Recreation Areas in the National Park Service
Delaware Water Gap National Recreation Area in Pennsylvania and New Jersey was authorized in 1965 to include the proposed Tocks Island Reservoir and scenic lands in the Delaware Valley totaling 71,000 acres. The [National Park] System's first national recreation area east of the Mississippi, it was envisioned to serve 10,000,000 visitors annually from the New York and Philadelphia metropolitan areas. But the Tocks Island Dam came under heavy attack from conservationists and others, especially after the National Environmental Policy Act of 1969 forced greater consideration of the environmental effects of such projects. Without repealing the authorization for the dam. Congress in 1978 ordered the transfer of lands acquired by the Army Corps of Engineers to the [National Park] Service and made the Delaware River within the recreation area a national scenic river-- a designation incompatible with its damming. No other unit of the [National Park] System differs more from its original concept.
from The National Parks: Shaping the System