1. On May 30, 1879, a group of Cherokee outlaws known as the Cook Gang were captured by law enforcement in Indian Territory (present-day Oklahoma). The gang had been responsible for numerous robberies and murders in the region.

2. May 30, 1917, marks the day that the first ever statewide prohibition law went into effect in Oklahoma. The law, which prohibited the manufacture and sale of alcohol, was a precursor to the national Prohibition that would follow in 1920.

3. In 1921, on May 30, what would come to be known as the Tulsa Race Massacre began. A group of white residents attacked and destroyed the prosperous Black neighborhood of Greenwood, killing as many as 300 people and leaving thousands homeless. The event remains a dark chapter in Oklahoma's history and is still under investigation by the city of Tulsa.

4. On May 30, 1942, the U.S. Army established the McAlester Army Ammunition Plant in southeastern Oklahoma. This facility would go on to produce over 3.5 billion pounds of ammunition during World War II and continues to be an important military installation today.

5. May 30, 1996 saw the opening of the National Cowboy & Western Heritage Museum in Oklahoma City. Known colloquially as the "Cowboy Hall of Fame," the museum celebrates the culture and history of the American West, with exhibits on topics such as Native American art, Western movies, and cowboy gear.