About 9,760,000 results
Illinois River - Wikipedia
Illinois River | Map, Tributaries, History, & Facts | Britannica
Illinois River - WorldAtlas
Illinois River - Natural Atlas
Illinois River - Rivers.gov
Map of the Illinois River basin | U.S. Geological Survey - USGS.gov
Illinois River nautical chart and water depth map - Fishermap
Illinois River - Google My Maps
Illinois Rivers and Streams