Maps. Trinity River. Plan and profile of Trinity River from Douglas City to Carrville, Calif., and tributaries, miscellaneous dam sites, topography by Frank Packard and E. J. Van Wormer, surveyed in 1934, 1935, and 1936; [maps]. Scale 1:31,680, contour interval on land 20 ft., contour interval on river surface 5 ft. n. p.