W. Edward Bohrer Jr., a lifelong resident of Gaithersburg, easily won the office of mayor of that city yesterday in an election that political observers called a clash between older Gaithersburg and newer forces moving into the rapidly developing area.

Bohrer, 45, a three-term city councilman, got 1,/050 votes to the 445 cast for Vicky York, a 30-year-old real estate sales manager, according to an unofficial tally. When the results were announced at 9:30 last night, Bohrer let out a sigh of relief, smiled and hugged his wife and son.

"This is a vote for Gaithersburg," said Bohrer, who had been handing out campaign literature to voters at City Hall all day. "It has nothing to do with the new or old guard."

City Council members Sidney Katz and Gertrude (Dolly) Kildee overcame a challenge from Augusta (Kay) Bolling to retain their seats. About 1,521 citizens, slightly more than 12 percent of Gaithersburg's registered voters, voted.

Since the two mayoral candidates had not disagreed on political issues in the campaign, the race appeared to center on a difference in style and whether voters wanted a newcomer or an experienced hand to shepherd the booming city into a new era.

The Montgomery County Board of Realtors had thrown its support behind York, accusing Bohrer of viewing Gaithersburg as "the cow town it was 20 or 30 years ago."

One of the area's most active citizens groups, the Westleigh Citizens Association claiming to represent about 500 residents, supported Bohrer because of York's backing by builders and developers. "The city election sends a message to the Montgomery County Council that developers and realtors cannot control the outcome of an election when the citizens are informed," said B.K. Singh, president of the group.

Gaithersburg is at the heart of the the Montgomery County Council's debate over the rapid development that has strained the area's schools and outstripped county and state construction of new roads and road improvements, causing unprecedented traffic jams.

York said after the returns were in that she "ran to give the voters a choice. I wanted the candidates to actually get out and campaign and hear their constitutents. I hope the council will consider me for the council seat that will be vacant as a result of the mayor's race because I care about Gaithersburg." The City Council plans to appoint a replacement for Bohrer.

"I feel tremendous," said Bohrer. "I have no further political ambitions. All I want to be is the mayor of Gaithersburg and a damn good one."