Margaret Schmid's one-story house is enveloped in woods and shielded from the lights of metropolitan Washington. Being removed from urban development is one reason Schmid, a child health policy advocate, moved to Accokeek five years ago.

But that, she fears, might change. In 18 months, Wal-Mart plans to open a 135,000-square-foot store and a parking lot for 800 cars three miles from her house.

The developer, TSC-Muma Mattawoman Partnership, has yet to submit site plans to the county for the 422-acre residential and commercial development that is to include a Wal-Mart. But the mere announcement of the retail giant's plans has sparked a tug of war between community activists and the developer over the use of the 39-acre plot near the intersection of Routes 228 and 210.

Accokeek, an unincorporated area of Prince George's near the Charles County line, has a history of environmental activism and a small-town culture that some of its residents say a Wal-Mart would destroy.

"A Wal-Mart is such an invasive use; it is totally, inordinately large," said Schmid, founder of the 130-member Citizens for a Liveable 210, a group of Wal-Mart opponents. "This is an area where you need smart growth" because the area already deals with heavy traffic and crowded schools, she said.

But Wal-Mart, the largest retailer in the world, said it is abiding by zoning rules and following the market. "The 210 corridor is a very attractive development area, with residential growth as well," said Keith Morris, director of community development for Bentonville, Ark.-based Wal-Mart Stores Inc.

Accokeek grew from 1,737 residential units in 1990 to 2,642 last year. "Number-wise, that is not huge, but relative to Accokeek, that is huge [growth]," said Craig Rovelstad, a planner at the Maryland-National Capital Park and Planning Commission.

In fact, the whole area is a golden target for Wal-Mart, which also is planning to build a 129,000-square-foot store in Clinton, 18 miles away. It also is considering a store in La Plata to add to its existing stores in Bowie and Waldorf, the latter just eight miles from Accokeek.

The Accokeek Wal-Mart would be on residential- and commercial-zoned land, 26 acres of which will be for the Wal-Mart, on the south side of Route 228. The residential portion, consisting of 106 single-family homes and several hundred senior living units, will be built on the 383 acres that are now woods and fields. Details for the commercial portion, including architectural and design changes, are still being hashed out and will be submitted some time in the fall, said Dario Agnolutto, the developer's attorney.

The battle before the county planning board will be over whether the developer's plans for Wal-Mart meet various zoning criteria. At issue will be the store's "compatibility" with existing and proposed development.

Rovelstad said those requirements are subjective and "that subjectivity is going to be the thing that makes or breaks" whether Wal-Mart comes to Accokeek.

Battles over Wal-Mart's entry into small towns have flared across the country. Albert Norman, of Greenfield, Mass., worked to block a Wal-Mart in his home town six years ago and has since published a book on how to stop Wal-Mart and created a Web site (www.sprawl-busters.com) that have made him a leader in the national grass-roots movement against megastores. The Accokeek group has been in touch with him.

Norman said he knows of more than 60 communities that have forced Wal-Mart to withdraw because of pressure from citizens groups, city council votes or a ballot initiative. But Wal-Mart's Morris said, "It's a land-use decision, not a land-user decision, and it shouldn't be a popularity contest of what we want in a town."

Agnolutto said the developer and Wal-Mart have been willing to accommodate residents' wishes through architectural and design changes but won't accept a no-Wal-Mart policy. "Give us a list of concerns, and we will address them," he said, "but if it's a matter of, 'I don't want a Wal-Mart,' I can't do anything about that."

That hasn't stopped Schmid and others from lobbying the county and the media, and conducting studies of how traffic and businesses along the Route 210 corridor might be affected.

Tammy Douglas also is wary of Wal-Mart. She and her husband moved into their $400,000 home in Accokeek a 1 1/2 years ago with no expectation that Wal-Mart would be their neighbor. "I didn't move to Accokeek to shop; I moved to Accokeek to enjoy life," she said. Besides, she said, there's already plenty of vacant retail space along Indian Head Highway.

County Council Chairman M.H. Jim Estepp (D-Upper Marlboro), who represents Accokeek, also objects to the Wal-Mart because, he said, "it is inconsistent with the development in that area." Though Wal-Mart's proposal is consistent with the zoning laws in Accokeek, he said, "I would hope that they will listen to the communities."

Agnolutto said he expects to garner community support for Wal-Mart. "If I have all opposition and no support, I'll lose the political battle," he said. "The community groups by and large carry the political day," he said.

CAPTION: Phil Jones, left, Margaret Schmid and Emily Canavan divide a stack of anti-Wal-Mart fliers that they plan to distribute later.

CAPTION: Margaret Schmid, left, Emily Canavan and Phil Jones are members of a citizens group that opposes a planned Wal-Mart store in Accokeek.