1. On June 11, 1910, the University of Oklahoma granted its first Ph.D. degree to Arthur Grant Evans for his thesis on "The Histology of the Pineal Organ of Selachians". This marked an important milestone in the university's academic history, as it signaled the institution's commitment to advanced research and scholarship.

2. On June 11, 1941, the Oklahoma City Zoo opened its gates to the public for the first time. The zoo was originally established in 1902 as a small collection of animals in a park, but it grew over the years and is now one of the state's most popular attractions, housing over 1,500 animals from over 500 species.

3. On June 11, 1963, President John F. Kennedy landed in Tulsa to give a speech at the dedication of the Ollie Marie Givens Hall. The hall, named after a prominent African American educator, was the first building in the state of Oklahoma to be financed by the Department of Housing and Urban Development's Low Rent Public Housing program.

4. On June 11, 2011, a devastating EF-5 tornado struck the city of Joplin, Missouri, killing over 150 people and injuring hundreds more. The storm had a strong impact on the neighboring state of Oklahoma, which sent many emergency response teams to help with the relief efforts.

5. On June 11, 2018, Oklahoma voted in favor of legalizing medical marijuana through a ballot initiative. This marked a significant step forward for the state's healthcare system and its efforts to address the opioid epidemic, as medical marijuana has been shown to be an effective pain management tool. The law went into effect on July 26, 2018, and as of 2021, medical marijuana is legal in 36 states and D.C.