File:VermilionSD_ClayCountyCourthouse.jpg · Wikimedia Commons · See Wikimedia Commons
Clay County
Also known as Clay County, South Dakota, Clay County, SD
county in South Dakota, United States
Key facts
- Country
- United States
- State
- South Dakota
- Founded
- April 10, 1862
- Named after
- Henry Clay
- Seat
- Vermillion
- Largest city
- Vermillion
- Total
- 417.419 sq mi (1,081.11 km )
- Land
- 412.022 sq mi (1,067.13 km )
- Water
- 5.397 sq mi (13.98 km ) 1.3%
- Estimate 2025
- 15,031
- Density
- 37.451/sq mi (14.460/km )
- Time zone
- UTC−6 ( Central )
- Summer dst
~8 min read
Article
Clay County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 14,967, and was estimated to be 15,245 in 2024. The county seat is Vermillion, which is also home to the University of South Dakota. The county is named for Henry Clay, American statesman, US Senator from Kentucky, and United States Secretary of State in the 19th century. Clay County comprises the Vermillion, SD Micropolitan Statistical Area, which is also included in the Sioux City-Vermillion, Iowa-SD-Nebraska Combined Statistical Area.
History
Gallery (2)
On the map
2 mapped locations