Porte des Morts, from the French meaning “door of the dead,” is a strait that connects Lake Michigan to Green Bay, Wisconsin. A lighthouse was established in the strait on Plum Island in 1849, later replaced by a lighthouse on Pilot Island.
In 1897 a pair of range lights was established on Plum Island. The rear range lighthouse, a 65-foot-tall skeletal-type tower, remains standing.
Plum and Pilot islands were made part of the Green Bay National Wildlife Refuge in 2007, and Friends of Plum and Pilot Islands was formed to work for the preservation of the historic properties. Mary Beth Volmer is the president of Friends of Plum and Pilot Islands.