Bob Sinclair Illinois State Water Survey, Sr. ISWS modified this coverage in 1995. The source maps were rectified to the basemaps, and delineations were made on a mylar overlay. Line placements were enhanced using the USGS basemap and Landsat imagery. ISWS modified this coverage in 1995.
Data are polygons.
Coverage consists of 63 polygon units. Reproduction or redistribution of copyrighted digital data sets or products derived therefrom outside of licensee's organization or entity is expressly forbidden. The only exception is redistribution to consultants working for the licensee, and then only for purposes, related to work for the licensee. Such consultants may not further reproduce or redistribute these data sets. Any hardcopies utilizing DNR data sets shall clearly indicate their source.