'Department of the Interior, U.S. Geological Survey. Water-supply paper 2320-a, plate 4.' 'Prepared in cooperation with the Clark County Department of Comprehensive Planning.' 'Base from U.S. Geological Survey 1:100,000 , Boulder City, Ariz.-Nev., Las Vegas, Nev.-Calif., Mesquite Lake, Nev.-Calif., 1978, Lake Mead, Nev.-Ariz., 1979.' 'Geology from Malmberg (1965); Longwell and others (1965); Bell and Smith (1980); and J. R. Harrill, 1976.' Shows township and range lines. Scale 1:100,000 (W 115°30´--W 115°00´/N 36°30´--N 36°00´). Series: U.S. Geological Survey water-supply paper 2320-A. Originally published as plate 4 of Ground-water conditions in Las Vegas Valley, Clark County, Nevada. Part I. Hydrogeologic framework / by Russell W. Plume, published by the U.S. Geological Survey in 1989 as Water-supply paper 2320-A.