1. The Rapid City Flood of 1972
September 27, 1972, marks one of the deadliest natural disasters in South Dakota history. Rapid City experienced a severe flash flood that killed 238 people and caused $165 million in damages.

2. Statehood Day
September 27, 1889, is the day South Dakota became an official state, joining the Union as the 40th state. Locals celebrate this day as Statehood Day, officially recognizing South Dakota's statehood.

3. Mount Rushmore is Completed
On September 27, 1941, the finishing touches were put on the Mount Rushmore National Memorial. Sculptor Gutzon Borglum and his team had been working on the project, which depicts the faces of four U.S. presidents, since 1927.

4. The Arrival of Lewis and Clark
On September 27, 1804, the famous explorers Meriwether Lewis and William Clark arrived in present-day South Dakota. Their expedition, which was commissioned by then-President Thomas Jefferson, sought to explore and map the newly acquired Louisiana Purchase territory.

5. The Turnaround of the Black Hills Central Railroad
On September 27, 1957, the Black Hills Central Railroad, a tourist railroad in South Dakota, was put back into operation after years of decline. The railroad, which runs through the scenic Black Hills region, has since become a popular tourist attraction in the state.