Marshall, R. B. California (San Joaquin country) Peters quadrangle surveyed in 1912 in cooperation with the state of California , Scale [1:31680] Scale [1:5] Contour Interval 5 feet - Washington US geogological survey 1915 - 1 Map Coloured Map 52 x 42cm Datum is mean sea level Index Terms--Genre/Form: Topographic Map Dewey Class. No.: 912.794