Plate 1: Index map of rock salt deposits in the United States. Plate 2: Map showing aggregate thickness of salt beds in the Salina formation or group / Modified from C.R. Fettke (1955), W.L. Kreidler (1957), K.K. Landes (1945; 1951), and J.F. Pepper (1947). Plate 3: Map showing depth below sea level of top of uppermost salt bed in the Salina formation or group / Modified from C.R. Fettke (1955), W.L. Kreidler (1957), K.K. Landes (1945), and J.F. Pepper (1947). Plate 4: Map of the gulf coast embayment showing location of salt domes and the Louann salt. Plate 5: Map showing aggregate thickness of salt in Permian Basin of Kansas, Oklahoma, Texas, and New Mexico / Adapted from maps and reports by N.W. Bass 1926, Hoots 1925, Lee 1956, and unpublished maps by P.T. Hayes, U.S. Geological Survey. Plate 6: Map of Paradox Basin area showing thickness of salt-bearing rocks of Paradox member of Hermosa formation, and their relation to major structural and physiographic features / Map modified from compilation by Elmer H. Baltz, U.S. Geological Survey. Includes bibliographical references (pages 78-87) and index.