Marys River (Illinois) Marys River (Illinois) Marys River is a tributary of the Mississippi River in Illinois. It drains a small watershed between the Big Muddy River and the Kaskaskia River. It joins the Mississippi just southeast of Chester, near Kaskaskia. Because of its proximity to Kaskaskia — the capital of Illinois Territory and the first capital of the State of Illinois — Marys River was the site of early settlements leading into the interior of Illinois. Marys River is approximately in length. The following cities and towns are in the Marys River basin: Parts of the following counties are in the Mary's
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