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
Big Sandy River (Ohio River tributary) It joins the Ohio between Catlettsburg, Kentucky and Kenova, West Virginia, west of Huntington, West Virginia, at the common boundary between West Virginia, Kentucky, and Ohio. The river is navigable and carries commercial shipping, primarily coal mined in the immediate region. The name of the river comes from the presence of extensive sand bars. The Native American names for the river included "Tatteroa", "Chatteroi", and "Chatterwha" which had similar meaning to the English name. It was known to the Lenape as "Sikeacepe", meaning "Salt River", from the presence of salt licks on the river ("see": Licking River). The name "Big