1. On September 20, 1907, Oklahoma became the 46th state to join the United States of America. This followed decades of political and cultural evolution, including the Indian Removal Act, the creation of Indian Territory, and the Land Run of 1889, which opened up a vast swath of what would become Oklahoma for settlement.

2. September 20, 1970 saw the infamous "Black Sunday" dust storm roll across the Oklahoma Panhandle, dramatically underscoring the ecological damage caused by decades of intensive farming and the depletion of the region's topsoil.

3. The state's second largest city, Tulsa, can claim a couple significant September 20 dates in its history. In 1961, civil rights activist and Tulsa resident Clara Luper led a successful sit-in protest at a local Katz Drug Store's lunch counter, helping to catalyze the early movement for desegregation. In 2016, Tulsa's Gathering Place park officially opened, boasting over 60 acres of attractions and winning the widely recognized distinction of being named "Best New Attraction" by USA Today.

4. On September 20, 1911, Aloysius Larch-Miller became Oklahoma's first known aeronautical fatality when his makeshift glider crashed near Wynnewood. Larch-Miller, an early aviation enthusiast, had constructed the glider himself and launched it using a self-designed catapult system; unfortunately, despite his enthusiasm and ingenuity, Larch-Miller had little knowledge of aerodynamics or engineering, and paid the ultimate price.

5. September 20, 2006 saw a valiant but ultimately unsuccessful attempt to break the world record for largest gathering of Elvis impersonators, when 894 participants showed up at the Tulsa State Fair, just shy of the 1,087 required. The event was organized by Elvis-A-Rama, a nonprofit organization raising funds for charitable causes.