Devils Tower became the first U.S. national monument when Theodore Roosevelt proclaimed it protected in 1906.
Roosevelt issued the proclamation on September 24, 1906, using authority granted by the Antiquities Act of 1906. The law empowered presidents to protect objects of historic or scientific interest on federal land without waiting for Congress to create a national park.
Devils Tower is a striking igneous rock formation in northeastern Wyoming. It rises about 867 feet above the surrounding landscape and is sacred to several Indigenous nations, including the Lakota, Cheyenne, and Kiowa.
The landmark is commonly called Devils Tower, without an apostrophe, in its official name. It is sometimes confused with Mount Rushmore or the Grand Canyon, both of which later received federal protection through different designations and dates.