Lake County GIS Maps
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Lake County, South Dakota, has 11,059 residents and covers 562.9 square miles. The population declined 1.3% between the 2010 and 2020 census. More residents left than arrived over that decade. The FIPS code for Lake County is 46079.
Madison is the county's largest population center. Lake County also includes 7 zip codes, 6 public school districts and 37 municipalities. Those boundaries help explain why population, schools, and housing can look different from one part of the county to another. The map below shows how those county lines, zip codes, and school districts fit together, and the sections that follow use that same geography to show population, demographics, school enrollment and housing patterns in more detail.
Maps, GIS layers and sample data. Paid packages add full layers, analytics and database files.
Lake County Trends
- Population
- 11,059▾
- Median Home Value
- $231,000▴
- K-12 Enrollment
- 3,565▴
County analytics dashboards with historical trends & projections included in package downloads.
Free starter access previews county maps, lightweight GIS, and sample data. Paid packages unlock full GIS layers, analytics, and database files.
Lake County Maps
The maps below show a few of the county map styles included in our downloads. County packages include map exports in JPEG, PNG, SVG, PDF and GeoTIFF formats plus more than 20 GIS layers for mapping, research and analysis. Available layers include zip codes, area codes, subdivisions, school districts, political boundaries, roads, water features, points of interest and more.
County packages also include historical county demographics, business intelligence, analytical dashboards, AI-ready prompts, markdown files and related reference data. Everything is organized to save hours of manual work collecting current data, cleaning it and joining it together. That makes it easier to move faster on analytics, due diligence, business planning and location research. Paid packages are built for commercial use, but some package contents include source-specific attribution or notice guidance. Review Licensing & Data Source Notices.
Lake County Population
Lake County had 11,059 residents in 2020. That was 1.3% lower than in 2010. Lake County had 217 fewer people in 2020 than it did in 2000, which points to a long-term population decline. The county is fairly spread out, with about 20 people per square mile. Some of the county's most populated postal areas include Madison, Wentworth and Chester.
Population Trend in Lake County SD
Lake County Population per 2000, 2010 and 2020 census counts with a baseline 2030 projection.
Lake County Zip Codes
Lake County has 7 zip codes. Some of the county's most populated zip codes include Madison (57042), Wentworth (57075) and Chester (57016). Madison is the largest zip by population, with about 8,131 residents or 74% of the county total. Together, the three largest zips account for about 90% of all county residents based on 2020 population estimates.
Most Populated Zip Codes in Lake County SD
| ZIP | Area | Population | Trend |
|---|---|---|---|
| 57042 | Madison | 8,131 | ▾ -3.4% |
| 57075 | Wentworth | 1,168 | ▴ 30.8% |
| 57016 | Chester | 689 | ▾ -0.6% |
| 57054 | Ramona | 430 | ▾ -14.3% |
| 57076 | Winfred | 317 | ▾ -39.2% |
| Download all zip code data | |||
Lake County Zip Code populations and trends per most recent census data.
Lake County Demographics
Lake County has a median age of 43.7, which makes the county a little older than South Dakota overall. About 19.7% of residents are under 18, while 23.6% are 65 or older. That gives the county a fairly even mix of younger families and older adults. The largest age group is 25 to 44 at about 25.9% of the population, which points to a solid working-age base. About 34.7% of adults have a bachelor's degree or higher, above the statewide figure of 31.1%. The county is mostly White by population, though Hispanic, Asian, Black and multiracial residents are also part of the local mix.
Key Demographics for Lake County SD
Median Age
43.7
Under 18
19.7%
Age 65+
23.6%
Bachelor's+
34.7%
Lake County School Districts
Lake County is served by 6 public school districts with 3,565 students enrolled in 2024. The largest districts on the county map are Madison Central 39-2, Sioux Valley 05-5 and Chester 39-1. Those three districts account for about 70% of public school enrollment in the map area. Total enrollment has grown modestly since 2017 across the districts shown on the county map.
