1. In 1866, the first steam-powered sawmill in the Dakota Territory was established near the present-day location of Wall, South Dakota. This sawmill helped advance the logging industry in the region and contributed to the growth of South Dakota's economy.

2. In 1881, the Black Hills Mining Association was formed in Lead, South Dakota. This association played a significant role in the mining industry of the Black Hills and served as a voice for miners' rights and interests.

3. In 1937, the Mount Rushmore National Memorial was officially dedicated by President Franklin D. Roosevelt. The monument, located in the Black Hills, features the faces of four U.S. presidents sculpted into the mountainside. It has become one of South Dakota's most famous and popular attractions.

4. In 1953, the first South Dakota Public Broadcasting station (SDPB) went on the air in Vermillion, South Dakota. Since then, SDPB has grown to include multiple television and radio stations that serve South Dakota and surrounding states.

5. In 1976, the Black Hills Flood devastated Rapid City, South Dakota. The flood, caused by heavy rainfall and rapid snow melt, killed 238 people and caused millions of dollars in damage. It remains one of the deadliest natural disasters in South Dakota's history.