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
Vermilion River (Illinois River) these as a single river that flowed in two directions. It is also possible that, in early settlement times, these rivers formed a canoe route between the Illinois River and Wabash River, with a portage through the marshes near Roberts. This may explain why the two rivers have the same name. The north-flowing Vermilion flows in a northerly direction from its origin in Livingston and Ford counties in north central Illinois, eventually emptying into the Illinois River, near Oglesby. Perhaps it is best known for its stretch of whitewater between Lowell and Oglesby, Illinois, which is one of few found