1. On October 17, 1866, the United States Army established Fort Phil Kearny in present-day Wyoming. The fort was built to protect travelers along the Bozeman Trail and to provide support for prospectors heading to Montana's gold fields.

2. In 1904, the University of Wyoming was officially opened on October 17. The first students enrolled in the university's College of Liberal Arts, which offered courses in languages, literature, history, and science.

3. On October 17, 1936, the Medicine Bow National Forest was established in southern Wyoming. The forest covers over 1 million acres and is known for its diverse landscapes, including alpine meadows, dense forests, and high desert plains.

4. Wyoming's first commercial oil well was completed on October 17, 1889, near the town of Pavillion. The discovery of oil in Wyoming helped to spur economic growth and development in the state.

5. In 1966, October 17 was designated as a holiday in Wyoming to commemorate the state's admission to the Union on July 10, 1890. The holiday, known as Wyoming Day, is celebrated annually with parades, festivals, and other events throughout the state.