County Maps US

Lake County, South Dakota

A county in South Dakota, ranked 16 of 66 by population.

CountyFIPS 46079

Within South Dakota
Lake County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Madison, the county seat, located via the 2025 Census Gazetteer.

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Population
10,993
-22 (-0.2%) since 2020
Land area
562.9
square miles. A further 2.1% of the total area is water
Population density
19.5
people per square mile, computed rather than published
County seat
Madison
Seat of county government.
Established
1873
152 years ago
Largest city
Madison city
Population 6,065.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Lake County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Lake County, South Dakota from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 797 by 800 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Lake County ranks

Position among the 66 counties of South Dakota, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn South DakotaNationally
Population10,99316th of 662,346th of 3,144
Land area562.9 sq mi56th of 661,834th of 3,144
Population density19.5 per sq mi13th of 662,264th of 3,144
Median household income$76,80817th of 66735th of 3,143

Full data for Lake County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population10,993Vintage 2025 Population Estimates
Population in 202011,015Vintage 2025 Population Estimates
2020 estimates base?11,063Vintage 2025 Population Estimates
Land area562.9 sq mi2025 Gazetteer Files
Water area12.3 sq mi2025 Gazetteer Files
Total area575.2 sq mi2025 Gazetteer Files
Population density?19.5 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$76,808American Community Survey 2020-2024 5-Year Estimates
Median home value$247,600American Community Survey 2020-2024 5-Year Estimates
Median age43.8American Community Survey 2020-2024 5-Year Estimates
Households4,716American Community Survey 2020-2024 5-Year Estimates
Housing units5,797American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
-2
109 births, 111 deaths
Net migration
-49
More people moved out than moved in.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 6 areas bordering Lake County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Moody CountySouth Dakota24 mi6,632
Miner CountySouth Dakota24 mi2,281
Minnehaha CountySouth Dakota12 mi212,691
McCook CountySouth Dakota12 mi5,964
Brookings CountySouth Dakota12 mi37,635
Kingsbury CountySouth Dakota12 mi5,284

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 66 counties of South Dakota

Open the interactive South Dakota county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.