ZIP Codes of Bennett County, SD

Population & People
Population & People
Total Population
3,301
Household Income
Household Income
Median Income
$36,298
Housing
Housing
Total Housing Units
1,111
Business & Economy
Business & Economy
Total Businesses
59
Employment
Employment
Employment Rate
45.10%
Education
Education
Bachelor's Degree+
18.76%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 3 ZIPs in this county.
Data Last Updated: July 1, 2026
ZIP Codes:3 ZIP Codes (3 Standard, 0 PO Box, 0 Unique) [See All]
Area Code:605
Timezone:Mountain (GMT -07:00)
Local Time:11:55:00 PM
Population:3,301 [See All]
FIPS:46007
Land Area:1,144 sq mi
Water Area:6 sq mi
Coordinates:43.2319, -101.6334
Quick Link:
https://www.zip-codes.com/county/sd-bennett.asp
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South Dakota's #43 most populous county
3,301 residents across 3 ZIPs — #43 of 82 South Dakota counties.

Standout ZIPs in this County


Most Populous
Martin · 2,084 people
63.1% of county total
Highest Income
Martin · $70,096 median
1.9× county average
Largest Land Area
Martin · 983.2 sq mi
Spans the most ground
Fastest Growth
Allen · 8.5% (10-yr)
1,054 → 1,144 residents
Most Educated
Martin · 25.6% bachelor's+
305 of 1,193 adults 25+

Things worth knowing about Bennett County


3,301 residents live across 3 ZIPs covering 1,144 sq mi, served by 3 distinct USPS-recognized cities.

Population moved from 3,189 to 3,301 from 2014 to 2024 — a +3.5% change. 2 ZIPs gained residents, 1 lost.

The county's wealthiest ZIP 57551 (Martin, $70,096 median) and poorest ZIP 57574 (Tuthill, $2,499) are 8.2 miles apart — a 28.0× income gap across local geography.

Median home values vary 2.3× across this county — from $111,600 in 57714 (Allen) to $261,900 in 57574 (Tuthill).

Density varies 23× across the county — from 1 people/sq mi in 57574 (Tuthill) to 18 in 57714 (Allen).

Educational attainment ranges from 16.4% bachelor's+ in 57574 (Tuthill) to 25.6% in 57551 (Martin) — the breadth of educational profiles across the area.

Within South Dakota, this is the #43 most populous of 82 counties and ranks #82 for median household income .

Weighted by population, the typical household earns about $67,808 across the county — reflecting what a typical resident sees, not a simple ZIP average.

18.8% of adults age 25+ hold a bachelor's degree or higher (317 of 1,690 reporting).

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

Stories about Bennett 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
1,144
square miles
Avg density
2.9
people per sq mi
Population
3,301
across 3 ZIPs
Martin
983.2 sq mi
2,084 residents
Tuthill
95.8 sq mi
73 residents
Allen
65.3 sq mi
1,144 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.

Martin

All ZIP Codes in Bennett County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
57551MartinStandard2,084$70,096983.22.0%
57714AllenStandard1,14465.38.5%
57574TuthillStandard73$2,49995.8-20.7%

Adjacent & Nearby Counties