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Zip Code 57421 — Amherst, SD

57421 is a ZIP Code associated with Amherst, SD, located within Marshall. The postal region supports an estimated population of 75 residents across Data Pending housing units, with a population density of 0.9 people per square mile.
WorldPlaceData database updated: October 2026

📍 View location on OpenStreetMap (45.750450, -97.906180)

Data MetricLocal Statistic
Postal / Zip Code57421
Primary CityAmherst
State / ProvinceSD
CountyMarshall
Total Population75
Median Household IncomeData Pending
Total Housing UnitsData Pending
Population Density0.9 people/sq mi
TimezoneAmerica/Chicago

How 57421 Compares

MetricZIP 57421Marshall CountySD State Average
Population754,261906,188
Median IncomeData PendingN/AN/A
Population Density0.9 /sq mi----

Nearby ZIP Codes

ZIP CodeCityDistancePopulationMedian Income
Zip 57432Claremont7.3 mi507N/A
Zip 57430Britton10.2 mi1,828N/A
Zip 57454Langford11.6 mi732N/A
Zip 57449Houghton13.1 mi357N/A
Zip 57446Hecla14.4 mi223N/A

Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →