Union County, South Dakota ZIP Codes

4 ZIP Codes

Zip Code
City
Population ↓
57049North Sioux City7,962
57025Elk Point3,120
57038Jefferson1,796
57001Alcester1,540

Overview of ZIP Codes in Union County

ZCTAs are geographic areas created by the US Census Bureau to approximate the delivery areas of ZIP Codes for statistical analysis. While ZCTAs use the same five-digit codes as ZIP Codes, they represent defined geographic areas that may not exactly match the mail delivery routes of ZIP Codes.
4
ZIP Codes

The data shown reflect ZCTAs from the US Census. As of 2025, there are 4 ZCTAs in Union County, South Dakota (US Census).

Sources

  1. US Census: 2025 Gazetteer Files
  2. US Census: ZIP Code Tabulation Areas (ZCTAs)

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