Yankton County

Also known as Yankton County, South Dakota, Yankton County, SD

county in South Dakota, United States

Key facts

Country: United States
State: South Dakota
Founded: April 10, 1862
Named after: Yankton Sioux
Seat: Yankton
Largest city: Yankton
Total: 532 sq mi (1,380 km )
Land: 521 sq mi (1,350 km )
Water: 11 sq mi (28 km ) 2.1%
Estimate 2025: 23,635
Density: 45.4/sq mi (17.5/km )
Time zone: UTC−6 ( Central )
Summer dst: UTC−5 ( CDT )

~8 min read

Article

Missouri River in winter downstream from Yankton, with Nebraska below and South Dakota above. This stretch of the river is part of the 59-mile reach of the Missouri National Recreational River.

Yankton County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 23,310, making it the 9th most populous county in South Dakota. Its county seat is Yankton. Yankton County comprises the Yankton, SD Micropolitan Statistical Area.