ZIP Codes of Polk County, MN

Population & People
Population & People
Total Population
30,353
Household Income
Household Income
Median Income
$71,961
Housing
Housing
Total Housing Units
14,527
Business & Economy
Business & Economy
Total Businesses
731
Employment
Employment
Employment Rate
63.52%
Education
Education
Bachelor's Degree+
27.75%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 15 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:15 ZIP Codes (15 Standard, 0 PO Box, 0 Unique) [See All]
Area Code:218
Timezone:Central (GMT -06:00)
Local Time:2:12:38 PM
Population:30,353 [See All]
FIPS:27119
CBSA:Grand Forks, ND-MN
Land Area:1,922 sq mi
Water Area:29 sq mi
Coordinates:47.7062, -96.3007
Quick Link:
https://www.zip-codes.com/county/mn-polk.asp
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Minnesota's #36 most populous county
30,353 residents across 15 ZIPs — #36 of 93 Minnesota counties.

Standout ZIPs in this County


Most Populous
East Grand Forks · 10,679 people
35.2% of county total
Highest Income
Fisher · $106,250 median
1.5× county average
Largest Land Area
Crookston · 306.3 sq mi
Spans the most ground
Fastest Growth
East Grand Forks · 6.2% (10-yr)
10,060 → 10,679 residents
Most Educated
Crookston · 32.4% bachelor's+
2,073 of 6,393 adults 25+

Things worth knowing about Polk County


30,353 residents live across 15 ZIPs covering 1,922 sq mi, served by 15 distinct USPS-recognized cities.

Population moved from 31,256 to 30,353 from 2014 to 2024 — a -2.9% change. 3 ZIPs gained residents, 12 lost.

The county's wealthiest ZIP 56723 (Fisher, $106,250 median) and poorest ZIP 56646 (Gully, $48,750) are 56.1 miles apart — a 2.2× income gap across local geography.

Median home values vary 3.0× across this county — from $138,800 in 56684 (Trail) to $417,100 in 56736 (Mentor).

Density varies 26× across the county — from 2 people/sq mi in 56684 (Trail) to 58 in 56721 (East Grand Forks).

Educational attainment ranges from 13.9% bachelor's+ in 56684 (Trail) to 32.4% in 56716 (Crookston) — the breadth of educational profiles across the area.

Within Minnesota, this is the #36 most populous of 93 counties and ranks #62 for median household income .

Weighted by population, the typical household earns about $72,263 across the county — reflecting what a typical resident sees, not a simple ZIP average.

27.8% of adults age 25+ hold a bachelor's degree or higher (5,679 of 20,462 reporting).

15 Standard delivery, 0 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Polk County


Big & sparse

A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.

Total area
1,922
square miles
Avg density
15.8
people per sq mi
Population
30,353
across 15 ZIPs
Crookston
306.3 sq mi
8,903 residents
Fosston
195.9 sq mi
2,486 residents
Fertile
194.9 sq mi
1,891 residents

All ZIP Codes in Polk County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
56721East Grand ForksStandard10,679$82,525184.96.2%
56716CrookstonStandard8,903$59,744306.3-5.9%
56542FosstonStandard2,486$59,706195.9-16.2%
56540FertileStandard1,891$83,646194.9-0.7%
56556McintoshStandard1,312$61,786107.442.9%
56535ErskineStandard1,307$65,53695.3-6.0%
56723FisherStandard838$106,250123.0-9.3%
56736MentorStandard687$95,000104.1-32.7%
56592WingerStandard550$59,16752.53.8%
56523ClimaxStandard382$56,68579.9-23.8%
56722EuclidStandard377$94,375131.7-10.5%
56684TrailStandard280$73,750127.0-13.3%
56646GullyStandard266$48,75080.2-31.8%
56517BeltramiStandard255$92,500107.9-7.9%
56568NielsvilleStandard140$40,00031.1-16.2%

Adjacent & Nearby Counties