Illinois River County, Illinois, and across from Browning, it is joined by the Sangamon River, which passes through the state capital, Springfield, Illinois. The La Moine River flows into it approximately five miles (8 kilometers) southwest of Beardstown, which is south of Peoria and Pekin and north of Lincoln and Springfield. Near the confluence of the Illinois with the La Moine River, it turns south, flowing roughly parallel to the Mississippi across southwestern Illinois. Macoupin Creek joins the Illinois on the border between Greene and Jersey counties, approximately 15 miles (24 km) upstream from the confluence with the Mississippi. For the last
Southern Illinois River-to-River Conference approached by Benton, Herrin, Harrisburg, and West Frankfort for membership; these four schools were concerned over their small size relative to the other members of the South Seven Conference (where all four were then located) and sought out a conference more in line with their size. Massac County (then an independent school) was approached about becoming a member, and in 1993 the Southern Illinois River-to-River Conference was formed. At the start of the 2010-2011 school year Carterville left the Black Diamond Conference to join the Southern Illinois River-to-River Conference. Chester High School has taken their place in the Black Diamond