South Dakota census data shows younger populations on reservations and near universities

Some South Dakota counties are getting younger while others continue to age, according to South Dakota News Watch. U.S. Census data shows the age group 15-19 is now the largest in the state, making up 6.9 percent of the population in 2024. Jared McEntaffer, CEO of the Dakota Institute, said higher birth rates in reservation counties are a major factor.

In Buffalo County, home to the Crow Creek Reservation, the most common age group shifted from 25-34 in 2010 to 10-14 in 2024.The 10-14 age group now represents 10.9 percent of the population. In Oglala Lakota County, part of the Pine Ridge Reservation, children ages 10-14 make up 10.8 percent of the population.

College towns also drive the trend toward a younger population. Clay County, home to the University of South Dakota, has 22.3 percent of its population in the 20-24 age group, among the youngest averages nationwide. Meanwhile, 17.3 percent of the state’s residents are 65 or older, according to South Dakota News Watch.