37 x 50 cm. Relief shown by hachures and spot heights "Atlas sheet no. 77(B)." "Issued May 7th 1877." "Expeditions of 1871 & 1786 under the command of 1st. Lieut. Geo. M. Wheeler, Corps of Engineers, U.S. Army." "Weyss, Herman & Lang, del." "By order of the honorable the Secretary of War." "Under the direction of Brig. General A. A. Hunphreys, Chief of Engineers, U. S. Army." "2nd. Ed. June 30th, 1881." Original publisher: U.S. Geographical Surveys West of the 100th Meridian, Scale: 1 inch to 4 miles or 1: 253440.