Devils Tower was the first U.S. national monument. Which U.S. state is it in?

Wyoming is the answer. Devils Tower National Monument is located in northeastern Wyoming, where its striking column-like igneous rock formation became the first U.S. national monument when President Theodore Roosevelt protected it in 1906 under the Antiquities Act.

Devils Tower in Wyoming

Devils Tower is in northeastern Wyoming. The landmark rises prominently above the surrounding landscape, making it one of the state’s most recognizable public-land features. Its location is central to the answer because Devils Tower National Monument is often associated with both Wyoming geography and early federal conservation history.

The First U.S. National Monument

Devils Tower was designated the first U.S. national monument in 1906. That status makes it different from a national park, since national monuments can be established to protect specific natural, cultural, or historic features. Its designation marked an early use of federal authority to preserve an important landmark.

Roosevelt and the Antiquities Act

President Theodore Roosevelt designated Devils Tower under the Antiquities Act. The law allowed presidents to protect significant public-land sites as national monuments. Roosevelt’s action made Devils Tower an early example of how the federal government could preserve distinctive natural formations and culturally important places.

The Tower’s Geologic and Cultural Importance

Devils Tower is known for its tall rock formation with column-like features, commonly described as igneous in origin. The site also has cultural and spiritual significance for Indigenous peoples, including tribes with long-standing connections to the area. Its importance comes from both its unusual geology and its role as a protected landscape with deep cultural meaning.