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zipcodes.pro — STATE/SD/COUNTY/LAKE

Lake County, SD ZIP codes

There are 7 ZIP codes in Lake County, SD, in 7 towns, from 57016 to 57076. The largest are 57042 (Madison), 57075 (Wentworth) and 57016 (Chester).

The county seat is Madison.

ZIP codes
7
Towns
7
County seat
Madison
County FIPS
46079
Population
10,972
Median household income
$76,808
Land area
563 sq mi

Lake County ZIP codes by town

Madison (county seat)
57042

Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.

Map of Lake County ZIP codes

57016570425705057054570575707557076

The ZIP codes of Lake County, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Lake County in numbers

About 10,972 people live in Lake County, in 4,716 households, the 16th most populous of South Dakota's 66 counties. The median household income is $76,808 a year, about the same as the South Dakota median of $75,081 (US: $80,734). The median owner-occupied home is valued at $247,600 (4% below the South Dakota median), and median gross rent is $947 a month. The median age is 43.8; 34.6% of adults 25 and over hold a bachelor's degree or higher (31.9% across South Dakota); the average commute takes 15 minutes.

Population10,972Lake10,972
Households4,716Lake4,716
Median age43.8Lake43.8South Dakota38.0US 38.9
Median household income$76,808Lake$76,808South Dakota$75,081US $80,734
Median home value$247,600Lake$247,600South Dakota$257,400US $332,700
Median gross rent$947Lake$947South Dakota$946US $1,413
Bachelor's degree or higher34.6%Lake34.6%South Dakota31.9%US 35.7%
Mean commute14.9 minLake14.9 minSouth Dakota17.8 minUS 26.4 min
Population density19 / sq miLake19 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates. Survey estimates carry margins of error, wider for small places. Sources and methods.

Largest towns in Lake County

Largest towns in Lake County
TownZIP codesPopulation
Madison 1 6,094
Ramona 1 538
Rutland 1 196
Chester 1 152
Wentworth 1 138
Nunda 1 40
Winfred 1 34

Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.

Neighbouring counties

Counties that share a ZIP code with Lake County.

Not sure you are in Lake County? What county am I in? answers from your location, near a county line included.

Every ZIP code in Lake County, with figures

ZIP codes in Lake County
ZIP City Type Population Median income Median home
57016 Chester , SD Standard 676 $95,815 $242,300
57042 Madison , SD Standard 7,756 $71,868 $228,200
57050 Nunda , SD Standard 176 $116,563 $262,500
57054 Ramona , SD Standard 703 $86,875 $97,100
57057 Rutland , SD Standard 196 $71,500 $266,700
57075 Wentworth , SD Standard 1,296 $106,763 $426,800
57076 Winfred , SD Standard 325 $118,281 $369,200

Cite this page

zipcodes.pro. “Lake County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/sd/county/lake

Underlying data is public domain or openly licensed — sources, vintages and licences.