Sonoma County construction: bids, contractors and projects
Caltrans lettings, licensed contractors and project news for Sonoma County, California, updated daily from public records.
Sonoma County is part of our District 4 (Oakland) coverage area and falls under Caltrans District 4 (Oakland), headquartered in Oakland. CSLB's license file lists 5,130 construction contractors with a Sonoma County address: 2,524 licensed General Engineering (A) and General Building (B) contractors and 2,606 licensed specialty (C) and Residential Remodeling (B-2) contractors. The largest single group is CSLB specialty (C) contractor (2,574). Most are based in Santa Rosa, Petaluma, Sebastopol.
Caltrans's advertised letting schedule currently has 2 upcoming proposals in Sonoma County, the next on Nov 5, 2026.
Upcoming Caltrans lettings in Sonoma County
| Letting | Proposal | Major work type | Documents |
|---|---|---|---|
| Nov 5, 2026 | 04-3Y7104 | Mod Sig & Ltg, Pvmt repair, SW, curb ramp, Segmental Conc Ret System 路 License A,C-10,C-12 | Proposal |
| Nov 18, 2026 | 04-1Q76U4 | Replace bridge, widen Rdwy, railroad, drainage, Elect and landscape 路 License A,C-8,C-12 | Proposal |
Contractors based in Sonoma County
Counts come from the Contractors State License Board's License Master file (businesses whose license status is Clear and whose address is in Sonoma County). Firms holding a General Engineering (A) or General Building (B) classification are counted as general contractors; the rest as specialty contractors.
- CSLB specialty (C) contractor: 2,574
- CSLB General Building (B) contractor: 2,158
- CSLB General Engineering (A) contractor: 366
- CSLB Residential Remodeling (B-2) contractor: 32
Find Sonoma County subcontractors Find Sonoma County general contractors
Sonoma County project news
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How to bid public work in Sonoma County
State highway work in Sonoma County is let by Caltrans; the county is in Caltrans District 4 (Oakland) (Caltrans districts). Bidders need a CSLB license and, for public works, DIR public works contractor registration. See how to bid Caltrans contracts.
State agencies buy through Cal eProcure (see the supplier registration guide).
Statewide rules that apply here
- Bidding Caltrans: a CSLB license, DIR registration, a bidder ID and a digital ID
- California mechanics liens: 20 days to give notice, 90 days to record, 90 days to sue
Nearby counties
District 4 (Oakland) region: Alameda 路 Contra Costa 路 Marin 路 Napa 路 San Francisco 路 San Mateo 路 Santa Clara 路 Solano
Also in Caltrans District 4: (same as above)