Devils Tower (also Bear Lodge Butte) is a laccolithic butte composed of igneous rock in the Bear Lodge Mountains (part of the Black Hills) near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle Fourche River. It rises dramatically 1,267 feet (386 m) above the Belle Fourche River, standing 867 feet (265 m) from summit to base. The summit is 5,112 feet (1,559 m) above sea level. Devils Tower was the first declared United States National Monument, established on September 24, 1906, by President Theodore Roosevelt. The monument's boundary encloses an area of 1,347 acres.

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