The diverse habitats of Pine Grove Furnace State Park support a variety of wildlife through all seasons. The historic use of the area during the iron furnace period created a varied combination of open areas, wetlands, and vegetation that make the area unique for wildlife.
Spring and fall is the time of bird migrations. The forest, interspersed with ponds and wetlands, makes the park a rest stop for many migrating forest birds. Warblers, vireos, and thrushes stop to rest and eat before flying on to their breeding or winter homes.
Laurel Lake and its shoreline wetlands are a beacon that lures waterfowl. Merganser, Canada goose, mallard, loon, teal, and many other ducks can be seen swimming, diving, and dabbling for vegetation and small fish. Wild turkey and woodcock call from open areas.
Winter is a good time to see woodpeckers and evidence of their presence. Pine Grove Furnace has at least six species of woodpeckers.
Summer is the time of lush green vegetation and growing young animals. In thickets and along roads, watch for spotted fawns and frantic bluebirds searching for food to feed their hungry chicks. Butterflies reach their peak numbers and can be seen floating from flower to flower in the fields and wetlands.
During the fall, the deciduous trees lose their chlorophyll and their leaves reveal beautiful reds, oranges, and yellows. This is a time that many animals are preparing for the winter season ahead. There is a growing population of black bears in the area and visitors may see one putting on weight for the winter hibernation. Beavers may be seen working on lodges and dams in the upper channels of Laurel Lake at twilight.
The Trail of Geology 15 - Pine Grove Furnace State Park Guide (PDF) provides detailed information about the geology of South Mountain.