1. On September 25, 1906, President Theodore Roosevelt designated the Devils Tower National Monument in Wyoming as the first U.S. National Monument. The iconic geological formation, located in the northeastern part of the state, is a sacred site to many Native American tribes and is known for its unique hexagonal columns.

2. In 1943, the University of Wyoming in Laramie was designated as a naval flight training center during World War II. The program trained hundreds of naval aviators, including future astronaut and U.S. Senator John Glenn.

3. On September 25, 1957, the second-largest coal mine disaster in Wyoming history occurred when an explosion at the Wilcox Coal Company mine in Hanna killed 21 miners. The tragedy led to improved safety regulations in the mining industry.

4. In 1969, the University of Wyoming's "Black 14" football team made national headlines when head coach Lloyd Eaton dismissed 14 black players from the team for seeking to wear black armbands in protest of their Mormon faith's ban on black priests. The incident sparked protests and calls for racial equality on campus.

5. On September 25, 1984, Wyoming native and former governor Nellie Tayloe Ross was honored with a commemorative stamp by the United States Postal Service. Ross was the first woman to serve as governor of a U.S. state, and her stamp was part of a series celebrating notable American women.