Southern Illinois Southern Illinois Southern Illinois (also known as "Little Egypt") is the southern third of the state of Illinois. The southern part of Illinois has a unique cultural and regional history. Part of downstate Illinois, the Southern Illinois region is bordered by the two most voluminous rivers in the United States: the Mississippi River and its connecting Missouri River to the west, and the Ohio River to the east and south with the Wabash as tributary. Southern Illinois' most populated city is Belleville at 44,478. Other principal cities include Alton, Centralia, Collinsville, Edwardsville, Effingham, O'Fallon, Harrisburg, Herrin, Mt. Vernon, Marion, and
Fox River (Illinois River tributary) and a spillway to the east. A small dam is present just a few miles south in downtown Rochester. The river then flows unobstructed through Burlington, where it joins the White River, and on to Wilmot. This is a popular and picturesque day-canoe trip never straying far from the road, but often just out of sight of it. Flooding is common on this section of the river, especially near Wheatland to the border. The river enters Illinois where it widens into a large area of interconnected lakes known as the Chain O'Lakes. Fox Lake is the largest village in this