Oregon County is a county located in the southern portion of the U.S. state of Missouri. As of the 2020 census, the population was 8,635. Its county seat is Alton. The county was officially organized on February 14, 1845, and was named for the Oregon Territory in the northwestern United States.

Mark Twain National Forest (MTNF) is a U.S. National Forest located in the southern half of Missouri, composed of nine disconnected parcels. MTNF was established on September 11, 1939. It is named for author Mark Twain, a Missouri native. The MTNF covers 3,068,800 acres (12,419 km2) of which 1,506,100 acres (6,095 km2) is public owned, 78,000 acres (320 km2) of which are Wilderness, and National Scenic River area. MTNF spans 29 counties and represents 11% of all forested land in Missouri. MTNF's nine tracts are divided into six distinct ranger districts: Ava-Cassville-Willow Springs, Eleven Point, Houston-Rolla, Cedar Creek, Poplar Bluff, Potosi-Fredericktown, and the Salem. Its headquarters are in Rolla, Missouri.