The Canfield Island Site, also known as Archeological Site 36LY37, is an archaeological site in Lycoming County, Pennsylvania, United States. Located on Canfield Island in the West Branch Susquehanna River,[2]:7 the site lies east of the city of Williamsport in Loyalsock Township.[3] It is believed to have been inhabited by prehistoric Native Americans for thousands of years, with the oldest discoveries dating back to more than one millennium before Christ.