Marys River (Illinois) River basin: 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
Vermilion River (Illinois River) Vermilion River (Illinois River) The Vermilion River is a tributary of the Illinois River in the state of Illinois, United States. The river flows north, in contrast to a second Vermilion River in Illinois, which flows south to the Wabash River. The Illinois and Wabash rivers each have a tributary named the Little Vermilion River as well. The north-flowing Vermilion River and the south-flowing Middle Fork Vermilion River run on what is close to a straight line between Oglesby and Danville. In presettlement times, the two rivers drained an upland marsh near Roberts. It is possible that early settlers regarded