Territory of the United States from the Mississippi River to the Pacific Ocean : originally prepared to accompany the reports of the explorations for a Pacific railroad route ; made in accordance with the 10th & 11th sections of the Army Appropriation Act of March 3rd 1853 ; compiled from authorized explorations and other reliable data / by Lieut. G. K. Warren, Top'l. Eng'rs in the Office of Pacific R.R. Surveys War Dept. under the direction of Bv't. Major W.H. Emory, Top'l Eng'rs in 1854 ; Capt. A.A. Humphreys, Top'l Eng'rs in 1854-1858 ; Recompiled and redrawn under the direction of Chief of Corps of Engineers / by Edward Freyhold 1865-66-67-68.