County outline
Where Dunn County is located
Area breakdown
Land accounts for 96.5% of Dunn County’s measured area and water for 3.5%. Its combined area converts to 5,392.7 square kilometers or approximately 1,332,568 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 2,008.565 | 5,202.159 | 1,285,481.6 |
| Water | 73.573 | 190.553 | 47,086.7 |
| Total | 2,082.138 | 5,392.713 | 1,332,568.3 |
How Dunn County compares
By original Census land area, Dunn County ranks #6 of 53 in North Dakota and #284 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.729 times the North Dakota county-equivalent median of 1,161.8 square miles. It accounts for 2.9% of the combined county land area in the state.
See the complete North Dakota ranking · What counts as a county equivalent?
Population and density of Dunn County
The Census Bureau estimates that 4,058 people lived in Dunn County on July 1, 2025. That ranks #2,958 of 3,222 county equivalents nationally and #26 of 53 in North Dakota. Since the April 1, 2020 estimates base of 4,100, the population has declined by 42 (−1%), compared with +2.6% for North Dakota as a whole.
With 2,008.6 square miles of land, that is 2 people per square mile (0.78 per km²), placing Dunn County #3,066 nationally for density and #43 in North Dakota. The median county equivalent has 47 people per square mile; the North Dakota median is 3.7. Put another way, there are about 317 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 4,093 | 4,007 | 3,990 | 4,027 | 3,973 | 4,058 |
| Change | — | −86 | −17 | +37 | −54 | +85 |
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 Dunn County
4 incorporated places lie at least partly in Dunn County. Together they are home to 1,464 people (36.1%); the other 2,594 (63.9%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Killdeer city, with 912 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Killdeer city | 912 | −2.7% | 2.151 |
| Dunn Center city | 235 | +2.2% | 0.391 |
| Halliday city | 231 | −2.9% | 0.461 |
| Dodge city | 86 | −1.1% | 0.467 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Dunn County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Dunn County is an outlying county of the Dickinson, ND Micropolitan Statistical Area. Its 3 county equivalents have 39,142 residents on 4,492 square miles of land; Dunn County accounts for 44.7% of the land and 10.4% of the residents. By combined land it ranks #29 of 542 micropolitan areas, and #329 by population.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Stark County | 34,013 | 1,334.9 |
| Dunn County | 4,058 | 2,008.6 |
| Billings County | 1,071 | 1,148.5 |
ZIP codes
13 ZIP Code Tabulation Areas have land in Dunn County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.
58601586255862658630586365863858640586425864458652586565875758854
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 Dunn County
Dunn County shares a land border with 6 county equivalents. It has more land than 4 of them. The largest neighbor is McKenzie County (2,760.1 mi²) and the smallest is Mercer County (1,042.8 mi²). Together with its neighbors, Dunn County forms a block of 12,230.2 mi² of land, of which it holds 16.4%.
| Bordering county equivalent | Land mi² | Size vs. Dunn | Compare |
|---|---|---|---|
| McKenzie County | 2,760.1 | 1.4× larger | Compare |
| McLean County | 2,110.3 | 1.1× larger | Compare |
| Mountrail County | 1,825.2 | 1.1× smaller | Compare |
| Stark County | 1,334.9 | 1.5× smaller | Compare |
| Billings County | 1,148.5 | 1.7× smaller | Compare |
| Mercer County | 1,042.8 | 1.9× smaller | Compare |
How big is Dunn County compared with U.S. states?
Dunn County has more land than 2 of the 50 states. It is about 1 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 2.4 times as much land (4,842.5 mi²). North Dakota’s county land could hold about 34 areas the size of Dunn County.
Another way to picture it: the same land area would fill a square about 44.8 miles (72.1 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 Dunn County?
Dunn County has more land than 2,938 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 Dunn County at #306 nationally by total area, 22 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 3.5%, compared with a national county-equivalent median of 1.2% — 2.4 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 Dunn County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #283 | Ward County, North Dakota | 2,013 | Compare |
| #284 | Dunn County, North Dakota | 2,008.6 | This county |
| #285 | Utah County, Utah | 2,004.5 | 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 47.354021, -102.611924. 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: 5,202,158,267 m²; AWATER: 190,552,952 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 Dunn County?
Dunn County, North Dakota has 2,008.6 square miles (5,202.2 km²) of land and 73.6 square miles of water, for a total area of 2,082.1 square miles. It ranks #284 of 3,222 U.S. county equivalents by land area.
Is Dunn County the largest county in North Dakota?
No. Dunn County ranks #6 of 53 in North Dakota by land area. The largest is McKenzie County, with 2,760.1 square miles of land.
What counties border Dunn County?
Dunn County shares a land border with McKenzie County, Stark County, Mercer County, Billings County, McLean County, and Mountrail County.
What is the population of Dunn County?
The Census Bureau estimates Dunn County had 4,058 residents on July 1, 2025, ranking #2,958 of 3,222 county equivalents. That is 2 people per square mile of land.
What is the county seat of Dunn County?
The county seat of Dunn County is Manning.
What cities and towns are in Dunn County?
Dunn County has 4 incorporated places. The most populous are Killdeer city, Dunn Center city, Halliday city, and Dodge city; 2,594 residents live outside any incorporated place.
Is Dunn County part of a metropolitan area?
Yes. It is an outlying county of the Dickinson, ND Micropolitan Statistical Area, which has 3 county equivalents and 39,142 residents.
How many ZIP codes are in Dunn County?
13 ZIP Code Tabulation Areas have land in Dunn County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Dunn 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 Dunn County?
The land measurement converts to approximately 1,285,482 acres. Including water, total area is approximately 1,332,568 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.