Colusa County is a county in California, United States, in the Sacramento Valley north of the city of Sacramento. It had a population of 21,839 at the 2020 census and covers 1,156 square miles (2,990 km2) centred near 39°11′N 122°14′W.
Colusa is the county seat, and its postal code is 95932. The county has 2 incorporated cities, 7 census-designated places, and a scatter of smaller unincorporated communities, most with no post office of their own. Colusa County sits in the Pacific time zone and carries FIPS code 06011.
Towns & Villages in Colusa County
Only Colusa and Williams are incorporated cities; the rest of the county’s roughly two dozen named places are census-designated places (CDPs) or small unincorporated communities. The table below marks each accordingly.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Colusa | City · seat | 6,143 | 95932 |
| Williams | City | 5,246 | 95987 |
| Arbuckle | CDP | 2,895 | 95912 |
| Maxwell | CDP | 1,164 | 95955 |
| Grimes | CDP | 363 | 95950 |
| Princeton | CDP | 328 | 95970 |
| College City | CDP | 284 | — |
| Stonyford | CDP | 209 | 95979 |
| Lodoga | CDP | — | — |
| Colusa Rancheria | Unincorp. | — | — |
| Sites | Unincorp. | — | — |
| Grand Island | Unincorp. | — | — |
| Delevan | Unincorp. | — | — |
| Leesville | Unincorp. | — | — |
| Wilbur Springs | Unincorp. | — | — |
| Fouts Springs | Unincorp. | — | — |
| Genevra | Unincorp. | — | — |
| Cortena | Unincorp. | — | — |
| Sycamore | Unincorp. | — | — |
| West Butte | Unincorp. | — | — |
| Devils Elbow | Unincorp. | — | — |
| Harrington | Unincorp. | — | — |
| Boyers Landing | Unincorp. | — | — |
| Fraziers Landing | Unincorp. | — | — |
| Millers Landing | Unincorp. | — | — |
| Mills Orchards | Unincorp. | — | — |
| Bonnie View | Unincorp. | — | — |
| Arbee | Unincorp. | — | — |
| Delphos | Unincorp. | — | — |
| Stegeman | Unincorp. | — | — |
| Graino | Unincorp. | — | — |
Colusa Rancheria is a federally recognized Cherokee‑affiliated Cachil DeHe Wintun tribal land base near Colusa, not a general-purpose town. Grand Island, Boyers Landing, Fraziers Landing and Millers Landing are Sacramento River landings rather than settlements with a resident population count of their own.
ZIP Codes
- 95932 — Colusa
- 95987 — Williams
- 95912 — Arbuckle (also serves College City)
- 95955 — Maxwell
- 95950 — Grimes
- 95970 — Princeton
- 95979 — Stonyford
Lodoga and the county’s rural landings and ranch communities are served by the ZIP code of the nearest post office town rather than having one of their own.
Geography
Colusa County spans the flat floor of the Sacramento Valley in its east and rises into the inner Coast Range foothills toward the west, where Fouts Springs and Wilbur Springs sit in rugged, sparsely populated terrain. The Sacramento River runs along the county’s eastern edge, and the Sutter Buttes are visible on the horizon to the southeast, though the buttes themselves lie across the line in Sutter County. Bear Creek and Stony Creek are the county’s main interior waterways.
Colusa County borders Glenn County to the north, Butte County to the northeast, Sutter County to the east, Yolo County to the south, and Lake County to the west.
Demographics
The 2020 census counted 21,839 residents, giving the county a density of roughly 19 people per square mile. Colusa and Williams are by far the largest communities, together accounting for more than half the county’s population. Median household income runs well below the California median of $95,521, reflecting the county’s dependence on seasonal agricultural work.
Economy & Local Life
Agriculture dominates Colusa County’s economy: rice, almonds, tomatoes, walnuts and prunes are the leading crops, and the flat valley floor east of Interstate 5 is planted almost entirely to irrigated row and orchard crops. Colusa Regional Medical Center and the county government are among the largest employers in the county seat. The Colusa County Fair, held each May in Colusa, is the county’s biggest annual event.
History
Colusa County was organized on February 18, 1850, as one of California’s original 27 counties. Its name derives from a Patwin village name recorded by early settlers as “Ko‑roo” or “Korusi,” later anglicized to Colusa. The county originally covered a much larger area of the northern Sacramento Valley before Glenn County split off in 1891.
Getting There
Interstate 5 crosses the eastern side of the county on a north‑south line, with State Routes 20, 45 and 16 providing the main east‑west and river‑valley connections.
- Sacramento — 60 miles south
- Chico — 40 miles north
- Yuba City — 25 miles east
- Woodland — 35 miles south
The nearest commercial airport is Sacramento International Airport.
Frequently Asked Questions
Where is Colusa County?
It is in California’s Sacramento Valley, north of Sacramento and east of the Coast Range, bordering Glenn, Butte, Sutter, Yolo and Lake counties.
What is the population of Colusa County?
21,839 people, per the 2020 census.
How big is Colusa County?
1,156 square miles (2,990 km2).
What is the county seat of Colusa County?
Colusa is the county seat.
How many towns are in Colusa County?
Two incorporated cities, Colusa and Williams, plus seven census-designated places and a number of smaller unincorporated communities.
What ZIP codes are in Colusa County?
The main ZIP codes are 95932 (Colusa), 95987 (Williams), 95912 (Arbuckle), 95955 (Maxwell), 95950 (Grimes), 95970 (Princeton) and 95979 (Stonyford).
What crops does Colusa County grow?
Rice, almonds, tomatoes, walnuts and prunes are the county’s leading agricultural products.
More counties in this state: Towns and villages in California.