1. The Land Run of 1889 occurred on April 22: On this day in Oklahoma history, thousands of people raced to claim land in the Unassigned Lands, an area in central Oklahoma that had been opened up for settlement by the U.S. government. Known as the Land Run of 1889, this event marked the beginning of Oklahoma's territorial period.

2. The Oklahoma City bombing occurred on April 22, 1995: One of the most tragic events in Oklahoma history, the bombing of the Alfred P. Murrah Federal Building in Oklahoma City, took place on April 22, 1995. The attack, carried out by domestic terrorists Timothy McVeigh and Terry Nichols, killed 168 people and injured hundreds more.

3. The Oklahoma State Capitol was dedicated on April 22, 1917: After years of construction, the Oklahoma State Capitol was officially dedicated on April 22, 1917. The building, which features a dome modeled after the one on the U.S. Capitol, remains one of the most recognizable landmarks in Oklahoma City.

4. The Oklahoma City Thunder played their first playoff game on April 22, 2010: The Oklahoma City Thunder, the state's NBA team, played their first playoff game on April 22, 2010, against the Los Angeles Lakers. Although they ultimately lost the game, the Thunder would go on to become one of the most successful franchises in the league in the years that followed.

5. The first tornado warning was issued on April 22, 1952: On April 22, 1952, the National Weather Service issued the first tornado warning in U.S. history. The warning was issued for the town of Tinker Air Force Base, which is located in Oklahoma City, and gave residents 20 minutes to seek shelter before the storm hit. This landmark event helped to establish the modern system of warning the public about severe weather.