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 the original Illinois State capitol at Kaskaskia, Marys River was the site of early settlements in the interior of Illinois. It also served both as an avenue for transportation into the interior of Illinois, and as a barrier to land transportation.
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.