Cass County area

Population and density of Cass County

The Census Bureau estimates that 201,794 people lived in Cass County on July 1, 2025. That ranks #357 of 3,222 county equivalents nationally and #1 of 53 in North Dakota. Since the April 1, 2020 estimates base of 184,533, the population has grown by 17,261 (+9.4%), compared with +2.6% for North Dakota as a whole.

With 1,764.9 square miles of land, that is 114 people per square mile (44 per km²), placing Cass County #908 nationally for density and #1 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 5.6 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 Cass County

27 incorporated places lie at least partly in Cass County. Together they are home to 194,667 people (96.5%); the other 7,127 (3.5%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Fargo city, with 136,275 residents in the county. Among places with at least 1,000 residents in 2020, Horace city grew fastest since then (+118.4%).

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

Metropolitan area

Cass County is a central county of the Fargo, ND-MN Metropolitan Statistical Area. Its 2 county equivalents have 269,528 residents on 2,810.1 square miles of land; Cass County accounts for 62.8% of the land and 74.9% of the residents. By combined land it ranks #107 of 393 metropolitan areas, and #188 by population. It belongs to the Fargo-Wahpeton, ND-MN Combined Statistical Area.

ZIP codes

30 ZIP Code Tabulation Areas have land in Cass County; 25 of them have most of their land inside the county, and the others mainly cover neighboring areas.

580025800458005580065800758011580125802158027580295803158035580365803858042580465804758048580515805258059580645806858071580785807958102581035810458105

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 Cass County

Cass County shares a land border with 7 county equivalents, including 2 in Minnesota. It has more land than every one of them. The largest neighbor is Barnes County (1,491.6 mi²) and the smallest is Steele County (712.1 mi²). Together with its neighbors, Cass County forms a block of 9,046.6 mi² of land, of which it holds 19.5%.

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

Cass County has more land than 1 of the 50 states. It is about 1.7 times the land area of Rhode Island (1,033.9 mi²), while Delaware, the next larger state, has 1.1 times as much land (1,948.6 mi²). North Dakota’s county land could hold about 39 areas the size of Cass County.

Another way to picture it: the same land area would fill a square about 42 miles (67.6 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 Cass County?

Cass County has more land than 2,885 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 Cass County at #380 nationally by total area, 43 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% — 1 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 Cass 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.