Iowa County Maps
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Iowa has 99 counties, a population of more than 3 million people, about 970 zip codes and 677 public school districts. Those counties vary widely in population, school enrollment, zip code coverage and local boundary structure. Polk County has the largest population in the state, while Adams County has the smallest. Browse the map, population, zip codes, school districts, subdivisions and county list sections below to explore further. Or, simply start typing in the box below to go directly to that county.
Interactive Iowa County Map
This Iowa county map preview highlights population-by-county context, ZIP code coverage, school districts, and local boundary structure. Full statewide and county-level data packages are available when you need complete downloadable datasets. Click or tap any county to view its maps, trends and data.
Start with a free preview, or go straight to the full Iowa dataset .
Iowa Population By County
Iowa's population was over 3 million in 2020, up 144,015 (4.73%) residents from 2010. Polk County had the largest population in the state with 492,401 people. Linn and Scott Counties also stand out as major population centers. Adams County was the least populated area in Iowa with only 3,704 residents. The table below compares Iowa county populations and recent population trends.
The Most Populated Counties In Iowa
| County | Population | Trend (2010-2020) |
|---|---|---|
| Polk County | 492,401 | ▴ 14.34% |
| Linn County | 230,299 | ▴ 9.03% |
| Scott County | 174,669 | ▴ 5.72% |
| Johnson County | 152,854 | ▴ 16.79% |
| Black Hawk County | 131,144 | ▴ 0.04% |
| Download all county population data | ||
County populations reflect the latest state serving context (2020).
Iowa County Map With ZIP Codes
Iowa has about 970 zip codes statewide. Polk County contains the most zip codes, with 33. County-level zip code maps give a faster and clearer way to understand local coverage as zip boundaries can span county and municipal lines. The maps below highlight a few Iowa counties.
Iowa School Districts By County
Iowa has 677 public school districts with 866,301 students enrolled as of 2024. Polk County stands out for both district count and total enrollment. Audubon County posted the largest recent enrollment gain. The table below compares county level school district totals and recent enrollment trends across the state.
Largest School Districts in Iowa
| County | Districts | Enrollment | Trend |
|---|---|---|---|
| Polk County | 15 | 85,971 | ▾ 1.42% |
| Linn County | 14 | 39,736 | ▾ 1.29% |
| Boone County | 13 | 14,299 | ▾ 1.36% |
| Dallas County | 11 | 35,869 | ▴ 0.39% |
| Johnson County | 11 | 31,835 | ▴ 0.78% |
| Download all school district data | |||
School district enrollment and trend values reflect the most recent state-level context (2024).
Iowa County Map With Subdivisions
Iowa has about 1,663 local subdivisions statewide. These boundaries add another layer of detail within counties and help show how local subdivision lines fit inside county boundaries. The previews below highlight a few Iowa counties with subdivision map coverage.
Get the Full Iowa Data Package
The sections above provide a preview of Iowa county maps and county-level data. The full package includes complete statewide coverage with ready-to-use files for mapping, planning, and analysis.
Everything is organized to save hours of data collection, cleanup, and integration work.
- County map exports and boundary coverage for every county in Iowa
- Statewide GIS layers for ZIP codes, subdivisions, school districts, roads, water, and political boundaries
- Population, demographics, school, housing, and trend context aligned across counties
- Database files, map-ready exports, and documentation designed for faster research workflows
Includes GIS layers, maps, demographics, analytics, database files and planning tools.