1. In 1889, the Pine Ridge Reservation was officially established by an executive order signed by President Benjamin Harrison. The reservation covers nearly 3,500 square miles in southwestern South Dakota and is home to the Oglala Sioux Tribe.

2. In 1914, the town of Vivian in Lyman County experienced a 6.5 magnitude earthquake, the strongest ever recorded in the state. Despite causing significant damage to buildings and infrastructure, there were no reported fatalities.

3. On August 30, 1927, the sculptor Gutzon Borglum began work on Mount Rushmore in the Black Hills of South Dakota. Over the next fourteen years, Borglum and his team would carve the likenesses of George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln into the mountain.

4. In 1943, South Dakota native Joe Foss became the first Marine Corps pilot to be awarded the Medal of Honor in World War II. Foss shot down 26 enemy planes during his time in the Pacific theater and later served as the governor of South Dakota.

5. On this day in 1961, the first class of students began their studies at the University of South Dakota School of Medicine in Vermillion. The school has since become a leading institution for medical education and research in the Midwest.