Westamerica Bank, Sonoma Basic Info Reviews Routing Numbers Map & Direction Name: Westamerica Bank, Sonoma Main Office: No Service: Full Service Brick and Mortar Office Location: 18615 Sonoma Highway, Suite 108 Sonoma, California 95476 Sonoma County View other branches Phone: 707-939-7300 Please enable JavaScript to view the comments powered by Disqus. Routing NumberProcess ACH TransferProcess Wire Transfer121137001YN121140218YY121141000YN121141615YN From: To:
