Map PDF PDF of Aquifer sensitivity of the basal sand and gravel of the middle Illinois … General Information: Description One 40" x 45" map sheet; contains map, legend; descriptive text, and 2 figures. Publication Details: Publication Date 2015 Authors Richard C. Berg E. Donald McKay III Barbara J. Stiff Contributors Barbara J. Stiff Jennifer E. Carrell Deete M. Lund Brittany M. Walbright Map Details: Series ID IMAP 20 Theme Aquifer Sensitivity Scale Category Regional Scale 1:62,500 Ordering Information https://shop.inrs.illinois.edu/map-series.html#30