Big Muddy River Big Muddy River The Big Muddy River is a river in southern Illinois. It joins the Mississippi River just south of Grand Tower. The Big Muddy has been dammed near Benton, forming Rend Lake. The Big Muddy has a mud bottom for most of its length. The Big Muddy drains a watershed. In 1995, water quality was assessed as "fair" to "good". Pollution sources include agricultural practices, mining and municipalities. The watershed of the Big Muddy was covered by the Illinoian Glacier about 300,000 to 132,000 years before present. The Big Muddy basin formed after the retreat of that glacier.
Muddy, Illinois Muddy, Illinois Muddy is a small incorporated village located in the Harrisburg Township in Saline County, Illinois, United States. The population was 78 at the 2000 census. During the 19th century, the site of Muddy was home to a small settlement known as Robinson's Ford, which was among the communities considered for the seat of Saline County after the county's creation in the 1840s. The modern village of Muddy had its start as a mining settlement established by the Harrisburg Big Muddy Coal Company, for which it was named, in 1903. The mine was sold to the larger O'Gara Coal