Mahopac Bank, Ossining Branch Basic Info Reviews Routing Numbers Map & Direction Name: Mahopac Bank, Ossining Branch Main Office: No Service: Full Service Brick and Mortar Office Location: 2 Church Street Ossining, New York 10562 Westchester County View other branches Phone: 914-923-7659 Please enable JavaScript to view the comments powered by Disqus. Routing NumberProcess ACH TransferProcess Wire Transfer021910836YN021911398YY From: To: