Mountain One Bank Address: 296 Main St, Williamstown, MA 01267 Phone: (413) 458-9503 Hours: Mon: 9am-5pm Tue: 9am-5pm Wed: 9am-5pm Thu: 9am-5pm Fri: 9am-5pm Banks, Loans Other Businesses: Adams Community Bank at 273 Main St, Williamstown, MA 01267 True North Insurance Agency at 795 Main St, Williamstown, MA 01267 TD Bank at 57 Spring St, Williamstown, MA 01267 West's Wine & Spirits at 52 Spring St, Williamstown, MA 01267