With habitats ranging from rivers and ponds to dry ridge tops, the recreation area is home to a variety of animals, from black bears weighing up to 800 pounds to ruby-throated hummingbirds, only 3-4 inches long.
The Delaware River and its tributaries support more than 60 fish species, including species that make the park their permanent home and migratory species such as eels and American shad that travel between the upper reaches of the river and the Atlantic Ocean. Great blue and green-backed herons wade in shallows looking for fish, frogs, and crustaceans for a meal. Otters glide silently through the water. On the river's floodplain, rich soil supports bountiful farm fields.
Visitors can commonly see white-tailed deer and wild turkey searching for food. After nightfall, the park comes alive with a whole new set of animals: foxes, coyotes, bobcats, raccoons, and, in the night sky, owls, and six species of bats.