Big Muddy River The Big Muddy was not covered by the Wisconsin Glacier, about 70,000 to 10,000 years before present. However, during the melting of that glacier, the level of the Mississippi River was much higher. Water backed up into the Big Muddy Basin, forming a lake much like the artificial Rend Lake but covering a larger area. The ancient lake silted in, forming a flat bottom. After the melting of the Wisconsinan glacier, the level of the Mississippi dropped, allowing the lake to drain. A new channel formed within the old lake bed. This channel meandered in the flat bottom of the
Illinois River was relocated to the present site of Creve Coeur, near Peoria, where the Jesuits relocated. The Peoria Riverfront Museum contains a gallery, "Illinois River Encounter," that attempts to interpret the museum through an aquarium tank and displays of the river's geology, ecology, social history, engineering, and commercial use. From 1905 to 1915, more freshwater fish were harvested from the Illinois River than from any other river in the United States except for the Columbia River. The Illinois River was once a major source of mussels for the shell button industry. Overfishing, habitat loss from heavy siltation, and water pollution have