Colusa County, California
County seat: Colusa · Population 21,836 (2025) · 1,151 sq mi
Colusa County is the 50th most populous of California's 58 counties, with 21,836 people (2025 estimate). Its county seat is Colusa. The map shows its 2 cities and towns and the 5 neighboring counties.
Colusa County facts
- County seat
- Colusa
- Population (2025 estimate)
- 21,836 ±0% since 2020
- Land area
- 1,151 sq mi 39th largest of 58
- Water area
- 6 sq mi
- Population density
- 19 per sq mi
- Established
- 1850
- Named after
- Rancho Colus Mexican land grant in California
- Largest city
- Colusa 6,519
- Median household income
- $75,672
- Cities and towns
- 2 plus 7 CDPs
- ZIP codes
- 9
- Time zone
- Pacific
- FIPS code
- 06011
Cities and towns in Colusa County
Colusa County has 2 incorporated cities, towns and villages. Populations count the people living inside Colusa County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Colusa (county seat) | City | 6,519 | |
| Williams | City | 5,529 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Arbuckle | 3,093 | |
| Maxwell | 1,245 | |
| College City | 557 | |
| Princeton | 365 | |
| Grimes | 280 | |
| Lodoga | 259 | |
| Stonyford | 111 |
ZIP codes in Colusa County
9 ZIP codes reach into Colusa County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 95645 also Yolo and Sutter counties
- 95912
- 95932
- 95950
- 95955
- 95957 also Sutter County
- 95970 also Glenn County
- 95979
- 95987
Population of Colusa County, 2020–2025
Colusa County grew by 1 people (±0%) between April 2020 and July 2025: 377 more births than deaths and a net loss of 399 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 21,858 |
| 2021 | 21,949 |
| 2022 | 21,927 |
| 2023 | 22,052 |
| 2024 | 22,016 |
| 2025 | 21,836 |
Neighboring counties
- Lake County west · 67,772 people
- Glenn County north · 28,141 people
- Sutter County east · 98,787 people
- Yolo County southeast · 224,410 people
- Butte County northeast · 209,211 people
Printable Colusa 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) (103 KB)
- PNG (2400 px) (73 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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