by Thomas W. Dibblee, Jr. ; edited by John A. Minch. Relief shown by contours and spot heights. "Topographic base map from available USGS 7.5-minute quadrangle Pacheco Pass, CA 1955. Photorevised 1971. AMS 1758 II SW--Series V895." "First printing, July 2007." Includes location map, index to adjacent 7.5 minute quadrangles, and index to sources of geology, most recent 1973. Barry Keller honorary map. Includes "pertinent references", most recent 1999.