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
Little Wabash River counties, about southeast of New Haven. In its upper course in Shelby County, the river is dammed to form Lake Mattoon and collects the short West Branch Little Wabash River, which flows for its entire length in Shelby County. Other tributaries include the Fox River, which joins it in Edwards County; the Elm River, which joins it in Wayne County; and the Skillet Fork, which joins it in White County. Little Wabash River The Little Wabash River is a tributary of the Wabash River in east-central and southeastern Illinois in the United States. Via the Wabash and Ohio rivers, it