Even before Mission 66 was completed, individuals had emerged to influence the shape of the NPS. In 1963, a committee of distinguished scientists issued a report focusing on the management of natural areas. They declared that the nation's parks "should represent a vignette of primitive America."
Environmentalists also voiced their opinions through literature. One such was Edward Abbey's Desert Solitaire, an account of the author's experiences as a ranger at Arches National Park. On the national front, Rachel Carson's Silent Spring first alerted the public to the damage that certain pesticides, such as DDT, were causing to wildlife.
A series of congressional acts passed over the next few years—including the Wilderness Act of 1964, the National Historic Preservation Act of 1966, and the National Environmental Policy Act of 1969—reflects the growing concern for protection and conservation.
The National Historic Preservation Act was particularly significant for the NPS because it authorized the National Register of Historic Places. The National Register, which is administered by the NPS, is a list of historic and archeological resources that have been designated for preservation. It includes national historic landmarks, all historic areas in the national park system, and properties all over the country that are significant to a particular community, a state, or the nation as a whole.
Congress Defines the National Park System
In 1970, the General Authorities Act was passed. This piece of legislation stated that the various areas managed by the NPS—like parkways, recreation areas, and national seashores— all had equal standing in the park system.
The NPS's role in managing these areas was further clarified in the Redwood National Park Expansion Act of 1978, which stated that the NPS cannot allow activities that violate a park's enabling legislation—the law that created the park and outlined its purpose.
Sparked by a heightened interest in environmental protection and the approaching American Bicentennial, the NPS expanded considerably during this era, particularly under Director George Hartzog.
Director Hartzog and Secretary Udall
George Hartzog, (Director, from 1964 to 1972) was a dynamic, politically astute manager, who added some 70 new areas to the national park system during his tenure. He also greatly enlarged the Service's role in urban recreation, historic preservation, interpretation, and environmental education.
This era under Secretary Stewart Udall (from 1961 to 1969) saw the establishment of major new national policies that affected the National Park Service: the Wild and Scenic Rivers Act, The Endangered Species Preservation Act and the National Trail System Act.