Robert Leggett's eyes dart back and forth between his hand-held stock monitor and his maps and sketches of plans for his recent purchase in northwestern Loudoun County, laid out on his coffee table.

"This is going to be a place for . . . " he begins, but stops in midsentence.

His wife, Dee, picks up his thought: "A place for stewardship, in the biblical sense of the word. It will have aspects of protecting the world, ecology, economic and social values."

Robert Leggett furrows his brow and squeezes his fist as he watches his stock monitor. Forty seconds later, he smiles and lays it beside the sketches so that he can piggyback on his wife's explanation of their plans to preserve a 900-acre tract between Neersville and Loudoun Heights and build a 20,000-square-foot environmental retreat center on part of it.

"My job is to make the money to make things happen," jokes Leggett, 59.

A former advanced air-traffic control designer and math teacher (the U.S. Naval Academy and Loyola College in Baltimore), Leggett devoted himself to being a full-time private investor in 1994 and has been a longtime, active supporter--with time and money--of local and national conservation groups.

Over the last few years, Leggett had been looking for a place he could buy in Virginia or Maryland where he could take his Vienna Boy Scout troop on camping trips, but he couldn't find a prime spot adjacent to the Appalachian Trail. One promising tract turned out to be a prime habitat for rattlesnakes.

Through the Trust for Appalachian Trail Lands, he learned of a property belonging to two sisters and their mother who were considering selling to a residential developer for 200 homes but wished they didn't have to. In June, he closed the deal to pay $2.2 million for the 900-acre tract bounded by Harper's Ferry Road (Route 671) on the east--directly across from the Neersville Volunteer Rescue Company. It is bounded by Sawmill Lane on the south and the Appalachian Trail on the west. On the north it straddles Pinehill Lane.

The purchase was a relief to many in the mostly rural area near the Blue Ridge. To further calm residents about their motivation behind the purchase, the couple presented their plans last month to 200 neighbors and preservationists at the Neersville Fire Hall.

"A man asked me, 'What's in it for you?' " Leggett recalled recently at his home in Great Falls. His eyes darted to the stock screen again before he continued. "I thought, well, nobody's ever asked me that before.

"Clearly we're putting a lot of money into it," he said. "I told him the reason I'm so interested in preserving land in the future is because it's where I'm going to spend the rest of my life. They're not making any more wilderness."

Dee Leggett, 48, a former Army medical specialist, nodded in agreement. "There aren't many places you can find exotic plants and wildlife anymore," she said.

Their plans for the Blue Ridge Center for Environmental Stewardship call for a conference center where conservation and environmental groups can meet and hold training sessions, areas for living history exhibits, a planetarium, hands-on demonstrations of wetlands restoration and forest recovery for school-age children, wildlife restoration projects and butterfly gardens to attract birds.

There also will be an overnight facility for 40 to 70, nature trails--some of which are now horse trails--a library, an amphitheater and an artist or researcher in residence in a studio apartment.

And not to forget the Scouts, there will be outdoor confidence-building courses, pavilions and shelters. To keep it environmentally sound, the Leggetts are working with an architect to maintain as much of the natural surroundings--including fields, forests and wetlands--as possible and operate all buildings on solar and geothermal energy.

He said he plans to have it open by Earth Day 2001.

Leggett said the center will be a good place for environmental groups to work together to rally more private-sector support for their cause, instead of fighting over scarce government dollars.

"They're very competitive over dollars, but they haven't even scratched the surface of what's available in the private sector," Leggett said. He said he envisions the center helping to finance collaborative projects or organizing summits to share ideas.

Preserving the environment is something the Leggetts have long been concerned about. Dee joked that her interest may have been sparked by the Ranger Rick issues she read as a kid. Robert, a former Boy Scout who has been a scoutmaster for 20 years and whose grandfathers were Mississippi farmers, is involved with such groups as the American Hiking Society and Wilderness Society.

Local and national environmental and preservation group leaders said the purchase is a rarity.

The land is "a beautiful mix of open fields, streams and wooded forest in an area that is still mostly rural," said Joe Coleman, president of the Loudoun Wildlife Conservancy. Colemen plans to continue doing butterfly counts on the property. "It's about as natural as you can find in this area. It will save invaluable wildlife habitat along the Blue Ridge."

CAPTION: Robert and Dee Leggett, at their Great Falls property, paid $2.2 million for 900 acres in Loudoun County near Neersville. A family had reluctantly been considering selling the land to a developer.

CAPTION: The Leggetts have grand plans for their environmental retreat, saying "it will have aspects of protecting the world, ecology, economic and social values."