Devils Tower (Lakota: Mato Tipila, which means “Bear Lodge”) is a monolithic igneous intrusion or volcanic neck located in 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 surrounding terrain and the summit is 5,112 feet (1,558 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 (5.45 km2).
In recent years about 1% of the Monument's 400,000 annual visitors climb Devils Tower, mostly through traditional climbing techniques.

• en.wikipedia.org/wiki/Devils_Tower_National_Monument