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 San Luis Dam, CA 1969, photoinspected 1978, DMA 1758 II SE--Series V895; Volta , CA 1960, photoinspected 1971, AMS 1758 III 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 1974. Includes "pertinent references", most recent 1999.