Largest School Districts by Enrollment in Lake County SD
| District | Enrollment | Share | Trend |
|---|---|---|---|
| Madison Central School District 39-2 | 1,169 | 32.8% | ▾ -0.8% |
| Sioux Valley School District 05-5 | 742 | 20.8% | ▴ 3.8% |
| Chester School District 39-1 | 582 | 16.3% | ▴ 7.4% |
| McCook Central School District 43-7 | 455 | 12.8% | ▾ -3.6% |
| Colman-Egan School District 50-5 | 329 | 9.2% | ▴ 9.3% |
| Download all school district data | |||
Lake County school district enrollment and trends per most recent NCES reporting data.
Lake County Housing & Real Estate
Lake County has a median home value of $231,000 and a median gross rent of $868. About 71% of occupied homes in the county are owner-occupied, so the local housing market leans heavily toward ownership. Home values run below the South Dakota median, while rents come in below the state average. In March 2026, the median listing price was $432,450 and homes spent about 45 days on the market.
Lake County Housing Mix
Lake County housing mix: owner, renter and vacant units.
Lake County Housing Trends
Lake County median home value and rent trend (last 5 years).
Businesses in Lake County, SD
Lake County has 535 business listings across 233 categories. The largest categories in Lake County business listings are Churches & Religious Organizations (22, 4.1%), Lake (14, 2.6%), and Auto Repair (10, 1.9%). The full Lake County business listings dataset includes names, categories, addresses and contact details where available. Lake County packages also include U.S. Census County Business Patterns data with establishment counts, employment and payroll by industry sector.
Top Business Categories in Lake County, SD
| Category | Businesses | Share |
|---|---|---|
| Churches & Religious Organizations | 22 | 4.1% |
| Lake | 14 | 2.6% |
| Auto Repair | 10 | 1.9% |
| Contractors | 9 | 1.7% |
| Banks & Credit Unions | 9 | 1.7% |
| Bars & Nightlife | 9 | 1.7% |
| Landmark And Historical Building | 8 | 1.5% |
| Community & Nonprofits | 8 | 1.5% |
| Gas Stations | 8 | 1.5% |
| Public And Government Association | 8 | 1.5% |
Lake County Business Listings
| Business | Category | City |
|---|---|---|
| Residence Village | Accommodation | Madison |
| Q Bookkeeping & Payroll | Accountant | Wentworth |
| Mol Phonz | Active Life | Madison |
| CommissionSoup | Advertising Agency | Madison |
| Madison Farmers Elevator Company | Agricultural Cooperatives | Madison |
| Lake County International | Agricultural Service | Madison |
| Dakota Ethanol | Agriculture | Wentworth |
| Madison Municipal Airport | Airport | Madison |
| Cows -N- Canoes Country Mercantile | American Restaurants | Madison |
| Marzolf X-Kennel | Animal Shelters | Wentworth |
| Download Lake County business listings | ||
Lake County business listings sourced from Overture Maps. Includes locations with a high level of confidence.
Lake County Basemaps
Lake County map and data packages include a set of useful basemaps to help you get started quickly. These include a custom light grey canvas, USGS topo, imagery and other reference layers that make it easier to build clear, meaningful county maps using the included GIS layers, your own data or both. Pre-rendered map tiles for the light grey basemap are included so you can use them offline or host them on your own CDN.
Get the Full Lake County Data Package
This page shows a preview of what's included in the Lake County data package. The full package gives you a ready-to-use county data system with GIS layers, historical data, maps, database files and planning tools that save hours of manual data gathering, cleanup and joins. Everything is organized to help you skip data wrangling and start analysis faster.
- 20+ GIS layers for zip codes, school districts, roads, water, boundaries and more
- Historical county demographics, housing, income and trend data
- ZIP code population files and school district enrollment history
- Database files, markdowns, AI-ready prompts and documentation
- Map exports in PNG, JPEG, PDF, SVG and GeoTIFF formats
- Offline-ready data explorer, map and analytics tools
Paid packages support commercial use, client work, and derived outputs. Some package contents may include source-specific attribution or provider notices. See Licensing & Data Source Notices.
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Nearby Counties
Browse county data pages for the counties that border Lake County. These nearby pages include the same mix of county maps, demographic summaries, school district context, housing trends and package links.