Island Beach State Park on New Jersey’s Barnegat Peninsula preserves most of the former borough of Island Beach and protects the state’s largest reserve of undeveloped barrier island, among the largest in the United States. Formed after New Jersey bought Henry Phipps Jr.’s 2,694-acre estate in 1953, it includes extensive natural areas and the Sedge Island Marine Conservation Zone of marshes, creeks, ponds, and open water. Its narrow landscape shifts from ocean dunes to a salt- and wind-shaped maritime forest and bayside estuary habitat rich in birds and marine life. The park is valued both for recreation and as a rare surviving barrier-island ecosystem.