Nevada Bureau of Mines & Geology • Maps & Data
Oregon Department of Geology and Mineral Industries • Publications • Index to Geologic Maps of Oregon by USGS Topographic Quadrangle Name, 1883-1996 University of Oregon Libraries
Washington Geological Survey • Geologic Maps • Publications and Maps
Links to State Geological Surveys Association of American State Geologists Most have lists of and/or links to their geological maps
List of U.S. Geological Survey Geologic and Water-Supply Reports and Maps for [various states] Digitized versions via Hathitrust:
Geologic Map Index of [various states] (USGS) Search OneSearch-Books & Media to find the call number.