Southwestern Colorado [cartographic material] / U.S. Geographical Surveys West of the 100th Meridian.Geographical Surveys West of the 100th Meridian (U.S.)[approximately 1876]"Atlas sheet no. 61(C).""Expeditions of 1874-1875 under the command of 1st. Lieut. Geo. M. Wheeler, Corps of Engineers, U.S. Army.""J.C. Spiller, del."Relief shown by hachures and spot heights.cartographic