1. Construction of the Buffalo Bill Dam in Wyoming began on July 31, 1905. The dam was completed in 1910 and created the famous Buffalo Bill Reservoir, which is still used for irrigation today.

2. On July 31, 1868, Fort Laramie was officially declared a peace negotiation site between the U.S. government and various Native American tribes. The negotiations eventually led to the Treaty of Fort Laramie, which attempted to establish peace and land rights for the tribes in the region.

3. In 1985, Yellowstone National Park recorded its highest-ever recorded temperature of 99 degrees Fahrenheit on July 31.

4. On July 31, 1923, the town of Encampment in southern Wyoming experienced a damaging tornado, which completely destroyed several buildings and killed two people.

5. Wyoming became the first state in the U.S. to grant women the right to vote on December 10, 1869, but a historic vote took place on July 31, 1870, when Wyoming held its first ever general election with women voting alongside men. This was a huge milestone for women's suffrage in the United States.