1. In 1889, South Dakota was admitted as the 40th state in the United States on May 7th.

2. The first rodeo in South Dakota was held in Belle Fourche on May 7, 1918. The event was organized by the American Legion and featured bronc and bull riding, calf roping, and steer wrestling.

3. On May 7, 1943, the United States Army Air Forces' 341st Bombardment Group conducted a training exercise in the Black Hills region of South Dakota. During the exercise, one of the aircraft, a B-17 Flying Fortress, crashed near Pactola Lake, killing all ten crew members on board.

4. South Dakota's first National Park, Wind Cave National Park, was established on May 7, 1903. The park is known for its complex underground cave system, which includes over 140 miles of mapped passages.

5. On May 7, 1964, the Wall Drug Store in Wall, South Dakota, erected its first billboard promoting free ice water. Over the next several decades, Wall Drug became a popular tourist attraction, known for its kitschy advertising campaigns and unique offerings such as a mechanical T-Rex and a giant jackalope statue.