1. The Oklahoma Territory was Established on May 3, 1890
On May 3, 1890, the Oklahoma Territory was officially established by the United States Congress. This area included what is now the state of Oklahoma, as well as parts of Kansas, Colorado, New Mexico, and Texas.

2. May 3, 1999, Tornado Outbreak
On May 3, 1999, a massive tornado outbreak occurred across the central United States. The outbreak produced 71 tornadoes in 21 states, with the most destructive tornado hitting Oklahoma City. This F-5 tornado killed 36 people and caused over $1 billion in damage.

3. Oklahoma Statehood Day is Celebrated on May 3
Oklahoma Statehood Day is celebrated on May 3 each year to commemorate the 1907 admission of Oklahoma to the United States as the 46th state.

4. Oklahoma City Thunder Reached the Western Conference Finals on May 3, 2011
On May 3, 2011, the Oklahoma City Thunder defeated the Memphis Grizzlies in a series-clinching game to advance to the Western Conference Finals for the first time in franchise history. The Thunder would go on to lose in the finals to the Dallas Mavericks.

5. Oklahoma Governor Mary Fallin Signed Bill Allowing the Use of Nitrogen Gas in Executions on May 3, 2018
On May 3, 2018, Oklahoma Governor Mary Fallin signed a bill allowing the state to use nitrogen gas as an alternative method of execution for death row inmates. This came after a series of botched lethal injection executions in the state sparked controversy and legal challenges. However, as of 2021, no executions using nitrogen gas have taken place in Oklahoma.