1. On December 14, 1890, the Wounded Knee Massacre occurred in South Dakota. US troops opened fire on an encampment of Sioux Native Americans, killing over 250 men, women, and children.

2. On December 14, 1915, the State of South Dakota officially designated the black hills spruce as the state tree. This coniferous tree is native to the Black Hills region of South Dakota.

3. On December 14, 1929, South Dakota became the first state in the US to require all cars registering in the state to have license plates.

4. On December 14, 1949, a fire broke out in the state capitol building in Pierre, South Dakota. The fire destroyed many of the building's interior furnishings and caused significant damage.

5. On December 14, 2010, the Sanford Underground Research Facility in Lead, South Dakota was officially dedicated. The facility, located in the former Homestake gold mine, is now one of the deepest underground research facilities in the world, and is used for a variety of scientific experiments and studies.