Sonoma County, California, a core county of the Santa Rosa-Petaluma, CA market, holds $19.7B in deposits across 14 insured institutions and 92 branches. Wells Fargo Bank is the largest deposit holder at 24.5% share. The top three banks hold 56% of deposits, which places the county in the Moderate band. Deposits have grown 6.3% since 2021 while the branch count fell by 15.6%. It produced $30.9B of real gross domestic product in 2024, ranking #153 of the 1,523 ranked counties by economic output.
Ranks show where the county stands among the 1,523 ranked counties (those within a Combined or Metropolitan Statistical Area that have a branch). They describe relative position, not a rating of market quality or suitability.
Deposit trend
Branches: 109 in 2021 to 92 in 2026. Institutions: 18 to 14. Top-three share: 52% to 56%.
Institutions by deposits
| Institution | Deposits | Share | 5‑yr deposits |
|---|---|---|---|
| Wells Fargo Bank | $4.8B | 24.5% | +16% |
| Poppy Bank | $3.5B | 17.8% | +134% |
| Exchange Bank | $2.7B | 13.8% | -10% |
| JPMorgan Chase Bank | $2.3B | 11.8% | -5% |
| Bank of America | $2.0B | 9.9% | -20% |
| WaFd Bank | $1.1B | 5.6% | 0% |
| Summit State Bank | $846M | 4.3% | +11% |
| Westamerica Bank | $651M | 3.3% | -21% |
| BMO Bank | $528M | 2.7% | -32% |
| U.S. Bank | $398M | 2.0% | +1% |
| Columbia Bank | $372M | 1.9% | -35% |
| Bank of Marin | $355M | 1.8% | -9% |
| Mechanics Bank | $71M | 0.4% | +17% |
| Tri Counties Bank | $36M | 0.2% | -12% |
The 14 insured institutions with a branch presence in this county, per the FDIC Summary of Deposits, June 30, 2026. Five-year change compares the same institution’s county deposits in 2021 and 2026. Institutions are tracked by FDIC certificate number, and where an institution acquired another bank, the acquired bank’s prior deposits are folded into the baseline so the change reflects the combined, continuing franchise rather than reading as new. “No 2021 presence” means neither the institution nor a bank it later absorbed reported deposits in this county that year. Deposit figures are nominal and are not adjusted for inflation.
Part of the Santa Rosa-Petaluma market
Sonoma County is the only county in the Santa Rosa-Petaluma, CA market, a Metropolitan Statistical Area (ranked #95 of 293 U.S. markets by economic output). It produces 100.0% of the market’s output and holds 100.0% of its deposits.
| Measure | Sonoma County | Share of parent market |
|---|---|---|
| 2024 GDP | $30.9B | 100.0% |
| Deposits | $19.7B | 100.0% |
| Population | 486,444 | 100.0% |
View the full Santa Rosa-Petaluma market profile →
Recruiting in Sonoma County
Deposits are split among a moderate number of institutions. Who holds the deposits, and how contested the market is, shapes both the runway for growth and the competition you would be recruiting against. We recruit commercial relationship managers, banking teams, and market leaders for banks building in markets like Sonoma County.
See how we help banks recruit commercial banking talent