Williams County area

Population and density of Williams County

The Census Bureau estimates that 41,767 people lived in Williams County on July 1, 2025. That ranks #1,180 of 3,222 county equivalents nationally and #5 of 53 in North Dakota. Since the April 1, 2020 estimates base of 40,952, the population has grown by 815 (+2%), compared with +2.6% for North Dakota as a whole.

With 2,077.6 square miles of land, that is 20 people per square mile (7.8 per km²), placing Williams County #2,322 nationally for density and #6 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 32 acres of land per resident.

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 Williams County

8 incorporated places lie at least partly in Williams County. Together they are home to 33,040 people (79.1%); the other 8,727 (20.9%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Williston city, with 29,522 residents in the county. Among places with at least 1,000 residents in 2020, Williston city grew fastest since then (+1.3%).

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

Metropolitan area

Williams County is a central county of the Williston, ND Micropolitan Statistical Area. Williams County is the area’s only county equivalent, so the micro area has the same 2,077.6 square miles of land. By combined land it ranks #76 of 542 micropolitan areas, and #307 by population.

ZIP codes

10 ZIP Code Tabulation Areas have land in Williams County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

58755587955880158830588435884558849588525885358856

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 Williams County

Williams County shares a land border with 6 county equivalents, including 2 in Montana. It has more land than 4 of them. The largest neighbor is McKenzie County (2,760.1 mi²) and the smallest is Burke County (1,103.6 mi²). Together with its neighbors, Williams County forms a block of 13,059.1 mi² of land, of which it holds 15.9%.

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

Williams County has more land than 2 of the 50 states. It is about 1.1 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 2.3 times as much land (4,842.5 mi²). North Dakota’s county land could hold about 33 areas the size of Williams County.

Another way to picture it: the same land area would fill a square about 45.6 miles (73.4 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 Williams County?

Williams County has more land than 2,948 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 Williams County at #293 nationally by total area, 19 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 3.3%, compared with a national county-equivalent median of 1.2% — 2.1 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 Williams County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.