1. On June 3, 1876, a battle between the United States Army and the Sioux and Cheyenne tribes took place at the Battle of the Rosebud. Although the battle was inconclusive, it foreshadowed the infamous Battle of Little Bighorn, which occurred just nine days later.

2. In 1901, the South Dakota State Historical Society was founded on June 3. The society is responsible for collecting and preserving the state's history, and operates several museums and historic sites throughout South Dakota.

3. June 3, 1910, marked the opening of the first Carnegie Library in Sioux Falls. The library was funded by a grant from Andrew Carnegie, and was one of over 2,500 libraries built with his donations across the United States.

4. In 1934, the Custer State Park Buffalo Roundup was first held on June 3. The event, which still takes place annually, involves herding the park's buffalo population to a central location for health checks and relocation if necessary.

5. On June 3, 1987, the final section of Interstate 90 in South Dakota was dedicated near Rapid City. The 412-mile stretch of highway connects the eastern and western edges of the state, and is a major thoroughfare for both local and long-distance travelers.