On opening day 25 years ago, lines of cars stretched for more than a mile along the roads of the Wheaton commercial district. Twenty county police officers worked to control the traffic jams as more than 50,000 people came for their first look at Wheaton Plaza, the Washington area's largest shopping center.

Although since surpassed in size by other malls, Wheaton Plaza has remained one of the Washington area's most financially healthy shopping centers, according to the federal Census. About a third of the original stores are still there.

Business has been good from the very first day, said attorney H. Max Ammerman, who owns the plaza along with developers Homer Gudelsky, Simon Sherman and Theodore N. Lerner.

In a U.S. Census Bureau listing released this year identifying the Washington area's top 10 retail centers by annual sales, the 202 stores of Wheaton Plaza and its surrounding neighborhood placed fourth, with $226 million in sales in 1982.

Topping the list was the downtown Washington shopping area of F Street with 804 stores and $556 million in sales that year, White Flint and lower Rockville Pike with 158 stores and $296 million in sales and Congressional Plaza and upper Rockville Pike with 152 stores and $275 million in sales. Tysons Corner, with 125 stores and $225.5 million in sales, placed fifth.

In the Census' 1977 listing, the Wheaton Plaza area took third place with $209 million in sales.

All of the plaza's owners, except Sherman, also built Tysons Corner, which they have since sold. Lerner and other partners built White Flint and Landover Mall. Gudelsky, along with the estates of his two deceased brothers, holds the major interest in Wheaton Plaza.

Ammerman said the Wheaton location of Montgomery County's first regional shopping center was chosen because a large tract was available there and because there were major roads and burgeoning housing development in the area.

Downtown Bethesda, Rockville and Silver Spring already had shopping districts, although only smaller versions of the downtown Washington style of shopping. Wheaton in the 1950s had scattered groupings of small service shops.

County planners say the plaza has profited from the stability of the area, which was built up after World War II as returning GIs obtained VA financing for houses.

Located on an 81-acre tract that once was the site of a farmer's market, the shopping mall still is a long, rather plain structure surrounded by vast parking lots with 1950s-style pedestal bus shelters and two office buildings.

Long accustomed to being a central meeting place for teen-agers in the Wheaton area, it increasingly draws the elderly, who shop and socialize there -- and exercise.

In recent years an erector-set scaffolding has been added over the two middle entrances of the plaza, part of a roof that enclosed the open air, one-story structure three years ago. Inside, the stores and the style of the pioneering shopping center have evolved with the needs and tastes of suburban shoppers.

While a third of the plaza's original 72 stores are still in business, the newer and smaller stores are a testament to fads and changing life styles.

Gone are the Paris hat shop, children's clothing shops and a Singer sewing machine store and added are a video shop, health food and cookie kiosks and computerized information booths.

Where the Charcoal Hearth restaurant and a one-screen movie theater once operated are a fast-food Burger King and a triple-screen theater. An additional seven-screen theater is scheduled to open soon.

When the plaza was enclosed in 1982, it also underwent extensive renovations that brought it into line with more modern shopping centers, its managers said.

The round central fountain was removed because "it would make too much noise indoors," said Anne Korff, marketing director for the plaza. Added were oak seating arrangements, plants and trees and a brick floor. Many of the shops changed their storefronts and signs.

The new look seemed to revitalize the plaza, whose image was becoming more modest as larger and more modern competition opened around the region, store owners said.

Compared with Montgomery Mall and White Flint in Bethesda and Lakeforest in Gaithersburg, "We looked pretty grubby there for a while," said one longtime store manager. The stores each realized at least a 30 percent increase in sales the first year after the renovations, said Plaza manager Jinny Eury.

The renovations "made all the difference," said Esther Gordon, a Silver Spring resident and longtime shopper who had stopped coming regularly.

Further rejuvenation is expected in the late 1980s, when a Metro station is scheduled to open nearby on Georgia Avenue.

From the beginning, Wheaton Plaza was a shopping center that reacheo of suburban neighborhoods, and Wheaton Plaza is no exception.

Internal Revenue Service audits, musical shows, household loans, morning exercise clubs and demonstrations on first aid are now part of the fabric of the mall. For some, it's a place to meet friends and neighbors.

Three to four times a week, Mildred Jacobs and Sally Stein, two Silver Spring neighbors who are both retired and widowed, come by bus to Wheaton Plaza to have lunch at The Hot Shoppes or the Peoples or Kresge's lunch counters. Afterward they sit on the oak benches to talk and watch passers-by. And they shop.

The plaza is "close to home, a place to go, it gives us something to do," Jacobs said.

"What makes Wheaton Plaza so viable, even though there are more spectacular centers, is its sense of community," said Jane Cartney, who since 1960 has managed the Beckers leather goods and gift store at the plaza. Her very first customers are still coming, she said, and so are their children.