Twenty-five hundred feet above the Upper Delaware Wild and Scenic Reserve, two young eagles close to within feet of each other, put on the air brakes, and face off. Wings flared, they raise and lock talons. They hold together briefly, beginning a short spiral before they part and return to soaring above their winter feeding waters.

This demonstration of airborne prowess÷a mating ritual called cartwheeling÷had been absent from New York skies for years and, appropriately, the two youngsters staged their show above The Eagle Institute and its volunteers.

In 1970, only one pair of nesting bald eagles remained in all of New York, down from hundreds at the turn of the century. Habitat loss, wanton killing, and the use of DDT had nearly eliminated them.

Then, with the 1976 Endangered Species Act, the New York Department of Environmental Conservation (DEC), under Peter Nye, began restoring the bald eagle. Importing eaglets from as far away as Alaska, the program involved hundreds of personnel and volunteers, including the Audubon Society.

By 1989, theyâd released 198 eagles. By 1996, 29 nesting pairs in New York were producing young. The eagle was back.

Eagles mate for life and use the same nests year after year. When northern waters freeze, pairs from the Adirondacks and Canada fly south to winter along the Upper Delaware. In 1990, the state purchased 12,000 acres, creating the Eagle Preserve.

But man again became a problem. The DEC set up a viewing station, but without supervision, visitors sometimes disturbed the birds. Wintering eagles conserve energy and, aside from flying out to feed, they spend most of their time roosting. People want to see them fly, but eagles are reclusive and quick to feel threatened.

New York resident Lori McKean, an employee of the Pennsylvania Forest Service, saw her first eagle here÷and an idea clicked.

ãI thought, not everyone gets a chance to see this,ä she says. McKean wanted to change that and to foster less intrusive viewing.

The Upper Delaware, the border between New York and Pennsylvania, is an anomaly: The two shorelines where eagles roost are controlled by different wildlife agencies, and the river where they feed is under the National Park Service. And no program educated people about eagles.

ãI felt there was a need for an on-site program,ä McKean says. For six years she collected data÷counts, nest locations, feeding patterns÷for the Audubon Society and recruited volunteers to help visitors enjoy the sites without disturbing the eagles.

When eagles were taken off the endangered list in 1995, the Audubon Society closed its office, and McKean took her program home but couldnât end it. ãThis was something I just couldnât walk away from,ä she says of the year she spent recruiting and organizing volunteers from her home in Highland Lake, N.Y. (pop. 890). She dispatched them to instruct visitors about what McKean calls ãeagle etiquetteä÷avoiding noise, using the observation blinds, and employing binoculars instead of trying to get ãa little bit closer.ä

Five years ago McKean founded The Eagle Institute. Now, from a park service building in Lackawaxen, Pa., she posts volunteers at five sites÷on both sides of the river÷during the watching period. They monitor roosting sites and help ensure minimum intrusion on birds and habitat.

In the 2000 count, 238 eagles wintered in southeast New York, 145 of them along the 73-mile stretch of the Delaware, with 13 breeding pairs. McKean, with a husband, three children, and a full-time job, has seen her mission grow.

ãPeople have said itâs a passion with me,ä she says. ãI guess it is, because I keep doing it.ä