1. The University of South Dakota was founded on October 7, 1862, becoming the first public university in the Dakota Territory. It began as a small liberal arts college and has since expanded to offer a wide range of programs in various fields.

2. On October 7, 1873, a devastating fire swept through the city of Deadwood, destroying much of the town. The fire began in a lodge hall and spread quickly, fueled by high winds and dry weather. Despite the efforts of firefighters, the fire raged for hours and left many people homeless.

3. In 1936, the Mount Rushmore National Memorial was formally dedicated on October 7. The iconic sculpture features the faces of four American presidents carved into the granite mountain: George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt. It remains one of South Dakota's most popular tourist attractions.

4. On October 7, 1967, the Rapid City flood caused widespread devastation across the area. Heavy rainfall over several days caused several dams to fail, unleashing a wall of water that destroyed hundreds of homes and businesses. The flood resulted in over $160 million in damages and claimed over 200 lives.

5. October 7 is also celebrated as Native American Day in South Dakota, a holiday that recognizes the contributions and culture of the state's indigenous people. The holiday was first established in 1990 and is now observed on the second Monday in October. It includes various events and activities across the state, such as powwows, traditional dances, and native food tastings.