River mileages and drainage areas for Illinois streams—Volume 1, Illinois except Illinois River basin

River mileages are presented for points of interest on Illinois streams draining 10 square miles or more. Points of interest include bridges, dams, gaging stations, county lines, hydrologic unit boundaries, and major tributaries. Drainage areas are presented for selected sites, including total drainage area for any stream draining at least 100 square miles. The report is contained in two volumes. This volume (Volume I) includes Illinois except Illinois River basin.