utah) are located entirely within southern Curlew Valley, which drains south into Great Salt Lake, and extends north into Idaho. Bedrock exposures form the Wildcat Hills and two small shield volcanoes. Exposed rocks and deposits are Permian to Holocene in age and include sandstone of the Permian Oquirrh Formation, tuffaceous sedimentary rocks of the Miocene Salt Lake Formation, Pliocene basaltic and dacitic lava flows, Pleistocene rhyolite and basalt, and Pleistocene and Holocene surficial deposits of alluvial, lacustrine, and eolian origin. Structures related to the Miocene Raft River detachment fault and Basin and Range extension also are present. New geophysical data and interpretations and new geochronology data for volcanic units improved insight into the tectonic and volcanic evolution of the area.