September 24, 2007 - Devil's Tower National Monument
On September 24, 1906, President Theodore Roosevelt designated Devil's Tower as the first National Monument. Rising 1267 feet above the Belle Fourche River in eastern Wyoming, over 20 American Indian tribes consider Devil's Tower a sacred place.
The establishment of the National Monument stemmed from a law passed that same year called the Antiquities Act of 1906. Passed on June 8th, the law authorized the President of the United States "to declare by public proclamation historic landmarks, historic and prehistoric structures, and other objects of historic or scientific interest that are situated upon the lands owned or controlled by the Government of the United States to be national monuments...."
Source: National Park Service