National Oklahoma Day is observed annually on June 7, celebrating Oklahoma as the 46th state to join the United States. This unofficial holiday was established by National Day Calendar as part of its National State Days project, which aims to recognize the diverse cultures and histories of each state. The name "Oklahoma" derives from the Choctaw language, meaning "the Land of the Red People," and its official nickname is the Sooner State, referencing illegal settlers known as Sooners who entered the area before the Oklahoma Land Rush of 1889. The state has a rich history, having been home to various Indigenous peoples prior to European exploration, and it became a territory in the early 19th century, eventually achieving statehood in 1907. Celebrations may include educational events and activities that highlight Oklahoma's heritage and contributions to the nation.