Devils Tower is a butte composed of igneous rock in the Bear Lodge Ranger District of the Black Hills in Crook County, Wyoming. It rises 1,267 feet above the Belle Fourche River, standing 867 feet from summit to base. The summit is 5,112 feet above sea level. Devils Tower was the first United States national monument, established on September 24, 1906, by President Theodore Roosevelt. The monument’s boundary encloses an area of 1,347 acres.