Isabella County area

Population and density of Isabella County

The Census Bureau estimates that 64,691 people lived in Isabella County on July 1, 2025. That ranks #858 of 3,222 county equivalents nationally and #31 of 83 in Michigan. Since the April 1, 2020 estimates base of 64,388, the population has grown by 303 (+0.5%), compared with +0.5% for Michigan as a whole.

With 572.7 square miles of land, that is 113 people per square mile (44 per km²), placing Isabella County #914 nationally for density and #31 in Michigan. The median county equivalent has 47 people per square mile; the Michigan median is 62. Put another way, there are about 5.7 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 Isabella County

Isabella County is divided into 18 municipalities and townships. In Michigan, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is Mount Pleasant city, with 20,925 residents (32.3% of the county). The largest by land is Wise township, at 36.5 mi², or 6.4% of the county’s land. Among those with at least 1,000 residents in 2020, Fremont township grew fastest since then (+4.9%).

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

Metropolitan area

Isabella County is a central county of the Mount Pleasant, MI Micropolitan Statistical Area. Isabella County is the area’s only county equivalent, so the micro area has the same 572.7 square miles of land. By combined land it ranks #371 of 542 micropolitan areas, and #142 by population. It belongs to the Mount Pleasant-Alma, MI Combined Statistical Area.

ZIP codes

16 ZIP Code Tabulation Areas have land in Isabella County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.

48617486184862248632488294885848859488774887848880488834889348896493054931049340

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 Isabella County

Isabella County shares a land border with 5 county equivalents. It has more land than 4 of them. The largest neighbor is Montcalm County (705.3 mi²) and the smallest is Midland County (518.4 mi²). Together with its neighbors, Isabella County forms a block of 3,484.4 mi² of land, of which it holds 16.4%.

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

Isabella County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.8 times as much. Michigan’s county land could hold about 99 areas the size of Isabella County.

Another way to picture it: the same land area would fill a square about 23.9 miles (38.5 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 Isabella County?

Isabella County has more land than 1,476 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 Isabella County at #1,848 nationally by total area, 102 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 0.9%, compared with a national county-equivalent median of 1.2% — 0.3 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 Isabella 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.