Devils Tower (also known as Bear Lodge Butte) is a butte, possibly laccolithic, composed of igneous rock in the Bear Lodge Ranger District of the Black Hills, near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle Fourche River. It rises 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 United States national monument, established on September 24, 1906 by President Theodore Roosevelt. The monument's boundary encloses an area of 1,347 acres (545 ha).

The name Devil's Tower originated in 1875 during an expedition led by Colonel Richard Irving Dodge, when his interpreter reportedly misinterpreted a native name to mean "Bad God's Tower". All information signs in that area use the name "Devils Tower"

Trappers may have visited Devils Tower, but they left no written evidence of having done so. The first documented Caucasian visitors were several members of Captain William F. Raynolds's 1859 expedition to Yellowstone. Sixteen years later, Colonel Richard I. Dodge escorted an Office of Indian Affairs scientific survey party to the massive rock formation and coined the name Devils Tower Recognizing its unique characteristics, the United States Congress designated the area a U.S. forest reserve in 1892.

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