1. 1894: The Belle Fourche Irrigation District was established in western South Dakota, providing irrigation water to farmers and ranchers in the region. This helped spur agricultural development and economic growth in the area.

2. 1937: The iconic Mount Rushmore National Memorial was officially dedicated, after years of planning and construction. The massive sculpture features the faces of former presidents George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln, and has become a symbol of American patriotism and ingenuity.

3. 1960: Legendary basketball coach Don Meyer was born in Wayne, Nebraska. Meyer went on to coach at Northern State University in Aberdeen, South Dakota, where he became one of the winningest coaches in NCAA history. He also served as a mentor and inspiration to countless players and coaches throughout his career.

4. 1993: The Black Hills Flood of 1993 devastated communities throughout western South Dakota, causing more than $150 million in damage and claiming several lives. This tragic event spurred a massive recovery and rebuilding effort, as well as renewed emphasis on flood preparedness and prevention.

5. 2018: A team of researchers from South Dakota State University announced the discovery of a new species of dinosaur in Harding County, South Dakota. The new species, named Moros intrepidus, is thought to be a distant relative of the fearsome Tyrannosaurus rex, and lived during the Late Cretaceous period approximately 96 million years ago. The discovery highlights the rich paleontological history of the region, and underscores the ongoing importance of preserving and studying South Dakota's unique natural resources.