Vickie York is an energetic 30-year-old real estate sales manager who moved into a new Gaithersburg town house two years ago. She was one of the thousands of young professionals who, attracted by the giant companies that now line nearby I-270, have made the upper Montgomery County city one of the fastest-growing communities on the East Coast.

W. Edward Bohrer Jr., 45, is an insurance salesman who was born in Gaithersburg, went to the local high school and lived there all his life, most recently in a two-story single family house in a 15-year-old neighborhood.

They are both running for mayor in a battle that some say is pitting Gaithersburg's old guard against the new forces moving into the booming city -- an area at the heart of the growth debate rocking the Montgomery County Council.

No city more than Gaithersburg represents the forces of rapid development fueling the construction of thousands of new town houses and office buildings in the county during the past few years. Development there has strained the area's schools and outstripped county and state construction of new roads and road improvements, causing unprecedented traffic jams.

Despite the hotly charged debate over growth in the county, Gaithersburg's mayoral candidates don't disagree about what their solution would be. Both have made the same promise to pressure county and state officials to pour more money into new roads to relieve traffic congestion.

Instead the race has become one of style -- a classic clash between one candidate who remembers a simpler, slower Gaithersburg and another who only knows the city as the boom town it has become, some political observers say.

The choice is between "a difference in style and whether voters want a new face coming in," said Mayor Bruce A. Goldensohn, who is stepping down to run for the Montgomery County Board of Education.

One prominent Gaithersburg businessman worries that the political ambitions of the newcomer to Gaithersburg may supersede the area's interests.

"We don't want someone who is just passing through in pursuit of a higher political agenda," said Jon A. Gerson, executive director of the Gaithersburg and Upper Montgomery Chamber of Commerce.

"I think Bohrer is favored in the race," added Gerson, stressing that the chamber cannot endorse a candidate. "He's a fourth generation resident of Gaithersburg who has enjoyed a strong rapport with the business community."

Yet Harold Huggins, legislative chairman of the 6,000-member Montgomery County Board of Realtors who supports York, has a different view. "Bohrer views Gaithersburg as the cow town that it was 20 or 30 years ago," he said. "It's more than just a cow town or a suburb of D.C. now . . . . And we think York is the person to give Gaithersburg the new vision and new direction that is so needed to guide the city."

"That's absolutely preposterous," responded Bohrer, who said he has "participated as a city councilman since 1974 in seeing that a very small, sleepy suburb of Washington has developed into an extremely exciting suburban city that is a good place to work as well as live."

Gaithersburg's population has soared to 30,000 from about 3,000 in 1960, Goldensohn said.

The number of new houses in Gaithersburg and the surrounding area has climbed from 18,000 to 27,300 in the past decade, according to the Montgomery County Planning Board. The number of workers in the area, attracted by the I-270 high-tech corridor with companies such as International Business Machines, Hewlett-Packard Co. and Bechtel Power Corp., has skyrocketed from 29,700 to 53,000, the board said.

Gaithersburg's mayor represents the city, which has a separate government from the county, and presides over the council meetings, but the mayor does not have a vote on the five-member council. The new mayor will be paid $5,000 a year.

York, who drives a black Nissan 300 ZX, is described by her supporters as representing "the new energy of Gaithersburg."

York, who works as a sales manager for Dreyfuss Brothers Residential Sales, has lived in the area since 1975. The City Council appointed her to the Gaithersburg Landlord-Tenant Affairs Committee, and County Executive Charles W. Gilchrist appointed her to the Up-County Citizens Advisory Board.

"I think Gaithersburg should have a more aggressive mayor," said York, who hopes to be supported by newer residents, "looking for somebody that is not part of the older establishment of Gaithersburg."

Bohrer, a district manager for Peoples Security Insurance, grabs that argument and quickly flips it on its side. The bespectacled veteran Gaithersburg council member says the city needs a sound, politically experienced leader to shepherd it into a new era.

"The voter will have the choice of experience as opposed to deciding to take a chance on someone who is much less known," said Bohrer, who served on the Gaithersburg Planning Commission for four years before joining the City Council 10 years ago. He argues that York's proposals are programs he has always supported. If he loses his bid for mayor, Bohrer returns to the council, where his term does not expire until 1988.