In the 1870s, citizens of southern Missouri began an era of extensive logging of the state's native oak, hickory, and pine forests. Lumber mills were commonplace, but by the 1920s they had disappeared, along with much of the state's native forests. Thus, in 1939, President Franklin D. Roosevelt signed the MTNF into existence. In March 1933, he also created the Emergency Conservation Work Act, better known as the Civilian Conservation Corps (CCC). In the area that would later become the Mark Twain National Forest, hundreds of young men at over 50 CCC sites worked at building roads and planting hundreds of acres of pine to preserve and enhance the natural resources of southern Missouri. Many of their contributions can still be visited and enjoyed today including the Rolla Ranger Station Historic District and Winona Ranger Station Historic District.