1. On May 31, 1879, construction began on the iconic Old Faithful Inn in Yellowstone National Park. The inn was designed to be a grand structure that would welcome visitors to the park and today it still serves as one of the most popular lodging options in Yellowstone.

2. In 1911, Wyoming Governor Joseph M. Carey signed a bill granting women in Wyoming full suffrage, making it the first state in the United States to grant women the right to vote. May 31 has since been designated as Wyoming Women's Suffrage Day.

3. The Cheyenne Frontier Days rodeo, one of the largest and most famous rodeos in the world, began on May 31, 1897. The event draws thousands of visitors to Wyoming every year to watch bull riding, barrel racing, and other rodeo competitions.

4. On May 31, 1950, the first nuclear weapon test was conducted at the Nevada Test Site, located just over the border from Wyoming. The test was part of a series of experiments conducted by the US government to assess the impact of nuclear weapons on the environment and on humans.

5. In 1922, the town of Lusk, Wyoming was hit by a devastating tornado that destroyed much of the downtown area and left many residents without homes or businesses. The tornado, which struck on May 31, was one of the most destructive in Wyoming history and serves as a reminder of the power of nature.