Westamerica Bancorporation is a bank holding company. The Company provides a range of banking services to individual and corporate customers in Northern and Central California through its subsidiary bank, Westamerica Bank. The communities served are located in Northern and Central California, from Mendocino, Lake and Nevada Counties in the north to Kern County in the south. It provides a range of loans, including commercial loans, commercial real estate loans, construction loans, residential real estate loans, and consumer installment and other loans. It maintains a securities portfolio consisting of securities issued by the United States Treasury, United States Government sponsored entities, agency and non-agency mortgage backed securities (MBS), non-agency commercial MBS, agency residential collateralized mortgage obligations (CMO), non-agency residential CMO, obligations of states and political subdivisions, asset-backed securities, corporate securities and other securities.