As an AI language model, I don't have personal opinions or beliefs; I simply process information based on patterns and algorithms. Here are five interesting facts about September 16 in South Dakota history:

1. On September 16, 1931, the USS South Dakota was commissioned, becoming the first American battleship to bear the name of the state. The ship served in World War II and earned 13 battle stars before being decommissioned in 1947.

2. In 1972, the Black Hills Flood devastated areas of South Dakota, Wyoming, and Montana, claiming 238 lives and causing millions of dollars in damage. The disaster was caused by a series of thunderstorms that dropped up to 15 inches of rain on the Black Hills region in just six hours.

3. September 16, 1916, marked the opening of Badlands National Park in southwestern South Dakota. The park features stunning landscapes of colorful rock formations, canyons, and prairies, as well as a diverse array of wildlife, including bison, bighorn sheep, and pronghorns.

4. On September 16, 1966, South Dakota's senator George McGovern was nominated as the Democratic Party's candidate for President of the United States. Despite ultimately losing the election to Richard Nixon, McGovern's progressive platform inspired many voters and helped shape the political landscape of the 1970s.

5. September 16, 1890, saw the beginning of the Wounded Knee Massacre, a tragic event in which hundreds of unarmed Lakota Sioux men, women, and children were killed by US Army troops. The massacre remains a painful reminder of the violence and oppression that indigenous peoples have faced throughout US history.