This report and accompanying maps and database address the geologic and geophysical character of a block of ten 7.5’ quadrangles that span the San Gorgonio Pass region. The study culminates more than four decades of intermittent geologic and geophysical mapping investigations by the U.S. Geological Survey (USGS). Published results from these investigations fall into two categories: (1) specialized reports that focus on spatially isolated parts of the Pass region and respond to specific USGS mission activities (Mineral Resources, Earthquake Hazards, and Water), and (2) tectonic synthesizes that summarize the structural evolution of the Pass region. The current report provides geologic details not included in the previous publications, and provides geologic information for areas between isolated areas examined for the earlier publications.