Mark Twain National Forest is a U.S. National Forest located in the southern half of Missouri. MTNF was established on September 11, 1939. It is named for author Mark Twain, a Missouri native. The MTNF covers 3,068,800 acres of which 1,506,100 acres is public owned, 78,000 acres of which are Wilderness, and National Scenic River area. MTNF spans 29 counties and represents 11% of all forested land in Missouri. MTNF is divided into six distinct ranger districts: Ava-Cassville-Willow Springs, Eleven Point, Houston-Rolla, Cedar Creek, Poplar Bluff, Potosi-Fredericktown, and the Salem. The six ranger districts actually comprise nine overall unique tracts of forests. Its headquarters are in Rolla, Missouri.
Some unique features of the Mark Twain include Greer Spring, which is the largest spring on National Forest land and part of the Eleven Point National Scenic River with an average daily flow of 214 million U.S. gallons. The public can also visit the Glade Top Trail National Scenic Byway, which offers views of over 30 miles to the Boston Mountains in Arkansas. The 350-mile Ozark Trail system winds through much of the National Forest.