ZIP Codes of Corson County, SD

Population & People
Population & People
Total Population
3,285
Household Income
Household Income
Median Income
$59,710
Housing
Housing
Total Housing Units
1,102
Business & Economy
Business & Economy
Total Businesses
25
Employment
Employment
Employment Rate
43.08%
Education
Education
Bachelor's Degree+
17.23%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 3 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:10 ZIP Codes (8 Standard, 2 PO Box, 0 Unique) [See All]
Area Code:701
Timezone:Central (GMT -06:00)
Local Time:2:13:41 PM
Population:3,285 [See All]
FIPS:38085
Land Area:1,863 sq mi
Water Area:34 sq mi
Coordinates:46.2704, -100.7348
Quick Link:
https://www.zip-codes.com/county/sd-corson.asp
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Notable population decline
Lost 16.8% of residents since 2014.
Among America's 25 youngest counties
Median age 26.0 — #16 youngest nationwide.
South Dakota's most renter-heavy county
52.4% of homes are renter-occupied.
Notable income spread
Median income ranges $23,000 to $88,125 across ZIPs — a 3.8× gap.
Striking education divide
Bachelor's share spans 14.4% to 45.9% — a 32-point gap.

Standout ZIPs in this County


Most Populous
Mc Laughlin · 1,969 people
52.1% of county total
Highest Income
Keldron · $88,125 median
1.5× county average
Largest Land Area
Mc Laughlin · 637.1 sq mi
Spans the most ground
Fastest Growth
Mc Laughlin · -7.4% (10-yr)
2,126 → 1,969 residents
Most Educated
Mc Laughlin · 19.5% bachelor's+
208 of 1,064 adults 25+

Things worth knowing about Corson County


3,776 residents live across 10 ZIPs covering 1,863 sq mi, served by 10 distinct USPS-recognized cities.

Population moved from 4,063 to 3,760 from 2014 to 2024 — a -7.5% change. 4 ZIPs gained residents, 5 lost.

The county's wealthiest ZIP 57634 (Keldron, $88,125 median) and poorest ZIP 57639 (Little Eagle, $21,250) are 52.2 miles apart — a 4.1× income gap across local geography.

Median home values vary 2.9× across this county — from $52,100 in 57645 (Morristown) to $151,600 in 57634 (Keldron).

Density varies 218× across the county — from 1 people/sq mi in 57634 (Keldron) to 139 in 57639 (Little Eagle).

Educational attainment ranges from 8.9% bachelor's+ in 57621 (Bullhead) to 45.9% in 57634 (Keldron) — the breadth of educational profiles across the area.

Within South Dakota, this is the #31 most populous of 64 counties and ranks #58 for median household income .

Weighted by population, the typical household earns about $53,233 across the county — reflecting what a typical resident sees, not a simple ZIP average.

19.2% of adults age 25+ hold a bachelor's degree or higher (396 of 2,066 reporting).

8 Standard delivery, 2 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Corson County


Two counties in one

Median household income spans 4.1× between the wealthiest and poorest ZIPs — a sign of significant intra-county inequality.

Wealthiest ZIP
Keldron
Median income: $88,125
Population: 131
Bachelor's+: 45.9%
vs
Poorest ZIP (pop >= 500)
Little Eagle
Median income: $21,250
Population: 290
Bachelor's+: 0.0%
For every $1 of household income in 57639, the typical household in 57634 earns $4.15.

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
1,863
square miles
Avg density
2.0
people per sq mi
Population
3,776
across 10 ZIPs
Mc Laughlin
637.1 sq mi
1,969 residents
Trail City
310.5 sq mi
247 residents
Mc Intosh
240.0 sq mi
215 residents

Population decline

Corson County lost 16.8% of residents between 2014 and 2024.

All ZIP Codes in Corson County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
57642Mc LaughlinStandard1,969$58,750637.1-7.4%
57658WakpalaStandard319$23,000118.710.8%
57621BullheadPO Box294$32,58912.8-23.4%
57639Little EaglePO Box290$21,2502.1-17.4%
57657Trail CityStandard247310.511.8%
57641Mc IntoshStandard215$83,750240.0-26.6%
57645MorristownStandard184$56,667158.2-8.9%
57634KeldronStandard131$88,125205.98.3%
57660Cross StateStandard111$67,292160.744.2%
57659WalkerStandard16$103,33316.9

Adjacent & Nearby Counties