Has Loudoun County stolen the National Air and Space Museum's outpost in Northern Virginia?

Loudoun's visitors Web site proclaims the county the "Home of America's newest Air and Space Museum," along with the rolling hills, horses, wineries and historic towns that are its better-known draws.

But truth be told, the Steven F. Udvar-Hazy Center off Route 28 at Dulles International Airport sits squarely in Fairfax County, on 176 acres in Chantilly. And Fairfax supervisors are incensed that their neighbor to the west would even think of taking away the county's bragging rights to the region's newest tourism jewel, which will celebrate its first anniversary next month.

Board Chairman Gerald E. Connolly (D) brought up the offending claim at the supervisors meeting Monday, quickly eliciting a chorus of indignant comments from his colleagues. He then demanded that their Loudoun counterparts correct the error.

"We need a section of our Web page entitled, 'Liar, liar, pants on fire!' " Connolly joked.

Supervisor Gerald W. Hyland (D-Mount Vernon) said he was mistaken to have thought "the Cold War was over." Supervisor Michael R. Frey (R-Sully), whose district includes the museum, called on Loudoun to fix the "geographic misimpression."

But tourism officials in Loudoun, which claims the 10,000-acre Dulles International Airport with Fairfax, yesterday took umbrage at Fairfax's demand, defending the Web site as legitimate marketing to promote the museum and the fast-growing county. And no, they have no intention of removing the reference.

Geography, it seems, is malleable in the marketing world.

"That's our positioning statement based on market research, based on what visitors think they're coming to our area to experience," said Cheryl Kilday, president and chief executive officer of the Loudoun County Convention and Visitors Association. "It's a hook." She said tourists "don't understand borders or county lines."

"It makes a lot of sense to have the museum in Loudoun, even though it's across the county line," Kilday added.

Museum spokesman Frank McNally acknowledged that Chantilly does not usually come up when staff members give visitors directions. "If you say to the traveling public, it's near Dulles, that's one thing, but if you say Chantilly, oh, do they understand Chantilly?" he said. Either way, "it's nice to be fought over."

Arnie Quirion, president of Fairfax County's new tourism bureau, said he understands Loudoun's need to "be perceived as being in the middle of where things are happening" and admires the county's "aggressiveness in wanting to get all they can" from the museum's close proximity to the county.

"But we're obviously going to claim that mantle" of its location, he said.

Some Loudoun supervisors suggested that their much bigger neighbor hold its tongue.

Supervisor Bruce E. Tulloch (R-Potomac) added that there's no reason for Fairfax officials to be "sticking their hand in the air saying, 'Mine, mine, all mine!'

"With all due respect to Chairman Connolly, last time I looked," the museum was a regional asset, Tulloch said. "I don't think we need a scorecard for what's in what county."

Staff reporter Michael Laris contributed to this report.