Beckwith, E. G., 1854, Report of explorations for a route for the Pacific Railroad: U.S. Pacific R.R. Explor., v. 2, 128 p. Cashion, W. B., 1973, Geologic and structure map of the Grand Junction Quadrangle, Colorado: U.S. Geol. Survey Misc. Inv. Ser. Map I-736 [reprinted 1979]. Cater, F. W., 1970, Geology of the salt anticline region in southwestern Colorado: U.S. Geol. Survey Prof. Paper 637, 80 p. Colorado State Planning Commission, 1959, Colorado Year Book, 1956-1958: Denver, 871 p. Dellenbaugh, F. S., 1902, The romance of the Colorado River: New York, G. P. Putnam’s Sons, 399 p. [reprinted 1962 by Rio Grande Press, Chicago, Ill.] Hamilton, D. L., 1956, Colorado National Monument, past and present: Intermountain Assoc. Petroleum Geologists, 7th Ann. Field Conf. Guidebook, p. 48-49. Hansen, W. R., 1969, The geologic story of the Uinta Mountains [with graphics by John R. Stacy]: U.S. Geol. Survey Bull. 1291, 144 p. Hayden, F. V., 1877, Report of progress for the year 1875: U.S. Geol. and Geog. Survey Terr., embracing Colorado and parts of adjacent territories, 827 p., 70 pls., 67 figs. Hunt, C. B., 1969, Geologic history of the Colorado River, _in_ The Colorado River region and John Wesley Powell: U.S. Geol. Survey Prof. Paper 669, p. I-IV, 59-130. Jennings, J. D., 1970, Canyonlands—aborigines: Naturalist, v. 21, Summer, Spec. Issue 2, p. 10-15. Lohman, S. W., 1960, Geology of west-central Colorado, _in_ Guide to the geology of Colorado: Geol. Soc. American, Rocky Mtn. Assoc. Geologists, and Colorado Sci. Soc., p. 66, 82-84 [with J. R. Donnell], 86-91. —— 1961, Abandonment of Unaweep Canyon, Mesa County, Colorado, by capture of the Colorado and Gunnison Rivers: U.S. Geol. Survey Prof. Paper 424-B, art. 60, p. B144-B146, fig. 60-1. —— 1963, Geologic map of the Grand Junction area, Colorado: U.S. Geol. Survey Misc. Inv. Ser. Map I-404. —— 1965a, Geology and artesian water supply of the Grand Junction area, Colorado: U.S. Geol. Survey Prof. Paper 451, 149 p. —— 1965b, The geologic story of Colorado National Monument [with graphics by John R. Stacy]: Fruita, Colo., Colorado and Black Canyon Natural History Assoc., 56 p. —— 1974, The geologic story of Canyonlands National Park, with graphics by John R. Stacy: U.S. Geol. Survey Bull. 1327, 126 p. —— 1975, The geologic story of Arches National Park, with graphics by John R. Stacy: U.S. Geol. Survey Bull. 1393, 113 p. Look, Al, 1961, John Otto and the Colorado National Monument: Denver, Colo., Denver Westerners, Inc., 80 p., [second edition 1962 by Sandstone Publishing Co., Grand Junction, Colo.]. Newman, W. L., 1976, Geologic time—the age of the Earth: U.S.