10 May 1984
| 8 ha|
| In the Susquehanna River, Martic Township, Pennsylvania|Duncan Island (36LA60,61) Wikipedia
Duncan Island (36LA60,61) is a prehistoric archaeological site located in the Susquehanna River at Martic Township in Lancaster County, Pennsylvania. It underwent study in the 1950s and 1970s. Artifacts dated to the Archaic period (c. 8000 B.C. to 1000 A.D.) were uncovered.
It was listed on the National Register of Historic Places in 1984.