At top of plate: 'U.S. geographical surveys west of the one-hundredth meridian. Parts of California, S.E. Nevada, Arizona & S.W. Utah.' At bottom of plate: 'Expeditions of 1872 & 1873, under the command of 1st Lieut. Geo. M. Wheeler, Corps of Engineers, U.S. Army.' 'G. K. Gilbert, A. R. Marvine, E. E. Howell, geological assistants.' 'By order of The Honorable The Secretary of War, under the direction of Brig. Gen. A. A. Humphries, Chief of Engineers, U.S. Army.' Published by Government Printing Office. 2 map sections on 1 sheet. Scale: 1 inch to 8 miles.