The Mount Pleasant activists were delighted after they peppered their front yards with green and white signs reading: "Repair Klingle Road!" But days later, they awoke to find the signs defaced by large white stickers bearing a sarcastic message: "Pave It." In smaller type, the vandals compared the activists to Hezbollah and Islamic Jihad.

"Totally obscene," spewed Gabe Fineman, who lives on nearby Porter Street NW.

He and his neighbors immediately suspected competing activists based in Woodley Park, who would rather the road stay closed to preserve green space.

The Woodley contingent suggested that the Mount Pleasant group had vandalized its own signs. "There's an equal probability that they did it themselves to generate sympathy," argued Ralph Scott, who wants to shut down the road.

It was another pair of strikes in an escalating neighborhood fight over whether to repair and reopen a tattered half-mile stretch of public road that runs through Rock Creek Park or turn it into a recreational path.

If these antics sound ridiculous, they have become almost ordinary in the 12-year history of one of Northwest Washington's longest-running neighborhood feuds.

Residents based mostly east of Rock Creek are pushing a plan to spend an estimated $5 million to repair and reopen Klingle Road, which was shut down after it flooded in 1991 and the city lacked money to repair it. They say it would relieve traffic congestion on nearby streets and provide a convenient shortcut across town.

Their opponents, based largely west of the park, support Mayor Anthony A. Williams's plan to spend about $1 million to convert Klingle into a recreational path. This would save green space and money.

The battle features the weapons of the upper middle class: warring Web sites, in-your-face bumper stickers on BMWs and minivans, expensive official studies and political arm-twisting.

"Neighborhood disputes are the worst, because people don't know how to compromise or negotiate," observed Jack McKay, a Mount Pleasant resident. "They make it personal."

Yesterday at the John A. Wilson Building downtown, more than 100 residents spoke at a public hearing on the competing Klingle bills before the D.C. Council. Both camps wore pins and stickers and came armed with large maps, charts and even aerial photographs. The 13-member council, which is closely divided, likely will vote on the matter within two months.

"The other side has cowed people into being fearful of talking about why they support opening the road, but they can't shut us up," said Paul McKenzie, who works for the Department of Defense and lives east of Rock Creek in Shepherd Park.

But activists who want to close Klingle say the true bullies are the "roadies," as they call their opponents: Who else would have heckled a 9-year-old boy as he pleaded to keep the road closed during a January public hearing at Adas Israel Synagogue in Cleveland Park?

"They play really dirty in lots of instances," said Sheila Hogan, an environmental consultant in Woodley Park. "There are people and businesses on their Web site that have asked them to take their names off because they were lied to and don't support their cause."

Jim Dougherty, the Sierra Club's legal director and a leading voice to keep Klingle Road closed, threatened to sue the Mount Pleasant group after its leaders said the Sierra Club had endorsed the group. "They approach it with a zeal that is grounded more in emotion and philosophy than in facts and reason," Dougherty said.

Over-the-top theatrics have become common. Advocates of keeping the road closed have dressed as trees to highlight conservation issues. Activists who want the road reopened erected a wooden placard that called their opponents "racist plutocrats."

Overtones of race and social class have fed the passion. Although both camps claim supporters on both sides of Rock Creek Park, some eastside residents contend that richer residents in the west have used their political clout to keep the road closed -- and shut out less wealthy residents.

"It goes way back in history to when Rock Creek was a divide between the haves and have-nots," said Laurie Collins, a technology consultant who, along with husband Peter McGee, a lawyer, lives in a Mount Pleasant rowhouse and drives a BMW. "The people who will benefit from this road closure are the wealthy in Woodley."

Nonsense, say those who favor turning Klingle into a path. They contend that the most vocal eastsiders are themselves well-to-do residents who like the lower housing prices in the east but head west for private schools and shopping.

To fight the image of elitism, the westside group collected more than 5,000 signatures from residents east of the park who support keeping the road closed. "The myth that we are elitists trying to keep this as a private park is BS," said Ralph Scott, who recently moved to Capitol Hill. "It's the most effective lie that the other side can use."

Klingle Road winds uphill from east to west under Connecticut Avenue. Its pavement is cracked and its stone retaining wall eroded.

In 2001, a consulting firm hired by the city produced a $200,000 study that found that reopening Klingle would have a negligible effect toward easing traffic flow.

In written testimony for a public hearing in January, Mayor Williams (D) said that "rebuilding Klingle Road for vehicle traffic is a bad idea. The minimal benefit that would result from such an expensive project cannot be justified."

Some activists say there is evidence that the Woodley Park contingent has the mayor's ear: His spokesman, Tony Bullock, who lives in Woodley Park, wrote a personal letter to The Washington Post in April 2001 that argued for Klingle Road to be closed.

"The Tony Bullocks of the world feel privileged, like they are the elite and want that enclave just for themselves," McKenzie said.

Bullock responded that "since I became the mayor's communications director, I have not been publicly active in that group."

Those pushing to reopen Klingle say they will lobby the next mayor if Williams blocks them.

Hearing that, Jason Broehm, an Adams Morgan resident who supports keeping Klingle closed, said: "It's frustrating that it's taking so much time from so many activists who could be working on other issues in the city that are just as important, if not more so."

Scott Bush, who wants Klingle Road turned into a recreational path, brought his dogs Woodlie and Heloise along to demonstrate Saturday on Connecticut Avenue.Tessa McGee, left, mom Laurie Collins, Jeanne Ingram and Peter McGee on road they want reopened.