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.

Union County is part of the Sioux City metropolitan area. The Progressive Farmer rated Union County second in the "2006 Best Place to Live Survey" in the U.S., because "its schools are good, its towns neat and its people friendly".

History

Founded on April 10, 1862, as Cole County, it was renamed Union County on January 7, 1864, when its boundaries were changed to encompass land previously part of neighboring Lincoln County. The county seat was moved from Richland to Elk Point on April 30, 1865.

Geography

Union County lies on the southeast corner of South Dakota. Its east boundary line abuts the west boundary line of the State of Iowa (across the Big Sioux River), and its south/southwest boundary line abuts the north boundary line of the State of Nebraska (across the Missouri River). The Brule Creek flows southeasterly across the central part of the county, emptying into the Big Sioux. The county terrain consists of rolling hills, devoted to agriculture except around built-up areas. The terrain slopes to the south and east; its highest point is near its northwest corner, at ASL. The county has a total area of , of which is land and (1.4%) is water. It is the fifth-smallest county in South Dakota by area.

Major highways

  • 20px Interstate 29
  • 20px South Dakota Highway 11
  • 20px South Dakota Highway 19
  • 20px South Dakota Highway 46
  • 20px South Dakota Highway 48
  • 20px South Dakota Highway 50
  • 23px South Dakota Highway 105

Adjacent counties

  • Lincoln County to the north
  • Sioux County, Iowa to the northeast
  • Plymouth County, Iowa to the east
  • Woodbury County, Iowa to the southeast
  • Dakota County, Nebraska to the south
  • Dixon County, Nebraska to the southwest
  • Clay County to the west

Protected areas

Source:

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|footnote=U.S. Decennial Census<br>1790–1960 1900–1990<br>1990–2000 2010–2020 The population density was .

There were 6,822 households in the county, of which 30.8% had children under the age of 18 living with them and 19.5% had a female householder with no spouse or partner present. About 26.9% of all households were made up of individuals and 12.1% had someone living alone who was 65 years of age or older.

  • Junction City
  • Morganfield

Townships

  • Alcester
  • Big Sioux
  • Big Springs
  • Brule
  • Civil Bend
  • Elk Point
  • Emmet
  • Jefferson
  • Prairie
  • Richland
  • Sioux Valley
  • Spink
  • Virginia

Unorganized territory

  • Richland

Politics

Union County voters were more politically centered in times past, but the county has selected the Republican Party candidate in every national election since 2000 (as of 2024).

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See also

  • National Register of Historic Places listings in Union County, South Dakota

References

  • Union County Historical Society website
  • 2nd Best Place to Live in 2006 from the Progressive Farmer website