US ZIP Code
57421

Amherst, SD

Marshall County  ·  South Dakota

● Active
👥 75 Population ↓ 3% since 2019
🎂 16.3 Median Age ↓ 51% since 2019
🎓 100.0% College Grads
▲ 158% above avg
📊 0.0% Unemployment
▼ 100% below avg
ZIP Code Details
ZIP Code57421
CityAmherst
StateSouth Dakota (SD)
CountyMarshall County
Area Code605
Elevation1,312 ft
Latitude45.755478
Longitude-97.907063
TimezoneChicago (DST)
FIPS46091
ZIP TypeStandard
StatusActive
People & Population (ACS 2023)
♂ Male 37.3% (28) Female 62.7% (47) ♀

Race & Ethnicity

White: 100%Race
White100.0%

Age Breakdown

5–17
61%
45–64
35%
65+
4%

Key Indicators

Median Age16.3 yrs ↓ 51% since 2019
Avg Household Size4.69
Below Poverty0.0% ▼ 100% below avg
College Grads100.0% ▲ 158% above avg
Unemployment0.0% ▼ 100% below avg
Bachelors2 (11.1%)
Graduate Degree16 (88.9%)

Education

Bachelors: 11.1%Graduate: 88.9%Edu
Bachelors11.1%
Graduate88.9%
Housing & Income

Housing Tenure

Owner: 100%Tenure
Owner100.0%

Home Value Distribution

$150k–200k
81%
$200k–300k
19%

Financials

Total Units24
Vacant Units8
Avg HH Size4.69

Income Distribution

$100k–150k
19%
$150k–200k
81%
Employment & Commute

How People Get to Work

Drove Alone
46%
Work From Home
54%

Commute Time

Over 45 min
100%
Housing Stock

Year Built

Before 1940
41%
1960s–1970s
9%
2000+
50%

Summary

Total Units24
Vacant8
Owner Occupied100.0%
Renter Occupied0.0%
Avg HH Size4.69
Frequently Asked Questions
ZIP code 57421 is in Amherst, SD, in Marshall County.
ZIP code 57421 is located in South Dakota (SD).
ZIP code 57421 is in Marshall County, SD.
ZIP 57421 observes the Chicago timezone. Daylight Saving Time is observed.
The estimated population of ZIP code 57421 is 75 people (ACS 2023).
Income data not available.
Home value data not available.
About ZIP Code 57421

ZIP code 57421 is located in Amherst, South Dakota, within Marshall County. With a population of 75, this is a sparsely populated ZIP code with a young community — the median age is 16.3 years.

The population of 57421 is primarily White (100.00%). Residents are highly educated — 100.0% hold a bachelor's degree or higher, which is more than double the national average.

A notably high share of workers — 54% — work from home, reflecting the professional makeup of the area. As in most parts of the country, driving alone is the dominant commute mode at 46%.

Overall, ZIP code 57421 in Amherst, SD is characterized as highly educated, a young community, and predominantly owner-occupied.