Plum Island was the original location of the Port des Morts (Death’s Door) light before it was relocated to Pilot Island in 1858. A stone tower, dwelling and light were put into operation in 1849, but it was determined the light was located too far within the passage, so a light was built on Pilot Island to the southeast. In 1895 funds were appropriated to build a station on the northeast side of the island. The white tower often seen by ferry passengers is the rear range light of the Plum Island Range Lights.
The lighthouse is now owned by the U.S. Fish and Wildlife Service, and the grounds and tower are not open to the public. The Plum Island Rear Range Lighthouse can best be seen from the Northport-Washington Island Ferry or the excursions that pass by the island during the annual Lighthouse Festival the second weekend of June.