Union County is the southernmost county in the U.S. state of South Dakota. As of the 2020 census, the population was 16,811, making it the 13th most populous county in South Dakota. Its county seat has been Elk Point since April 30, 1865. Originally named Cole County, its name was changed to Union on January 7, 1864, because of Civil War sentiment.
AdSee condos and townhomes for sale, connect with local experts and schedule the tour today. Realtor.com® puts the best tools in your hands. Find the perfect condos, townhomes & more
Home Buying Tips · Draw your own search area · Affordability Calculator