The Shawnee National Forest is a United States National Forest located in the Ozark and Shawnee Hills of Southern Illinois, United States. Administered by the U.S.D.A. Forest Service, it consists of approximately 498,615 acres of federally managed lands. In descending order of land area it is located in parts of Pope, Jackson, Union, Hardin, Alexander, Saline, Gallatin, Johnson, and Massac counties. Forest headquarters are located in Harrisburg, Illinois.