by Thomas W. Dibblee, Jr. ; edited by John A. Minch. Relief shown by contours and spot heights. "Topographic base map from newest available USGS 7.5-minute quadrangle SANTA MARGARITA, CA 1965, DMA 1854 I NE -- Series V895, REVISED 1993." "First printing, June 2004." Includes quadrangle location map, index to adjacent 7.5 minute quadrangles, and index to sources of geology. Includes "pertinent references."