The John Heinz NWR at Tinicum is located in Philadelphia and Delaware Counties, Pennsylvania about 1 mile from Philadelphia International Airport. The refuge was established by an act of Congress in 1972 to protect the largest remaining freshwater tidal marsh in Pennsylvania; approximately 200 acres. When acquisition is complete, it will consist of 1200 acres of varied habitats. Over the years, the refuge has become a resting and feeding area for more than 300 species of birds, 85 of which nest here. Fox, deer, muskrat, turtles, fish, frogs and a wide variety of wildflowers and plants are among the species that call the refuge "home". The Congressional mandate set forth for the refuge was to protect, preserve and enhance habitat; provide compatible outdoor recreation opportunities for the public; and to promote environmental education.