Answer: Devils Tower

At the turn (beginning) of the 20th century, there was a rising awareness in American culture that the vast number of ruins, artifacts, and places of historic or geological interest wouldn’t preserve themselves and the continual expansion of the population and resulting land development was a permanent and pressing threat. As a result, the U.S. Congress passed the Antiquities Act of 1906, signed into law by President Theodore Roosevelt, to protect everything from places of historical significance to Native American ruins and naturally occurring geological structures out West.

In fact, the first thing that President Roosevelt granted the protection and designation of National Monument to deftly combined both the protection of a natural geological structure and a place with significant history for many different Native American tribes: Devils Tower in the state of Wyoming. Not only is Devils Tower a stunning example of a laccolithic butte (a large hill formed by a projection up through the crust of the Earth that has a column like appearance with a relatively flat top), but the location also features prominently in the oral history of the Kiowa, Lakota, Arapaho, Cheyenne, and other Native American tribes.