based on Hansel and Johnson, 1996 ; revised from Lineback 1979, Killey and Lineback, 1983, Berg and others, 1984, and Berg and others, 1985 ; digitally adapted by Barbara J. Stiff
Date
2000
Series
Illinois State Geological Survey open file series ; 2000-7
prepared by J.D. Love [and others] ; United States Department of the Interior, Geological Survey ; prepared with the cooperation of the Geological Survey of Wyoming and the Department of Geology, University of Wyoming
Date
1945
Series
Oil and gas investigations. Preliminary chart ; 14
prepared by the Exploration Dept. of Shell Oil Co. ; edited by T. D. Cook and A. W. Bally ; compiled by S. Milner...[and others] ; cartography and drafting by W. C. Heuer...[and others]