1. On July 19, 1918, the famous outlaw Harry Tracy was killed by law enforcement officers in Jackson, Wyoming. Tracy had gone on a shooting spree after escaping from prison in Oregon, and his trail eventually led him to Wyoming. He was surrounded and killed by a posse near the roof of a building in downtown Jackson.

2. In 1864, on July 19th, the Battle of Platte Bridge Station occurred during Red Cloud's War. Soldiers at the bridge were attacked by Native American warriors, and some of the soldiers were killed or captured. The battle was a major engagement in the war, which ultimately led to a peace treaty between the United States and the Sioux Nation.

3. July 19, 1890, saw the creation of Wyoming Territory's first national park. Yellowstone National Park, located primarily in Wyoming but also in Montana and Idaho, was established by an act of Congress signed by President Benjamin Harrison. It was the first national park in the United States and is known for its geysers, hot springs, and other natural wonders.

4. On July 19, 1957, the United States Air Force installed the first intercontinental ballistic missile (ICBM) in Wyoming. The missile, which was capable of carrying a nuclear warhead, was located at F.E. Warren Air Force Base near Cheyenne. The ICBM program was a key part of the United States' nuclear arsenal during the Cold War.

5. In 1923, on July 19th, a massive forest fire began near Clark, Wyoming. The fire burned for several weeks and consumed over 100,000 acres of forest. It was one of the largest and most destructive forest fires in Wyoming history, and it drew firefighters and resources from across the region to help contain it. The cause of the fire is still unknown.