ZIP code · Amherst · South Dakota · United States
ZIP code 57421 — Amherst
ZIP code 57421 serves Amherst, South Dakota.
- Postal code
- 57421Single source Value from one source, not cross-checked.
- City
- Amherst
- County
- Marshall
- State
- South Dakota
- Country
- United States
- Coordinates
- 45.7585, -97.9274 — precision precise (locality)
View on OpenStreetMap - Population
- 75 (ZCTA, ACS 5-year)
- Median age
- 16.3
Nearby localities
About this page
US ZIP codes have five digits. They are postal routing areas, not administrative boundaries: a ZIP can span more than one city or county, and the city shown is the primary USPS name for that code.
GeoNames · census-acs5. Data generated on 2026-08-21. Methodology · Report an error on this page