Here are 5 interesting facts about April 20 in Oklahoma history:

1. On April 20, 1889, the first land run in Oklahoma took place. Over 50,000 people raced to grab a piece of land in the Unassigned Lands, which later became Oklahoma City.

2. On April 20, 1914, the Ludlow Massacre occurred in Colorado, which was significant for Oklahoma due to the role two Oklahomans played in organizing and leading the striking miners who were attacked by the Colorado National Guard.

3. On April 20, 1936, Oklahoma City began construction on the Civic Center Music Hall, which now serves as a popular venue for performing arts in the city.

4. On April 20, 2010, the Deepwater Horizon oil rig explosion occurred, which resulted in the largest oil spill in U.S. history. While the spill did not occur in Oklahoma, the state's oil and gas industry was impacted by changes in regulations and increased scrutiny.

5. On April 20, 2015, the Oklahoma state legislature passed a bill to legalize the use of cannabidiol (CBD) oil for children with epilepsy. This marked a significant shift in the state's stance on medical marijuana and paved the way for future reforms.