Story County area

Population and density of Story County

The Census Bureau estimates that 101,291 people lived in Story County on July 1, 2025. That ranks #624 of 3,222 county equivalents nationally and #8 of 99 in Iowa. Since the April 1, 2020 estimates base of 98,541, the population has grown by 2,750 (+2.8%), compared with +1.5% for Iowa as a whole.

With 572.5 square miles of land, that is 177 people per square mile (68 per km²), placing Story County #685 nationally for density and #7 in Iowa. The median county equivalent has 47 people per square mile; the Iowa median is 26. Put another way, there are about 3.6 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 Story County

15 incorporated places lie at least partly in Story County. Together they are home to 91,950 people (90.8%); the other 9,341 (9.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Ames city, with 68,220 residents in the county. The county seat, Nevada city, has 6,974 residents. Among places with at least 1,000 residents in 2020, Gilbert city grew fastest since then (+15.1%).

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

Metropolitan area

Story County is a central county of the Ames, IA Metropolitan Statistical Area. Its 2 county equivalents have 128,090 residents on 1,143 square miles of land; Story County accounts for 50.1% of the land and 79.1% of the residents. By combined land it ranks #264 of 393 metropolitan areas, and #328 by population. It belongs to the Des Moines-West Des Moines-Ames, IA Combined Statistical Area.

ZIP codes

23 ZIP Code Tabulation Areas have land in Story County; 15 of them have most of their land inside the county, and the others mainly cover neighboring areas.

5001050012500135001450046500555005650105501245013450154501615020150206502265023050236502395024350244502475024850278

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 Story County

Story County shares a land border with 6 county equivalents. It has more land than 3 of them. The largest neighbor is Jasper County (730.4 mi²) and the smallest is Hardin County (569.3 mi²). Together with its neighbors, Story County forms a block of 4,164.7 mi² of land, of which it holds 13.7%.

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

Story 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. Iowa’s county land could hold about 98 areas the size of Story 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 Story County?

Story County has more land than 1,474 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 Story County at #1,893 nationally by total area, 145 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 Story 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.