Southern Illinois the Ozarks of Missouri, is chiefly in southern Jackson, Union, northern Alexander and Johnson counties. The eastern area, more closely related to the Wabash Valley Seismic Zone, is mostly in northern Pope, southern Saline, Gallatin, eastern Johnson and southern Williamson counties. The Shawnee National Forest covers a large territory, including seven wilderness areas: Garden of the Gods, Bay Creek, Clear Springs, Bald Knob, Burden Falls, Lusk Creek, and Panthers Den. Of southern Illinois' rivers, only the Mississippi and the Ohio are navigable for modern commerce. The Big Muddy River, Marys River, Saline River and Cache River run their courses in
Embarras River (Illinois) southeastern Champaign; the southern portion of the University of Illinois campus, including the small creek near the Vet Med Building; and Meadowbrook Park in south Urbana. The Embarras flows generally southward through Douglas, Coles, Cumberland, and Jasper Counties. In Jasper County, it turns southeast for the remainder of its course through Richland, Crawford, and Lawrence Counties. Portions of the river's lower course have been straightened and channelized. It joins the Wabash River southwest of Vincennes, Indiana. Along its course, the Embarras passes the towns of Villa Grove, Camargo, Charleston, Greenup, Newton, Ste. Marie, and Lawrenceville. The United States Board on