Polk County area

Population and density of Polk County

The Census Bureau estimates that 30,545 people lived in Polk County on July 1, 2025. That ranks #1,467 of 3,222 county equivalents nationally and #35 of 87 in Minnesota. Since the April 1, 2020 estimates base of 31,203, the population has declined by 658 (−2.1%), compared with +2.2% for Minnesota as a whole.

With 1,971 square miles of land, that is 15 people per square mile (6 per km²), placing Polk County #2,458 nationally for density and #64 in Minnesota. The median county equivalent has 47 people per square mile; the Minnesota median is 27. Put another way, there are about 41 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 Polk County

Polk County is divided into 73 municipalities and townships. In Minnesota, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is East Grand Forks city, with 8,906 residents (29.2% of the county). The largest by land is Grove Park-Tilden township, at 69.2 mi², or 3.5% of the county’s land. The county seat, Crookston city, has 7,375 residents.

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Polk County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Polk County is a central county of the Grand Forks, ND-MN Metropolitan Statistical Area. Its 2 county equivalents have 105,046 residents on 3,407.2 square miles of land; Polk County accounts for 57.8% of the land and 29.1% of the residents. By combined land it ranks #86 of 393 metropolitan areas, and #358 by population.

ZIP codes

25 ZIP Code Tabulation Areas have land in Polk County; 16 of them have most of their land inside the county, and the others mainly cover neighboring areas.

56517565235653556540565425655656568565925662156644566465665156684567015671056715567165672156722567235673656742567445675056762

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 Polk County

Polk County shares a land border with 8 county equivalents, including 2 in North Dakota. It has more land than every one of them. The largest neighbor is Marshall County (1,775.1 mi²) and the smallest is Red Lake County (432.4 mi²). Together with its neighbors, Polk County forms a block of 9,522.7 mi² of land, of which it holds 20.7%.

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

Polk 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 2.5 times as much land (4,842.5 mi²). Minnesota’s county land could hold about 40 areas the size of Polk County.

Another way to picture it: the same land area would fill a square about 44.4 miles (71.4 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 Polk County?

Polk County has more land than 2,932 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 Polk County at #319 nationally by total area, 29 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 1.3%, compared with a national county-equivalent median of 1.2% — 0.2 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 Polk 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.