First Security Bank and Trust Company, Thornton Branch Basic Info Reviews Routing Numbers Map & Direction Name: First Security Bank and Trust Company, Thornton Branch Main Office: No Service: Full Service Brick and Mortar Office Location: 308 Main Street Thornton, Iowa 50479 Cerro Gordo County View other branches Phone: 641-998-2312 Please enable JavaScript to view the comments powered by Disqus. Routing NumberProcess ACH TransferProcess Wire Transfer073901592YY073903312YN From: To: