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Where am ILOCATED

Union County, South Dakota

Union County, South Dakota, has 17,402 residents (July 2025 estimate). Its county seat is Elk Point. It uses Central Time and covers 461 sq mi (1,193 km²) of land.

Sioux FallsRapid CityAberdeen
Union County in South Dakota
Plymouth CountyClay CountyDakota DunesNorth Sioux CityElk PointAlcester
Union County and its neighbors (simplified outlines). Open in OpenStreetMap ↗
Resident population, July 2025
17,402
Land area
461 sq mi (1,193 km²)
County seat or government
Elk Point
Time zone
Central TimeUTC-06:00 in January; UTC-05:00 in July
Median household income
$89,636 ± $5,949
Median home value
$301,100 ± $18,340
Median rent, with utilities
$1,069 ± $63
Homes lived in by their owners
73.1% ± 2.9 points
County type
County
Metro or micro area
Sioux City, IA-NE-SD metro areaCentral county
Water area
6.37 sq mi (16.5 km²)
State
South Dakota
County code (FIPS)
46127
Coordinates (central point)
42.831106, -96.650829
Open this point in the location finder

These coordinates mark a central point for the area, not a street address. Income, home value, rent and homes lived in by their owners: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, ± margin at 90% confidence; checked on October 13, 2026.

Time zones in Union County

Time zoneLocal time and UTC offsetNext clock change
Central TimeAmerica/ChicagoUTC-06:00 in January; UTC-05:00 in July. Enable JavaScript for the live clock.Enable JavaScript for upcoming changes.

Near a time-zone line, check where you are with the time-zone finder. Your phone’s setting can differ.

ZIP Code areas, largest first

  1. 570497,962 people
  2. 570043,834 people
  3. 510233,473 people
  4. 570253,120 people
  5. 510012,342 people
  6. 570381,796 people
  7. 570011,540 people
  8. 57010755 people
  9. 57034661 people

9 ZIP Code areas overlap Union County. People counts are 2020–2024 estimates for each whole ZIP area. Mailing ZIPs can differ; check an address with USPS ZIP Code Lookup.

Official county information

We don’t have a website for this county yet. The US government’s local-office directory ↗ lists its offices. A geographic lookup cannot determine eligibility, tax liability or a court obligation.

Townships in Union County, largest first

  1. Big Sioux Township4,917 people
  2. Jefferson Township1,088 people
  3. Virginia Township315 people
  4. Spink Township270 people
  5. Brule Township254 people
  6. Big Springs Township237 people
  7. Civil Bend Township191 people
  8. Prairie Township155 people
  9. Alcester Township142 people
  10. Emmet Township140 people
  11. Sioux Valley Township112 people
  12. Elk Point Township91 people

People counts are American Community Survey 2020–2024 5-year estimates. All townships in South Dakota, by county

School districts in Union County, largest first

  1. Vermillion School District 13-113,340 people
  2. Dakota Valley School District 61-88,312 people
  3. Elk Point-Jefferson School District 61-74,690 people
  4. Beresford School District 61-24,034 people
  5. Alcester-Hudson School District 61-12,458 people

Districts with land in the county; a district can cross county lines. People counts are American Community Survey 2020–2024 5-year estimates. A district boundary doesn’t decide which school a student attends.

Cities, towns and communities, largest first

These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.

  1. Dakota Dunes, South Dakota (CDP)3,936 people
  2. North Sioux City, South Dakota (city)3,045 people
  3. Elk Point, South Dakota (city)2,537 people
  4. Beresford, South Dakota (city)2,360 people
  5. Alcester, South Dakota (city)989 people
  6. Jefferson, South Dakota (city)554 people
  7. Richland, South Dakota (CDP)107 people

Bordering areas, nearest first

Distances are straight lines between map points.

  1. Clay County, South Dakota18 mi west
  2. Plymouth County, Iowa23 mi east
  3. Dixon County, Nebraska26 mi southwest
  4. Sioux County, Iowa30 mi northeast
  5. Dakota County, Nebraska31 mi south
  6. Lincoln County, South Dakota31 mi north
  7. Woodbury County, Iowa43 mi southeast

Before using this answer on a form

Use a precise point for address-level questions. A device accuracy circle can cross a boundary; confirm tax, voting or jury details with the responsible office.

Find the county where you are now, check its ZIP area, or check the time zone where you are.

See this county on Census.gov ↗

Areas that only touch the edge

These areas meet the boundary only along a sliver. Most addresses here are not in them; for an address near the line, check with the county.