Illinois River 20 miles (32 km) of its course, the Illinois is separated from the Mississippi River by only about five miles, by a peninsula of land that makes up Calhoun County. The Illinois joins the Mississippi near Grafton, approximately 25 miles (40 km) northwest of downtown St. Louis and about 20 miles upstream from the confluence of the Missouri River and the Mississippi. South of Hennepin, the Illinois River is following the ancient channel of the Mississippi River. The Illinoian Stage, about 300,000 to 132,000 years ago, blocked the Mississippi near Rock Island, diverting it into its present channel. After the
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