Relief shown by hachures and spot heights. Prime meridian: Washington. Shows exploration routes, state borders. At lower left: "Issued Feb. 4th, 1878." "By order of the honorable, the Secretary of War, under the direction of Brig. Gen. A.A. Humphreys, Chief of Engineers, U.S. Army." Includes table of "dates of camps of river party in 1871." 1 map: 37 x 45 cm. This map is in the public domain. Please attribute access and use of this digitized map to the Stephen S. Clark Library, University of Michigan Library.