Fauquier County lies west of Washington in the rolling hills of the Virginia piedmont and, like its neighbor Loudoun County, is sparsely settled and primarily agricultural.

But like its other neighbor, Prince William County, Fauquier lies on the commuter route of I-66, and county officials are growing increasingly wary of the potential development pressure I-66 could bring to this rural county in the next two decades.

"I-66 has not had a significant impact yet on growth in the county," said Richard McNear, county director for planning and zoning. "But the trend is in that direction, and we are already feeling some small-lot development pressures east of Warrenton."

In an effort to head off some of that pressure, particularly in the county's agricultural areas, the Fauquier County Board of Supervisors approved a massive downzoning plan two years ago that changed all agricultural land from one house per two acres to one house per five acres. They also changed the zoning on nearly 500 acres of commercially zoned land to residential.

Typical for Virginia, that downzoning has been challenged in court by a landowner contesting the legality of having her 22 acres of commercial land rezoned to residential. But Fauquier County officials said that the circuit court issued a ruling six weeks ago confirming the legality of the board's downzoning. McNear said no other land-use suits are pending against the county.

According to area real estate agents and developers, the majority of the development in the county has been limited to the Rte. 29-211 corridor, a wide belt of land along the four-lane divided highway that connects Warrenton, the county seat, with I-66 in Prince William County.

"That's the only place you can develop anymore," developer David Finchum said. "It's the only place where there's land zoned R1 one house per acre . And if you're not zoned R1 in this county, you're in trouble."

Finchum said that the land closer to I-66, where it crosses the northern section of Fauquier, is either agricultural or conservation land and that the development potential there is severely limited.

McNear said that the county zoning ordinance also was changed at the time of the downzoning to allow only land zoned for agricultural or conservation use to be subdivided into three parts, no matter the size of the original parcel. To subdivide a parcel into more units, the landowner must petition the Board of Supervisors for a special exception.

"That process means we can further restrict the pace of growth, and encourage clusters, where some of the land is left as permanent open space," said McNear.

Some Fauquier developers actually consider the land adjacent to I-66 less desirable than the land in the 29-211 corridor.

"We're closer to DC here east of Warrenton and there's shopping nearby and the county seat," said developer Peter Snyder, a local builder working on a 70-house subdivision called Warrenton Village. "This is still where everything is happening."

One real estate agent, who asked not to be named, said he believes that Fauquier County officials are trying to keep the county from becoming an extension of the development sprawl creeping westward from Fairfax and Prince William counties.

"Most people here don't want to invite it development , and the county won't volunteer to invite it," the Realtor said. "Everybody who comes out here comes for the lower tax rate and the rural life. They don't want to have to pay for lots of new schools and sewers." Fauquier's tax rate is only one-third the tax rate in Prince William County.

McNear agreed, saying that many of the people who move west from the city into Fauquier County are looking for a hilltop with a view. "Then after a while, everybody is sitting around on their hilltops looking at each other," he explained.