Two maps showing the geologic features of the Western Snake River Basin, Idaho and locations of sample sites, wells, and cross-section locations. Four additional plates illustrate lithologic logs for the 17 petroleum test wells and 2 deep water wells selected for use in the study. The water wells were selected on the basis of total depth, quality of lithologic log, and location with respect to the lines of section. The sections A-A', B-B', C-C', and D-D' are shown on Plates 3 through 6, respectively. (p. 11 of report)