There was something oddly familiar about the grumble that greeted Betsey Williard as she told her mother of her plans to leave Wheaton and move to Gaitherburg,12 miles to the north. "You might just as well be in Texas like your sister," her mother complained.

The remark triggered memories. Thirty-six years ago, when Mrs. Williard's father and mother left Washington's inner city for Chevy Chase and the new world of suburbia, Mrs.Williard recalled, "My grandmother asked them,'Why dp you have to move so far into the country?'"

Back then, as World War II began, Chevy Chase was the last stop on Washington's northwestern bus lines. Far distant Gaithersburg, a country market town on the Cumberland-to-Washington railroad, another world, populated by farm wagons, blacksmiths and mills.

Then th highway came through. Between 1956 and 1963, the four asphalt lanes of Interstate 270 - known then as I-70S - crept southward from Frederick and through Montgomery Country's farmland to the Capital Beltway.

When that happened, one era of growth in Montgomery County ended and another began. No longer would the homes and lawns gently multiply, one layer of development folding smoothly across the last, the way they had done from Chevy Chase to Rockville.

Now the suburbs started to leap northward along their new asphalt lifeline. From the northern edge of Rockville out through Gaithersburg, the landscape changed.

First came the long, low office and light industry buildings of IBM. Comsat, and Fairchild, the federal government's Bureau of Standards and the Atomic Energy Commission. Then the suburban streets started to snake through the fields and the clusters of clapboard and shingled houses sprouted along them like a runaway new crop in what had been fertile farmland.

The 33-mile-long new highway created new communities. Tied to the Washington-area economy, yet surprisingly self-sufficient for suburbia, they have spawned a culture built around the automobile and industries and commerce built around the road. It is a world of crowded schools and crowded swimming pools, high-rise hotels, shopping malls an take-out * Chinese restaurants.

Yet here and there amidst suburban tracts of homes, there still sits an occasional silo, forlon and empty casting a long shadow over somebody's garage.

In this area which local government planners have dubbed the "I-270 Corridor," an area stretching from the northern edge of Rockville out past Clarksburg, 30 miles from downtown Washingston - there were, in 1960, no more than 10,000 people. Now there are nearly 63,000 people and 34,000 jobs. By 1984, nearly 53,000 people are expected to be working somewhere near this long stretch of asphalt.

Gaithersburg where Betsy Williard moved in 1974, wwas the first and most massive creation, the upstart child of the highway and the research and development industry that followed it northward. Where there were 8,000 people in 1960, there are54,000 today.

These new migrants habe brought with them a distillation of the culture of the 1970s, patterned to fit a suburban framework. New apartments fill the hollows of the old farmland. New $110,000 homes sit on the hillsides. Single clubs blossom amid the town houses, many women join the men on the early-morning trek to the office. Here the car is essential, and most families havetwo of them.

Still, "basically they're the same kind of people who lived near my parents when I was growing up." said Betsey Williard. "They're professional people trying to give their kids the best of what they have."

Most of them - nearly 37 per cent, by one estimate - come from states outside the metropolitan area while another 20 per cent are expatriates from the older suburbs in down county Montgomery. With a median age of about 27, they are the youngest group of people in the entire county.

Mrs. Williard and her two children joined this migration in 1974, buying a town house in Montgomery Village for$37,000. She had divorced her husband shortly before and "in Wheaton I felt completley cut off from everything."

It's different, she says in the newtown development of Montgomery Village, which was started 10 years ago on the northern outskirts of the old market town of Gaitherburg, and which houses 17,000 people now. "There's a closeness in the village." she said. "And you're not too far from anything downtown with I-270 nearly."

"The highway took Gaithersburg out of the boonies," explained william Hurley, an executive of Kettler Brothers, the development firm that built Montgomery Village and gave Gaithersburg a brand new image.

