Conservationists have saved from sprawl 255 acres of woodland in western Loudoun County adjoining the Appalachian Trail. The Appalachian Trail Conference, a nonprofit that maintains the trail, bought the property for $1.2 million from Carleton Penn, a former Loudoun County Circuit Court judge, who owned it for four decades.

Penn used the property only for recreation, so it never interfered with the trail, and the conference wants to keep it that way. The property hugs almost two miles of the 2,172-mile trail as it passes from Shenandoah National Park to Harper's Ferry.

"It's a narrow, skinny park," said Bob Williams, director of the conference's land trust programs. The trail averages only about 1,000 feet in width, and the purchase is part of the conference's effort to protect its "viewscape" by buying surrounding land or convincing others to buy it.

In this case, it is seeking five buyers for pieces of the property and has found four.

"We would like to preserve the sense of solitude that the trail has now," Williams said.

First proposed in 1921, the trail stretches from Georgia to Maine. The National Park Service delegates its upkeep to the conference, which is headquartered next door to Loudoun in Harper's Ferry, near the trail's halfway point. The conference estimates that 3 million to 4 million people hike on stretches of the trail every year, and it has recorded 7,183 people who have hiked its entire length.

Since closing on the Penn property at the end of February, the conference has obtained commitments from four buyers and is searching for one more to buy parcels of the Penn property and build one small home each, with conservation easements prohibiting further development.

"We will sell the property to them at essentially the same value we paid for it, which we have reason to believe is less than current market value," conference executive director David Startzell said, noting that buyers would agree to limit development in exchange for the price break. "From our perspective, that's much better than a 200-unit subdivision, which is not unheard of in this area."

Washington lawyer Eric DeSilva has agreed to buy 120 acres of the Penn tract for about $600,000. He calls it "an absolutely beautiful piece of property" and said the easement clinched the deal.

"My whole goal is having a piece of property and a house where it's isolated and out in nature," he said. "What I'm giving up the right to develop is something that I don't want to develop anyway."

The easement comes with a significant tax break. The easement's value, determined by the difference between the value of the undeveloped property and its value if developed, is tax deductible. Encroaching development makes open land in western Loudoun precious, and increasingly, Williams said, suburban development in the mid-Atlantic states, especially around large urban areas such as Washington and Baltimore, is closing in on the trail.

The conference has tried to protect land by buying it and adding it to the park or finding one conservation-minded buyer willing to pay for an entire tract the size of the Penn property or larger.

But the recent economic downturn meant that the conference received less money from donors and could not find one buyer. The group decided that some small houses would be preferable to leaving the land on the market, so it made the purchase and is pursuing subdivision into five smaller parcels.

While planning and saving for his dream house in the woods, DeSilva plans to use the land for a natural escape from his home in Old Town Alexandria. He's not a hiker, although he backpacked on the Appalachian Trail with his father as a boy, and he is an avid rock climber who looks forward to having a home base close to prime climbing sites on the trail.

"I tend to believe that there are lots and lots of people in Washington who could do this," he said. "When you're buying undeveloped land, it doesn't have to be hugely expensive. With these easements there's great tax benefits to do this."

DeSilva contacted the Potomac Appalachian Trail Conference, which maintains a list of people interested in buying conservation property, and was put in touch with the main group. Since the land trust arm of the conference was founded in 1982, it has protected 22,867 acres along the trail through various means, Williams said.

The conference owns Bear's Den, the popular 77-acre retreat and hiker hostel that straddles the line between Loudoun and Clark counties. In 1999, the conference put the Blue Ridge Center for Environmental Stewardship in contact with the owners of 900 acres near the trail, which the center purchased for about $2 million. The center manages Bear's Den for the conference.

A sign marks the 2,172-mile Appalachian Trail as it crosses Route 9 at the Virginia state line. A hiker passes Bear's Den, a retreat and hostel owned by the Appalachian Trail Conference.