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 River (Nevada) National Wildlife Refuge Complex. In another effort to help protect and preserve the fragile habitats in the Muddy Springs area, the Southern Nevada Water Authority (SNWA) and various environmental associations have organized an effort to conserve these species. The area was part of the Native American Paiute peoples homeland for centuries, with the Mojave to the south. "Moapa" is a Southern Paiute language word meaning "muddy"; although "Moapa River" was formerly the official name, local usage tended to translate the name, and it was made official in 1960. The Old Spanish Trail originally followed the Virgin River all the way