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
Southern Illinois River-to-River Conference Southern Illinois River-to-River Conference The Southern Illinois River-to-River Conference (SIRR) is a high school athletic conference represented by 12 schools in southern Illinois. The conference is divided into two divisions. While technically in the same conference each division crowns its own champion, and each winner is regarded as the conference champion as if they were in two separate conferences. Schools are only required to play other schools within their own division although cross-divisional play is very common. Seven of the charter members of the River-to-River Conference were members of the old Southwest Egyptian Conference. Around 1991, the Southwest Egyptian was