Corson County area

Corson County, South Dakota covers 2,529.7 square miles: 2,469.7 square miles of land and 60 square miles of water. Its county seat is McIntosh. An estimated 3,781 people lived there in 2025.

Official Census measurements · GEOID 460312026 Gazetteer · retrieved September 27, 2026
Land area2,469.7 mi²
Water area60 mi²
Population (2025)3,781
People per mi²1.5

County outline

Generalized outline of Corson County, South Dakota
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Corson County is located

Corson County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 97.6% of Corson County’s measured area and water for 2.4%. Its combined area converts to 6,551.8 square kilometers or approximately 1,618,977 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land2,469.6946,396.4781,580,604.2
Water59.957155.28838,372.5
Total2,529.6516,551.7661,618,976.6

How Corson County compares

By original Census land area, Corson County ranks #5 of 66 in South Dakota and #220 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 2.716 times the South Dakota county-equivalent median of 909.3 square miles. It accounts for 3.3% of the combined county land area in the state.

See the complete South Dakota ranking · What counts as a county equivalent?

Population and density of Corson County

The Census Bureau estimates that 3,781 people lived in Corson County on July 1, 2025. That ranks #2,974 of 3,222 county equivalents nationally and #42 of 66 in South Dakota. Since the April 1, 2020 estimates base of 3,899, the population has declined by 118 (−3%), compared with +5.5% for South Dakota as a whole.

With 2,469.7 square miles of land, that is 1.5 people per square mile (0.59 per km²), placing Corson County #3,101 nationally for density and #58 in South Dakota. The median county equivalent has 47 people per square mile; the South Dakota median is 5.7. Put another way, there are about 418 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate3,8913,8463,8093,7763,7773,781
Change—−45−37−33+1+4

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Corson County

3 incorporated places lie at least partly in Corson County. Together they are home to 703 people (18.6%); the other 3,078 (81.4%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is McLaughlin city, with 551 residents in the county. The county seat, McIntosh city, has 109 residents. By land, McIntosh city is the largest at 0.73 mi².

Incorporated placePopulation 2025Since 2020Land mi²
McLaughlin city551−3%0.404
McIntosh cityCounty seat109−4.4%0.73
Morristown town43−2.3%0.351

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Corson County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Corson County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.

ZIP codes

16 ZIP Code Tabulation Areas have land in Corson County; 10 of them have most of their land inside the county, and the others mainly cover neighboring areas.

57601576215763357634576385763957641576425764457645576565765757658576595766058568

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Corson County

Corson County shares a land border with 7 county equivalents, including 2 in North Dakota. It has more land than 6 of them. The largest neighbor is Perkins County (2,870.5 mi²) and the smallest is Walworth County (707.5 mi²). Together with its neighbors, Corson County forms a block of 13,647.5 mi² of land, of which it holds 18.1%.

Map of Corson County and the 7 county equivalents that border it Sioux County, North Dakota: 1,094.1 mi² landDewey County, South Dakota: 2,302.4 mi² landPerkins County, South Dakota: 2,870.5 mi² landCampbell County, South Dakota: 733.8 mi² landZiebach County, South Dakota: 1,961.2 mi² landWalworth County, South Dakota: 707.5 mi² landEmmons County, North Dakota: 1,508.4 mi² land
Corson County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. CorsonCompare
Perkins County2,870.51.2× largerCompare
Dewey County2,302.41.1× smallerCompare
Ziebach County1,961.21.3× smallerCompare
Emmons CountyNorth Dakota1,508.41.6× smallerCompare
Sioux CountyNorth Dakota1,094.12.3× smallerCompare
Campbell County733.83.4× smallerCompare
Walworth County707.53.5× smallerCompare

How big is Corson County compared with U.S. states?

Corson County has more land than 2 of the 50 states. It is about 1.3 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 2 times as much land (4,842.5 mi²). South Dakota’s county land could hold about 31 areas the size of Corson County.

Land area: Corson County and the closest-sized states
Delaware1,948.6 mi²
Corson County2,469.7 mi²
Connecticut4,842.5 mi²

Another way to picture it: the same land area would fill a square about 49.7 miles (80 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Corson County?

Corson County has more land than 3,002 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Corson County2,469.7 mi²
South Dakota median909.3 mi²
National median604.5 mi²

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Corson County at #232 nationally by total area, 12 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 2.4%, compared with a national county-equivalent median of 1.2% — 1.2 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Corson County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#219Stevens County, Washington2,477.1Compare
#220Corson County, South Dakota2,469.7This county
#221Wayne County, Utah2,461.1Compare

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.

Representative coordinates

The Census internal point is 45.688224, -101.185314. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.

Source and precision

U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 6,396,478,560 m²; AWATER: 155,287,099 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Corson County?

Corson County, South Dakota has 2,469.7 square miles (6,396.5 km²) of land and 60 square miles of water, for a total area of 2,529.7 square miles. It ranks #220 of 3,222 U.S. county equivalents by land area.

Is Corson County the largest county in South Dakota?

No. Corson County ranks #5 of 66 in South Dakota by land area. The largest is Meade County, with 3,470.9 square miles of land.

What counties border Corson County?

Corson County shares a land border with Sioux County, North Dakota, Dewey County, Perkins County, Campbell County, Ziebach County, Walworth County, and Emmons County, North Dakota.

What is the population of Corson County?

The Census Bureau estimates Corson County had 3,781 residents on July 1, 2025, ranking #2,974 of 3,222 county equivalents. That is 1.5 people per square mile of land.

What is the county seat of Corson County?

The county seat of Corson County is McIntosh.

What cities and towns are in Corson County?

Corson County has 3 incorporated places. The most populous are McLaughlin city, McIntosh city, and Morristown town; 3,078 residents live outside any incorporated place.

Is Corson County part of a metropolitan area?

No. Corson County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.

How many ZIP codes are in Corson County?

16 ZIP Code Tabulation Areas have land in Corson County, and 10 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Corson County compare with U.S. states?

It has more land than 2 of the 50 states, including Delaware (1,948.6 square miles of land).

How many acres of land are in Corson County?

The land measurement converts to approximately 1,580,604 acres. Including water, total area is approximately 1,618,977 acres. One square mile equals 640 acres.

Why might another source show a different area?

Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.

Can this establish a property boundary?

No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.

Cite this county

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