In the 1870s logging of the state's native oak, hickory, and pine forests began. Sawmills were common, but by the 1920s they had disappeared. By then so had much of the state's native forests. In 1939 President Franklin Delano Roosevelt signed the MTNF into existence. In March 1933, he also created the Civilian Conservation Corps (CCC). In the area that would later become Mark Twain National Forest, hundreds of young men at over fifty CCC sites worked at building roads and planting hundreds of acres of pine trees. Many of their contributions can still be visited and enjoyed today.