'Geology by C.R. Longwell.' At top of map: 'U.S. Geological Survey Bulletin 798, plate 1.' Includes four colored cross-sections. 1:250,000 (W 115°00'--W 113°45'/N 36°45'--N 36°00'). Series: Bulletin (Geological Survey (U.S.) no. 798. Originally published as plate 1 in: Geology of the Muddy Mountains, Nevada, with a sections through the Virgin Range to the Grand Wash Cliffs, Arizona / by Chester R. Longwell. Washington, D.C. : Government Printing Office, 1928. (Bulletin ((Geological Survey (U.S.)), no. 798).