Westamerica Bank, Clearlake Branch Basic Info Reviews Routing Numbers Map & Direction Name: Westamerica Bank, Clearlake Branch Main Office: No Service: Full Service Brick and Mortar Office Location: 15342 Lakeshore Drive Clearlake, California 95422 Lake County View other branches Phone: 707-995-4140 Please enable JavaScript to view the comments powered by Disqus. Routing NumberProcess ACH TransferProcess Wire Transfer121137001YN121140218YY121141000YN121141615YN From: To: