ZIP Codes of Walworth County, SD

Population & People
Population & People
Total Population
5,347
Household Income
Household Income
Median Income
$55,716
Housing
Housing
Total Housing Units
2,989
Business & Economy
Business & Economy
Total Businesses
204
Employment
Employment
Employment Rate
58.19%
Education
Education
Bachelor's Degree+
28.77%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 5 ZIPs in this county.
Data Last Updated: July 1, 2026
ZIP Codes:5 ZIP Codes (4 Standard, 1 PO Box, 0 Unique) [See All]
Area Code:605
Timezone:Central (GMT -06:00)
Local Time:11:55:04 PM
Population:5,347 [See All]
FIPS:46129
Land Area:822 sq mi
Water Area:90 sq mi
Coordinates:45.4649, -100.1463
Quick Link:
https://www.zip-codes.com/county/sd-walworth.asp
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South Dakota's #37 most populous county
5,347 residents across 5 ZIPs — #37 of 82 South Dakota counties.

Standout ZIPs in this County


Most Populous
Mobridge · 3,422 people
64.0% of county total
Highest Income
Mobridge · $66,003 median
1.2× county average
Largest Land Area
Selby · 287.2 sq mi
Spans the most ground
Fastest Growth
Selby · 1.8% (10-yr)
1,144 → 1,165 residents
Most Educated
Mobridge · 32.8% bachelor's+
833 of 2,540 adults 25+

Things worth knowing about Walworth County


5,347 residents live across 5 ZIPs covering 822 sq mi, served by 5 distinct USPS-recognized cities.

Population moved from 5,665 to 5,347 from 2014 to 2024 — a -5.6% change. 3 ZIPs gained residents, 2 lost.

The county's wealthiest ZIP 57601 (Mobridge, $66,003 median) and poorest ZIP 57420 (Akaska, $40,469) are 18.2 miles apart — a 1.6× income gap across local geography.

Median home values vary 2.1× across this county — from $79,000 in 57420 (Akaska) to $162,500 in 57631 (Glenham).

Density varies 37× across the county — from 1 people/sq mi in 57452 (Java) to 23 in 57601 (Mobridge).

Educational attainment ranges from 13.3% bachelor's+ in 57452 (Java) to 36.9% in 57420 (Akaska) — the breadth of educational profiles across the area.

Within South Dakota, this is the #37 most populous of 82 counties and ranks #76 for median household income .

Weighted by population, the typical household earns about $62,885 across the county — reflecting what a typical resident sees, not a simple ZIP average.

28.8% of adults age 25+ hold a bachelor's degree or higher (1,113 of 3,868 reporting).

4 Standard delivery, 1 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Walworth County


Big & sparse

A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.

Total area
822
square miles
Avg density
6.5
people per sq mi
Population
5,347
across 5 ZIPs
Selby
287.2 sq mi
1,165 residents
Java
221.4 sq mi
136 residents
Mobridge
150.8 sq mi
3,422 residents

Single-ZIP anchor

One ZIP holds the majority of this county's population — a sign of a county built around a single city or town.

Mobridge

Population decline

Walworth County lost 5.6% of residents between 2014 and 2024. ZIPs that shed the largest share:

Mobridge
-11.4%
3,864 → 3,422 residents

All ZIP Codes in Walworth County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
57601MobridgeStandard3,422$66,003150.8-11.4%
57472SelbyStandard1,165$61,708287.21.8%
57631GlenhamStandard364$56,827135.321.3%
57420AkaskaPO Box260$40,46927.7326.2%
57452JavaStandard136$53,571221.4-54.1%

Adjacent & Nearby Counties