The Great Swamp National Wildlife Refuge Wilderness now contains a total of 3,660 acres and is managed by the Fish & Wildlife Service's Great Swamp National Wildlife Refuge . All of the Wilderness is in the state of New Jersey. In 1968 the Great Swamp National Wildlife Refuge Wilderness became part of the now over 110 million acre National Wilderness Preservation System. Roughly 25,000 years ago, where the Wisconsin Glacier reached its furthest point south and stopped, the creation of Great Swamp began. With cattail marshes, wet meadows, swamp woodlands, and ridges thick with oak, beech, and laurel, Great Swamp provides a home for 39 species of mammals including mice, moles, skunks, raccoons, otters, foxes, white-tailed deer, and the endangered Indiana bat. Migratory birds see Great Swamp as a "nest and rest" (244 species have been identified). Numerous reptiles and amphibians have taken up residence, including rare bog turtles, wood turtles, and blue-spotted salamanders. The Great Swamp National Wildlife Refuge was established in 1960 following grassroots action to save the area from being developed into a major metropolitan airport. In 1968, the eastern half of the Refuge was designated as the very first Wilderness Area within the Department of the Interior. About 8.5 miles of primitive trails provide access during daylight hours only, and camping and picnicking are not permitted.