For sale: 1725 farmhouse on 40 acres in heart of eastern Prince William County. Four BR, seven stone fpl., fully furn. w/ 18th cent. antiques. Mint condition. Spectacular Potomac Riv Vue. George Washington slept here.

For just $1.6 million, it can be your piece of paradise nestled in the sprawl of suburbia.

Rippon Lodge, the oldest Colonial house still standing along the Potomac River, is for sale. Set high on a bluff amid lofty oaks in Woodbridge, halfway between Washington and Fredericksburg, the two-story clapboard house has survived for 275 years, eluding damage from war and, even more miraculously, escaping the fires that destroyed all but a handful of its contemporaries on the James and Potomac rivers.

Since the late 19th century, many of the plantations of Virginia's first families have been restored by preservationists and opened to the public, but Rippon has remained remote and inaccessible--held almost continuously by heirs of architect Richard Blackburn, who built the estate before he is said to have designed Washington's at Mount Vernon, about 12 miles away.

Now, with the house for sale, many preservationists, historians and local officials had hoped to find a way for the county or perhaps a foundation to buy it and turn the estate into a tourist attraction and community asset. So far, the sole attempt to buy Rippon and make it available for public use has failed for lack of money and, some say, because Prince William lacks the enthusiasm for preservation seen in other parts of Northern Virginia.

An easement will protect the property from the bulldozers. But preservationists and local officials fear that the county has lost a rare chance to lay hands on one of the last pieces of its early history left along the Potomac.

"It's a tremendous lost opportunity," said Sean Connaughton, Prince William's new county board chairman. "We're seeing a major site go out of our hands. We're losing our history."

The county is taking stabs at preservation, restoring a 19th-century village in Brentsville and rebuilding an old mill destroyed by fire last year. But major preservation projects--as Rippon Lodge would be--require a sense of place that is elusive in a land of new subdivisions and transient residents, historians complain.

"There are very few native Prince William people you can get interested in history, and this is a transitory place," said Brad Hedrick, a former president of Historic Prince William, a nonprofit group whose meetings have dwindled to just four times a year. "That's why the county has zilch."

Blackburn was a Yorkshireman who farmed tobacco and cotton on Rippon's 21,000 acres, which he acquired from Lord Fairfax in 1725. George and Martha Washington were often guests of Blackburn's son, Col. Thomas Blackburn, who served as Washington's aide-de-camp during the Revolutionary War. About 30 years after Rippon was built, Richard Blackburn helped design Mount Vernon, adding another gem to the shoreline, which also included patriot George Mason's estate, Gunston Hall, at Lorton.

When rumors of Rippon's sale hit last fall, county officials applied for a $440,000 grant from the Virginia Land Conservation Foundation to help buy the property. They hoped to boost tourism by converting the estate to a museum or conference center, but the application was turned down, in part because easements protect Rippon and its 40 acres from destruction, according to foundation officials.

"It couldn't be ranked highly as a threatened property," said Kathleen Kilpatrick, deputy director of the Virginia Department of Historic Resources.

County officials said they doubt they'll find other resources to bid again. Their offer was substantially less than the current asking price of owner Debra Black Decko, 50, a descendant of Blackburn whose father, Antarctic explorer Richard Blackburn Black, brought Rippon back into the family in 1952. Decko grew up in the house. Prince William's foundering historic preservation community, with no formal fund-raising organization, says it cannot find the money to buy Rippon Lodge.

"It's a terrible disappointment to all of us," said Betty Duley, president of the county's historic commission, an advisory board that does not raise money. "It's one of the most beautiful sites we had left in the county."

It's a county that has seen much of its 360 square miles paved over and built upon as the Washington suburbs have pushed outward. All but 40 of Rippon's original 21,000 acres have been carved into the roads, town house developments, strip malls and gas stations that define Prince William's eastern end. Amid the sprawl, Rippon stands as an architectural treasure, say historians. Its uneven pine floorboards are held together by tree nails and its foundation is still supported by the trunks of locust trees. Crystal chandeliers, trundle beds, Chippendale chairs and an 18th-century wig stand are among the antiques in its 17 rooms. The dining room and parlor--the latter the scene of two legendary 18th-century duels--are paneled in ruby-red pine so rare that Colonial Williamsburg tried to buy it in the early 1920s. The owners refused.

Today, Decko, a District resident, says she finds herself burdened by taxes and upkeep costs. So she has listed the 4,075-square-foot house, barn, caretaker's cottage, three-car garage and two guest cabins with an Alexandria real estate agent and Christie's estates division.

"I hate to sell it," she said. "I feel I've been very fortunate to grow up here, but it's time for somebody else to take it over now. A lot of people in Woodbridge don't even know it's still here."

Some local historians wonder if the region's fascination with the Civil War might make a Colonial-era home more of a challenge to preserve. "The interest is out there, but it has to be cultivated, since less is known about the Colonial period," said Don Wilson, chief of the Bull Run Regional Library's Virginia collection.

Rippon is also burdened by its location--a stone's throw from the Route 1 strip with its fast-food restaurants, strip malls and gas stations.

"One of the biggest threats we have [to interest in historic homes] in Northern Virginia is that a lot of sites are little islands in the midst of sprawl," said Lisa Burcham, a senior official with the Virginia Office of the National Trust for Historic Preservation, which owns just four homes in the state. "People don't like to visit places they feel are uncomfortably cut off from the feeling a historic site would evoke. It can ruin the expectations you have."

CAPTION: Rippon Lodge, in Prince William County, is the oldest Colonial-era house along the Potomac River.

CAPTION: Debra Black Decko and husband Charles Decko are asking $1.6 million for the Colonial-era estate.

CAPTION: The mansion, built in 1725 on 21,000 acres, boasts an ivy-bordered underground entrance leading to the basement.