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
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