County outline
Where Oliver County is located
Area breakdown
Land accounts for 98.8% of Oliver County’s measured area and water for 1.2%. Its combined area converts to 1,893.5 square kilometers or approximately 467,892 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 722.404 | 1,871.018 | 462,338.6 |
| Water | 8.678 | 22.476 | 5,553.9 |
| Total | 731.082 | 1,893.494 | 467,892.5 |
How Oliver County compares
By original Census land area, Oliver County ranks #49 of 53 in North Dakota and #1236 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.622 times the North Dakota county-equivalent median of 1,161.8 square miles. It accounts for 1% 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 Oliver County
The Census Bureau estimates that 1,898 people lived in Oliver County on July 1, 2025. That ranks #3,126 of 3,222 county equivalents nationally and #47 of 53 in North Dakota. Since the April 1, 2020 estimates base of 1,872, the population has grown by 26 (+1.4%), compared with +2.6% for North Dakota as a whole.
With 722.4 square miles of land, that is 2.6 people per square mile (1 per km²), placing Oliver County #3,016 nationally for density and #35 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 244 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 1,866 | 1,873 | 1,856 | 1,875 | 1,884 | 1,898 |
| Change | — | +7 | −17 | +19 | +9 | +14 |
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 Oliver County
1 incorporated place lies at least partly in Oliver County. Together they are home to 583 people (30.7%); the other 1,315 (69.3%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Center city, with 583 residents in the county.
Metropolitan area
Oliver County is an outlying county of the Bismarck, ND Metropolitan Statistical Area. Its 3 county equivalents have 139,750 residents on 4,281 square miles of land; Oliver County accounts for 16.9% of the land and 1.4% of the residents. By combined land it ranks #65 of 393 metropolitan areas, and #308 by population.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Burleigh County | 103,251 | 1,632.7 |
| Morton County | 34,601 | 1,925.9 |
| Oliver County | 1,898 | 722.4 |
ZIP codes
6 ZIP Code Tabulation Areas have land in Oliver County; 1 of them have most of their land inside the county, and the others mainly cover neighboring areas.
585235853058545585545856358571
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 Oliver County
Oliver County shares a land border with 4 county equivalents. Each of them has more land than Oliver County. The largest neighbor is McLean County (2,110.3 mi²) and the smallest is Mercer County (1,042.8 mi²). Together with its neighbors, Oliver County forms a block of 7,434 mi² of land, of which it holds 9.7%.
| Bordering county equivalent | Land mi² | Size vs. Oliver | Compare |
|---|---|---|---|
| McLean County | 2,110.3 | 2.9× larger | Compare |
| Morton County | 1,925.9 | 2.7× larger | Compare |
| Burleigh County | 1,632.7 | 2.3× larger | Compare |
| Mercer County | 1,042.8 | 1.4× larger | Compare |
How big is Oliver County compared with U.S. states?
Oliver County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.4 times as much. North Dakota’s county land could hold about 96 areas the size of Oliver County.
Another way to picture it: the same land area would fill a square about 26.9 miles (43.3 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 Oliver County?
Oliver County has more land than 1,986 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 Oliver County at #1,319 nationally by total area, 83 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 1.2%, compared with a national county-equivalent median of 1.2%. The two percentages are within 0.1 percentage points of each other. 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 Oliver County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1235 | Thurston County, Washington | 722.5 | Compare |
| #1236 | Oliver County, North Dakota | 722.4 | This county |
| #1237 | St. Croix County, Wisconsin | 722.2 | 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 47.118079, -101.331420. 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: 1,871,017,437 m²; AWATER: 22,475,760 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 Oliver County?
Oliver County, North Dakota has 722.4 square miles (1,871 km²) of land and 8.678 square miles of water, for a total area of 731.1 square miles. It ranks #1236 of 3,222 U.S. county equivalents by land area.
Is Oliver County the largest county in North Dakota?
No. Oliver County ranks #49 of 53 in North Dakota by land area. The largest is McKenzie County, with 2,760.1 square miles of land.
What counties border Oliver County?
Oliver County shares a land border with Mercer County, Morton County, McLean County, and Burleigh County.
What is the population of Oliver County?
The Census Bureau estimates Oliver County had 1,898 residents on July 1, 2025, ranking #3,126 of 3,222 county equivalents. That is 2.6 people per square mile of land.
What is the county seat of Oliver County?
The county seat of Oliver County is Center.
Is Oliver County part of a metropolitan area?
Yes. It is an outlying county of the Bismarck, ND Metropolitan Statistical Area, which has 3 county equivalents and 139,750 residents.
How many ZIP codes are in Oliver County?
6 ZIP Code Tabulation Areas have land in Oliver County, and 1 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Oliver County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.4 times as much land.
How many acres of land are in Oliver County?
The land measurement converts to approximately 462,339 acres. Including water, total area is approximately 467,892 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.