Benton County, Washington
County seat: Prosser · Population 221,722 (2025) · 1,700 sq mi
Benton County is the 10th most populous of Washington's 39 counties, with 221,722 people (2025 estimate). Its county seat is Prosser. The map shows its 5 cities and towns and the 7 neighboring counties.
Benton County facts
- County seat
- Prosser
- Population (2025 estimate)
- 221,722 +7.2% since 2020
- Land area
- 1,700 sq mi 22nd largest of 39
- Water area
- 60 sq mi
- Population density
- 130 per sq mi
- Established
- 1905
- Same name
- One of 9 Benton Counties in the US
- Named after
- Thomas Hart Benton State Senator from Tennessee, Senator and U.S. Representative from Missouri (1782–1858)
- Largest city
- Kennewick 88,366
- Median household income
- $89,874
- Cities and towns
- 5 plus 1 CDPs
- ZIP codes
- 12
- Time zone
- Pacific
- FIPS code
- 53005
Cities and towns in Benton County
Benton County has 5 incorporated cities, towns and villages. Populations count the people living inside Benton County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Kennewick | City | 88,366 | |
| Richland | City | 65,258 | |
| West Richland | City | 19,257 | |
| Prosser (county seat) | City | 6,654 | |
| Benton City | City | 4,019 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Finley | 5,634 |
ZIP codes in Benton County
12 ZIP codes reach into Benton County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 98930 also Yakima County
- 98944 also Yakima County
- 99320
- 99336
- 99337
- 99338
- 99345
- 99346
- 99350 also Klickitat and Yakima counties
- 99352
- 99353
- 99354
Population of Benton County, 2020–2025
Benton County grew by 14,859 people (+7.2%) between April 2020 and July 2025: 3,401 more births than deaths and a net gain of 11,507 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 207,408 |
| 2021 | 210,612 |
| 2022 | 212,818 |
| 2023 | 215,705 |
| 2024 | 218,931 |
| 2025 | 221,722 |
Neighboring counties
- Franklin County northeast · 102,612 people
- Yakima County west · 259,185 people
- Grant County north · 105,727 people
- Morrow County, Oregon south · 12,602 people
- Umatilla County, Oregon southeast · 81,119 people
- Walla Walla County east · 62,361 people
- Klickitat County west · 24,331 people
Printable Benton County map
The PDF is a vector file with real text: it prints sharp on Letter paper and you can search it for a town. The PNG is 2400 pixels wide for slides and documents. Both are free to use with a credit to WhichCounty.
- PDF (Letter) (125 KB)
- PNG (2400 px) (94 KB)
Paste this code to embed the map on your site:
Sources
- Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files (1:500,000).
- Population: Census Bureau county and city estimates, Vintage 2025. CDP populations: American Community Survey 2020–2024.
- Places and ZIP codes: Census Bureau 2026 Gazetteer and 2020 ZIP Code Tabulation Area relationship files.
- County seat, founding year and name origin: Wikidata (CC0), checked against state sources.
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