President Theodore Roosevelt established the first national monument, Devils Tower in Wyoming, on September 24, 1906. The monument's boundary encloses an area of 1,347 acres.

It (Devils Tower) is a laccolithic butte composed of igneous rock in the Bear Lodge Mountains in northeastern Wyoming. The monolith known as Devils Tower rises 1,267 feet above Belle Fourche River. What we actually see today at the Devils Tower National Monument is the remains of an ancient volcanic structure.

Referred to by several tribes as Bears Lodge, it is a site of worship for many American Indians. Specifically, tribes including the Arapaho, Crow, Cheyenne, Kiowa, Lakota, and Shoshone had cultural and geographic ties to the monolith before non-Native Americans reached the state of Wyoming.

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