County outline
Where Harding County is located
Area breakdown
Land accounts for 99.8% of Harding County’s measured area and water for 0.2%. Its combined area converts to 6,936.3 square kilometers or approximately 1,713,994 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 2,671.57 | 6,919.335 | 1,709,804.8 |
| Water | 6.546 | 16.954 | 4,189.4 |
| Total | 2,678.116 | 6,936.289 | 1,713,994.2 |
How Harding County compares
By original Census land area, Harding County ranks #4 of 66 in South Dakota and #196 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 2.938 times the South Dakota county-equivalent median of 909.3 square miles. It accounts for 3.5% 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 Harding County
The Census Bureau estimates that 1,331 people lived in Harding County on July 1, 2025. That ranks #3,168 of 3,222 county equivalents nationally and #64 of 66 in South Dakota. Since the April 1, 2020 estimates base of 1,305, the population has grown by 26 (+2%), compared with +5.5% for South Dakota as a whole.
With 2,671.6 square miles of land, that is 0.5 people per square mile (0.19 per km²), placing Harding County #3,194 nationally for density and #66 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 1,285 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 1,303 | 1,321 | 1,325 | 1,313 | 1,312 | 1,331 |
| Change | — | +18 | +4 | −12 | −1 | +19 |
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 Harding County
2 incorporated places lie at least partly in Harding County. Together they are home to 427 people (32.1%); the other 904 (67.9%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Buffalo town, with 358 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Buffalo townCounty seat | 358 | +2% | 0.554 |
| Camp Crook town | 69 | +16.9% | 0.139 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Harding County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Harding 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
12 ZIP Code Tabulation Areas have land in Harding County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
576495765057651577175772057724577555776057776586235864958653
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 Harding County
Harding County shares a land border with 6 county equivalents, including 4 in North Dakota and Montana. It has more land than 4 of them. The largest neighbor is Carter County (3,340.5 mi²) and the smallest is Adams County (987.5 mi²). Together with its neighbors, Harding County forms a block of 14,902.5 mi² of land, of which it holds 17.9%.
| Bordering county equivalent | Land mi² | Size vs. Harding | Compare |
|---|---|---|---|
| Carter CountyMontana | 3,340.5 | 1.3× larger | Compare |
| Perkins County | 2,870.5 | 1.1× larger | Compare |
| Butte County | 2,250 | 1.2× smaller | Compare |
| Fallon CountyMontana | 1,620.6 | 1.6× smaller | Compare |
| Bowman CountyNorth Dakota | 1,161.8 | 2.3× smaller | Compare |
| Adams CountyNorth Dakota | 987.5 | 2.7× smaller | Compare |
How big is Harding County compared with U.S. states?
Harding County has more land than 2 of the 50 states. It is about 1.4 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.8 times as much land (4,842.5 mi²). South Dakota’s county land could hold about 28 areas the size of Harding County.
Another way to picture it: the same land area would fill a square about 51.7 miles (83.2 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 Harding County?
Harding County has more land than 3,026 of the other 3,221 county equivalents in the dataset.
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 Harding County at #210 nationally by total area, 14 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 0.2%, compared with a national county-equivalent median of 1.2% — 0.9 percentage points lower. 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 Harding County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #195 | St. Lawrence County, New York | 2,679.5 | Compare |
| #196 | Harding County, South Dakota | 2,671.6 | This county |
| #197 | Itasca County, Minnesota | 2,667.5 | Compare |
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 45.596514, -103.474266. 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: 6,919,333,321 m²; AWATER: 16,954,253 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Harding County?
Harding County, South Dakota has 2,671.6 square miles (6,919.3 km²) of land and 6.546 square miles of water, for a total area of 2,678.1 square miles. It ranks #196 of 3,222 U.S. county equivalents by land area.
Is Harding County the largest county in South Dakota?
No. Harding County ranks #4 of 66 in South Dakota by land area. The largest is Meade County, with 3,470.9 square miles of land.
What counties border Harding County?
Harding County shares a land border with Butte County, Perkins County, Bowman County, North Dakota, Carter County, Montana, Fallon County, Montana, and Adams County, North Dakota.
What is the population of Harding County?
The Census Bureau estimates Harding County had 1,331 residents on July 1, 2025, ranking #3,168 of 3,222 county equivalents. That is 0.5 people per square mile of land.
What is the county seat of Harding County?
The county seat of Harding County is Buffalo.
What cities and towns are in Harding County?
Harding County has 2 incorporated places. The most populous are Buffalo town and Camp Crook town; 904 residents live outside any incorporated place.
Is Harding County part of a metropolitan area?
No. Harding County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Harding County?
12 ZIP Code Tabulation Areas have land in Harding County, and 6 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Harding 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 Harding County?
The land measurement converts to approximately 1,709,805 acres. Including water, total area is approximately 1,713,994 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.