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
Muddy Creek (Lamine River) Muddy Creek (Lamine River) Muddy Creek is a stream in Johnson and Pettis Counties in the U.S. state of Missouri. It is a tributary of Lamine River. The stream headwaters arise in southeastern Johnson County just east of the community of Sutherland and Missouri Route 23 at . The stream flows northeast and enters Pettis County about three miles southeast of Whiteman Air Force Base. The stream continues to the northeast passing under Missouri Route 127 three miles south of LaMonte and under U.S. Route 50 three miles west of Sedalia. It crosses under U.S. Route 65 six miles north