THE COLUSA COUNTY LAND BRIEF
Land in the
Butte Sink/Sutter and Colusa Basins setting.
Colusa County has 1,150.6 square miles of land in California. 8 mapped landscape regions meet across Colusa County: Butte Sink/Sutter and Colusa Basins, Foothill Ridges and Valleys, Yolo Alluvial Fans, among others.
The Sacramento and San Joaquin river systems occupy broad sediment-filled basins, with fans and terraces toward the valley margins. These nearly level landscapes contrast with California's surrounding hills and mountains.
Regional context: Central California Valley ↗ · Regional mapping across the county footprint
Where the landscape changes
Colusa County intersects 8 mapped regional units. The largest mapped shares are:
- Butte Sink/Sutter and Colusa Basins33.6%
- Foothill Ridges and Valleys23.7%
- Yolo Alluvial Fans12.5%
- Western Valley Foothills/Dunnigan Hills10.4%
- North Coast Range Eastern Slopes8.7%
Central California Foothills and Coastal Mountains in Colusa County
Oak woodland, chaparral and grassland occupy foothills and low coastal mountains around the Central Valley. Narrow agricultural valleys interrupt this landscape of dry summers and wetter winters.
Read the regional source ↗Klamath Mountains/California High North Coast Range in Colusa County
Dissected ridges, valleys and foothills combine varied rock types with diverse conifer and hardwood forests. The Klamath and Siskiyou ranges differ geologically from the volcanic Cascades to the east.
Read the regional source ↗Finding your parcel within Colusa County
The atlas lists 9 cities, towns, townships, and Census communities associated with Colusa County, including Williams, Colusa, Lodoga. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Colusa County by land and water
The Census records 5.7 square miles of water within Colusa County, or 0.5% of its total area. That share is close to Colusa County’s 0.5%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Colusa County has 232.6 times the land area of nearby Williams city (4.95 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Butte County, Glenn County, Lake County, Sutter County, Yolo County within California. A tract near one of these lines should be matched to the county identifier on its own records.

