Cowlitz County, Washington
County seat: Kelso · Population 114,885 (2025) · 1,141 sq mi
Cowlitz County is the 12th most populous of Washington's 39 counties, with 114,885 people (2025 estimate). Its county seat is Kelso. The map shows its 5 cities and towns and the 5 neighboring counties.
Cowlitz County facts
- County seat
- Kelso
- Population (2025 estimate)
- 114,885 +3.8% since 2020
- Land area
- 1,141 sq mi 28th largest of 39
- Water area
- 25 sq mi
- Population density
- 101 per sq mi
- Established
- 1854
- Named after
- Cowlitz people ethnic group
- Largest city
- Longview 38,362
- Median household income
- $76,531
- Cities and towns
- 5 plus 5 CDPs
- ZIP codes
- 12
- Time zone
- Pacific
- FIPS code
- 53015
Cities and towns in Cowlitz County
Cowlitz County has 5 incorporated cities, towns and villages. Populations count the people living inside Cowlitz County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Longview | City | 38,362 | |
| Kelso (county seat) | City | 12,801 | |
| Woodland | City | 6,531 | Clark County |
| Kalama | City | 3,165 | |
| Castle Rock | City | 2,442 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Lexington | 4,413 | |
| Longview Heights | 4,357 | |
| Beacon Hill | 1,804 | |
| Ryderwood | 401 | |
| Cougar | 151 |
ZIP codes in Cowlitz County
12 ZIP codes reach into Cowlitz County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 98581
- 98601 also Clark County
- 98603
- 98609
- 98611
- 98616 also Skamania County
- 98625
- 98626
- 98632 also Wahkiakum County
- 98645
- 98649
- 98674 also Clark County
Population of Cowlitz County, 2020–2025
Cowlitz County grew by 4,157 people (+3.8%) between April 2020 and July 2025: 834 more deaths than births and a net gain of 4,985 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 111,014 |
| 2021 | 111,703 |
| 2022 | 112,021 |
| 2023 | 112,866 |
| 2024 | 113,764 |
| 2025 | 114,885 |
Neighboring counties
- Lewis County northeast · 88,062 people
- Clark County south · 532,119 people
- Columbia County, Oregon southwest · 54,091 people
- Skamania County east · 12,669 people
- Wahkiakum County west · 4,873 people
Printable Cowlitz 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) (121 KB)
- PNG (2400 px) (77 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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