PORTLAND, Maine -- As a youngster, Mark Warner enjoyed hiking sections of the Appalachian Trail but never gave much thought to the idea of traveling it from end to end.
More recently, however, the 68-year-old retired nature photographer from Newcastle made at least a half-dozen trips along the entire 2,174-mile trail between Georgia and Maine, not on foot but in vintage airplanes he rebuilt himself.
Between those flights and a bunch of shorter ones, he figures that he has logged more than 20,000 miles flying above the trail.
The product of all that travel is showcased in Warner's latest book, ''The Appalachian Trail: An Aerial View," a portfolio of pictures of the trail taken from a vantage point of 500 feet to 2,000 feet above the ground. In addition to the rugged peaks and high ridges the trail is famous for, the photos include lowland meadows, river and highway crossings, and even several towns.
Warner hopes the book will appeal to trail hikers looking for a bird's eye view of the places they've passed.
Warner, who has worked as a wildlife and boating photographer for 30 years, is the author of two books on nature photography. He said he decided to publish his new book himself in order to retain editorial control.
The Appalachian Trail Conference in Harpers Ferry, W.Va., is distributing the book, which spokesman Brian King said is the first such collection of aerial photos he has seen.
The book, sold at trail shops or through the ATC, should appeal to hikers as well as anyone who enjoys landscape photography, King said.
''I think it gives hikers especially a whole different perspective on where they've been and where it fits," he said.
The project is an outgrowth of Warner's renewed interest in flying, a pastime he gave up years ago. In the early 1990s he stumbled upon a 1947 Piper Cub Super Cruiser in Rockland that needed lots of work. ''I made a ridiculously low offer, and they took it," he recalled.
Warner, who was then living in Connecticut, spent three years restoring the antique three-seater with the idea of selling it at a profit. But his plans changed after a dinner guest recounted his adventures hiking the Appalachian Trail and Warner decided to fly over the nearest portion of the trail to get a look at it.
His view of the footbridge across Ten Mile River just upriver from the Housatonic hooked him on the project he would pursue for nearly five years: taking aerial shots of the trail with his 1970s-vintage Nikon F2 camera in all 14 states it passes through and putting the best of the photos in a book.
Warner did his research during the winter, combing through hiking guides and other publications to find suitable spots along the trail to photograph.
To locate a potential site, he would determine its longitude and latitude, then enter the numbers into a hand-held Global Positioning System unit that could steer him to the right place while he was aloft.
Once there, Warner would aim for a shot that would show the trail and perhaps include a shelter, footbridge, or other landmark. He would check the light angles and shadows before spiraling down to get the picture, usually getting what he wanted by the third run.
''I'd circle three or four times, then get the airplane stable to make the photo run and swing the window open and take the picture," he said.
He would hold the stick between his knees to steady the plane as he clicked the shutter.