Devils Tower was the first U.S. national monument, proclaimed in 1906.
President Theodore Roosevelt used the Antiquities Act to establish Devils Tower National Monument in Wyoming on September 24, 1906. The act gave presidents authority to protect significant historic, prehistoric, and scientific objects on federal land.
Devils Tower is a striking igneous rock formation in the Black Hills region. Its columns and cultural significance made it an early example of how the national-monument designation could protect natural as well as archaeological resources.
The monument predates the National Park Service by ten years. Several other early national monuments, including Grand Canyon, Petrified Forest, and Muir Woods, were later administered by the NPS or eventually became national parks.