People who live behind the fast-food joints, car repair shops and strip malls lining a nondescript stretch of Route 1 in southeastern Prince William County can be forgiven for not knowing where they are.

They think they live in Woodbridge. And until last week, they did.

But now they live in a place called Marumsco.

Marumsco is one of Prince William's seven new "census-designated places." It effectively consumed most of Woodbridge, gobbling up about 80 percent of the land mass and almost 90 percent of the residents.

But nobody bothered to tell the Marumscans. And many of them say they want no association with the name, even if they live in subdivisions called Marumsco Acres and Marumsco Woods, send their children to Marumsco Hills Elementary School or visit the barber at the Marumsco Shopping Plaza.

The demographics of Marumsco and the new, smaller Woodbridge are strikingly different, a gap that some residents said gives Woodbridge more panache.

"I'm glad I'm moving if I can't say I live in Woodbridge anymore," said John Armstrong, 62, a government contractor whose house has been foreclosed on. "To me, Woodbridge suggests upscale and successful. Marumsco is just a shopping center."

After every 10-year U.S. Census, many places are given new names in the sprawling, unincorporated suburbs of Maryland and Virginia. The census bases its maps on the advice it gets from local officials.

In Prince William, places such as Marumsco, Bull Run Mountain Estates and Neabsco - all new designated places - exist solely on census maps, and the designation has no effect on how the areas are governed or policed, or how the mail is delivered.

But because place names can reflect and amplify the identity of those who live there, new names can be contentious.

John Kent Cooke aroused indignation when he named the Landover property around Redskins Stadium "Raljon" in tribute to his sons Ralph and John. But he stuck to it, until new team owner Dan Snyder reclaimed the old name.

Marketers for National Harbor initially considered a separate Zip code for their massive, upscale development so they wouldn't have to share one with the less- flashy Oxon Hill.

The mountain that Alaskans call Denali is still called Mount McKinley by the U.S. Board on Geographic Names.

"Names are very important to people," said Richard L. Forstall, a former census official who served on the federal board when the Denali vs. McKinley naming debate erupted 30 years ago. "They have associations, mainly for local people."

The name Marumsco, an Algonquin Indian name meaning island rock, was adopted for subdivisions of small tract houses with two or three bedrooms, one bathroom and no garage that predominate in the neighborhoods off Route 1. In recent years, many of the homes with choice views of the Potomac River have been torn down and replaced by showplace mansions with three-car garages that at the peak of the housing boom sold for more than $1 million.

Today, those neighborhoods are filled with "for sale" signs, and many of the grander homes have been emptied of furniture.

Severing Marumsco from Woodbridge has created two places that look different on paper. If Marumsco were still a part of Woodbridge, it would have 39,000 residents, 39 percent of whom would be Hispanic, 30 percent white and 21 percent black.

The new Woodbridge has about 4,000 residents, 51 percent of whom are white; Hispanics and blacks each make up about 18 percent of the population. Woodbridge has a marina, townhouses, golf courses and plans for luxury condominiums to be built once the economy picks up.

Marumsco has 35,000 people - 41 percent Hispanic, 27 percent white and 21 percent black. It has a new Todos supermarket due to open this month on the site of a former Giant grocery in the Marumsco Shopping Plaza.

Bill Vaughan, Prince William's demographer, said Marumsco had experienced so much development over the past decade that studying it independently of Woodbridge was a way to collect more data about its residents. He said there was no discussion among Prince William officials about the demographics of the new community compared with the old one. County Supervisor Frank J. Principi (D-Woodbridge) said he raised no objections when county officials reviewed Marumsco.

Census guidelines say place names should be ones commonly used in conversation. After a new name is bestowed, local officials are advised to publicize it, census officials said. Vaughan said no one suggested that to his office.

Most people interviewed were surprised to learn they live in Marumsco.

"The area is known as being Woodbridge," said Carlos Castro, owner of Todos supermarkets. "To change it to Marumsco for some reason doesn't sound so attractive to me. It just doesn't sound so hot."

Jackie Gabelia, 89, who moved into the area 45 years ago and raised a daughter in the two-story home she and her husband bought brand new, said many of her friends couldn't find Marumsco Shopping Plaza, much less the community.

"I always thought I lived in Woodbridge," she said. "I just can't understand why they changed it."

People disagreed over whether it matters.

"The people who live here are going to say they live in Woodbridge," Principi said as he drove past homes in Marumsco Acres. "And no census bureaucrat is going to change that."

But Connie Moser, president of the nearby Dale City Civic Association, said prospective homebuyers who visit online real estate sites may be advised by other readers to look in Woodbridge instead of Marumsco.

The controversy illustrates how difficult it can be to pin down a sense of place in the Virginia suburbs.

"We don't live in a town or a city," said Moser, who recalled that county officials advised her to look at a census map when she was trying to figure out Dale City boundaries for a membership list. "It all falls under the county. No wonder we have an identity crisis."

Moser said she sometimes gives Dale City as an address for her mail but sometimes writes Woodbridge. The mail gets where it's going just the same.

That's because the entire area uses the Woodbridge post office - which is in Neabsco.

Staff researchers Dan Keating and Magda Jean-Louis contributed to this report.