Westamerica Bank, Cross Roads Branch Basic Info Reviews Routing Numbers Map & Direction Name: Westamerica Bank, Cross Roads Branch Main Office: No Service: Full Service Brick and Mortar Office Location: 2498 Guerneville Road Santa Rosa, California 95403 Sonoma County View other branches Phone: 707-576-3694 Please enable JavaScript to view the comments powered by Disqus. Routing NumberProcess ACH TransferProcess Wire Transfer121137001YN121140218YY121141000YN121141615YN From: To: