1. On July 31, 1890, South Dakota was admitted as the 40th state in the United States. The territory had been seeking statehood for several years, and its admission was a major milestone for the region.

2. In 1943, the town of Hill City in the Black Hills experienced a devastating flood on July 31. Heavy rainfall caused rapid rises in the nearby creeks and rivers, leading to widespread damage to homes, businesses, and infrastructure throughout the area.

3. On July 31, 1976, the iconic Mount Rushmore National Memorial hosted its first evening lighting ceremony, which has since become a popular attraction for visitors to the area. The ceremony features patriotic music and the illumination of the massive sculpture in the dark, creating a stunning visual display.

4. In 1983, the state of South Dakota passed a law officially designating July 31 as "Ethnic Awareness Day," to celebrate the state's diverse cultural heritage. The day is meant to promote understanding and appreciation of the different ethnic groups that call South Dakota home.

5. July 31 is also National Cowboy Day, honoring the iconic figures of the American West. South Dakota has a rich cowboy and ranching history, and the state celebrates the day with rodeos, chuckwagon cookouts, and other western-themed events.