ZIP Codes of Hamlin County, SD

Population & People
Population & People
Total Population
6,477
Household Income
Household Income
Median Income
$90,821
Housing
Housing
Total Housing Units
2,872
Business & Economy
Business & Economy
Total Businesses
209
Employment
Employment
Employment Rate
70.39%
Education
Education
Bachelor's Degree+
26.30%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 6 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:6 ZIP Codes (6 Standard, 0 PO Box, 0 Unique) [See All]
Area Code:605
Timezone:Central (GMT -06:00)
Local Time:2:13:42 PM
Population:6,477 [See All]
FIPS:46057
Land Area:628 sq mi
Water Area:24 sq mi
Coordinates:44.6646, -97.1903
Quick Link:
https://www.zip-codes.com/county/sd-hamlin.asp
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South Dakota's #27 most populous county
6,477 residents across 6 ZIPs — #27 of 82 South Dakota counties.

Standout ZIPs in this County


Most Populous
Castlewood · 1,429 people
22.1% of county total
Highest Income
Hazel · $113,958 median
1.3× county average
Largest Land Area
Bryant · 127.5 sq mi
Spans the most ground
Fastest Growth
Lake Norden · 11.2% (10-yr)
1,165 → 1,295 residents
Most Educated
— no education data

Things worth knowing about Hamlin County


6,477 residents live across 6 ZIPs covering 628 sq mi, served by 6 distinct USPS-recognized cities.

Population moved from 5,934 to 6,477 from 2014 to 2024 — a +9.2% change. 4 ZIPs gained residents, 2 lost.

The county's wealthiest ZIP 57242 (Hazel, $113,958 median) and poorest ZIP 57221 (Bryant, $73,988) are 12.0 miles apart — a 1.5× income gap across local geography.

Median home values vary 2.4× across this county — from $123,000 in 57241 (Hayti) to $293,200 in 57248 (Lake Norden).

Density varies across the county — from 4 people/sq mi in 57242 (Hazel) to 16 in 57248 (Lake Norden).

Educational attainment ranges from 17.2% bachelor's+ in 57221 (Bryant) to 29.7% in 57234 (Estelline) — the breadth of educational profiles across the area.

Within South Dakota, this is the #27 most populous of 82 counties and ranks #10 for median household income with the #16 fastest decade growth .

Weighted by population, the typical household earns about $87,946 across the county — reflecting what a typical resident sees, not a simple ZIP average.

26.3% of adults age 25+ hold a bachelor's degree or higher (1,004 of 3,818 reporting).

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

Stories about Hamlin 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
628
square miles
Avg density
10.3
people per sq mi
Population
6,477
across 6 ZIPs
Bryant
127.5 sq mi
1,158 residents
Castlewood
126.1 sq mi
1,429 residents
Hayti
108.0 sq mi
936 residents

All ZIP Codes in Hamlin County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
57223CastlewoodStandard1,429$92,424126.17.4%
57234EstellineStandard1,339$82,358104.8-6.4%
57248Lake NordenStandard1,295$96,36479.611.2%
57221BryantStandard1,158$73,988127.562.6%
57241HaytiStandard936$85,833108.0-7.8%
57242HazelStandard320$113,95882.113.5%

Adjacent & Nearby Counties