Shawnee National Forest is the largest, most diverse natural treasure in Illinois. In contrast to the gently rolling farm lands to the north, the 270,000 acres of Shawnee National Forest lie in the rough, unglaciated areas of southern Illinois known as the Ozark and Shawnee Hills. This area between the Mississippi and Ohio Rivers boasts an unusual combination of five natural ecological divisions. In addition to an astonishing variety of trees and plants, many species of wildlife live on the Shawnee, including at least 49 species of mammals, 253 birds, 52 reptiles, 57 amphibians, and 109 fish. From ancient bald cypress trees and tupelo wetlands to dry upland hardwood slopes, the Shawnee is home to an extraordinary diversity of species.