"Almost as important to development through." Hurley added, "were the federal installations and the scientific industry that came with it . . . As the scientific industry moved on out the road, it provided a base for housing."

At present, more than half the people who live in the long strip of roadside land that has been designated the I-270 corridor work in or near that same long strip of land. Kettler executives estimate that about 40 per cent of Montgomery Village residents work along the I-270 corridor.

None of those jobs might have been there had their been no Cold War. In the 1950s, when the threat of nuclear strike seemed a part of daily life, government officials decided to move large parts of the government apparatus away from the banks of the Potomac.

T"Government officials wanted major technical and scientific agencies to be at least 20 miles from the White House,"so that a single nuclear strike would not bring the entire government to its knees, explained Fred McGehan, a spokeman for the National Bureau of Standards.

But McGehansaid, agencies like the Bureau of Standards worried that half their staff might desert them if they chose to move too far away from their employees' homes. In fact, a survey showed, many of the employees lived out in far Northwest Washington and in Montgomery county near the beginning of the I-270 corridor.

"We realized we'd have to go northwest," McGehan said. So in 1966, the Bureau of Standards opened its new facility on 580 acres beside I-270 in Gaithersburg. Just over 3,000 employees work there today.

By the time the Bureau of Standards moved, the Atomic Energy Commission has already opened a huge facility 5 miles to the north, near the tiny hamlet of Germantown. Then the research firms started to grow like weeds along the corridor: IBM came, then international construction conglomerate Bechtel, then Comsat.

"When you have the corridor as the location of government itself, the research and development types come in. They all have a tendency to feed each other," said Bill McCullen, an IBM executive who helps run an organization called the I-270 Employers' Group.

"Then," he added, "a high percentage of the people in Montgomery County's work force are professionals and managers. That might have been a catalyst."

That reasoning is familiar to Marie Garber, who has kept a sharp eye on the changes in the county for the last two decades from her vantage point at the Board of Elections office.

"It all goes back to E. Brooke Lee," she said, referring to the powerful, wealthy man who was Montgomery County's political boss throughout the fomative years of the downcounty's growth in the 1930s and '40s. For Lee knew what kind of county he wanted, and he knew how to manipulate the political process to get what he wanted.

Lee, the scion of one of Maryland's oldest families and the father of the present Acting Gov. Blair Lee III, planned the future of his county carefully. Rich, well educated people followed the trail of expensive homes and large lawns that Lee left behind him. There weren't, until recently, many places for poor people to go in the county.

"Research and development came because that was the character of this community." said Marie Garber. "Brooke Lee had this place ready to come to."

Interstate-270 just gave them one more raod by which to come. Even the route of the highway was not new - in designing their new interstate. Maryland highway planners followed a route established in 1774.

Eventually, Maryland Ric. 335 - changing its name like a chameleon from Wisconsin Avenue to Rockville Pike and then to Frederick Avenue as it headed north - moved up through the county, in and out of Rockville and Gaithersburg and out to Frederick.

When it came time to design Interstate 270, "We just built (parallel to) that (existing) north-south alignment." said Bob Martin of Maryland's Department of Transportation.

Everything the new highway touched, it changed. From a population of about 25,000 in 1960, three years before the road was finished, Rockville has grown to 50,000 people today. But the population of the Gaithersburg area long a would be rival to Rockville as the premier city of the nation's second-wealthiest county, has now supassed that of the county seat.

That is the kind development the planners wanted. For with the coming of the road, the Maryland - National Capital Park and Planning Commission decided that an invaluable asset had been laid down in their midst, a tool that could be used to stop the juggernaut of sprawl.

So evolved a plan the M-NCPPC grandly christened "The Year 2000 plan," where they first enunciated the theory of wedges and corridors. In general, the plan decreed that new minicities should be strung like beads along the highway, leaving the wedges of landscape around them green and almost untouched.

"Following (the development of that plan) the park and planning commission started discussing their plans with us, as an owner in the area," said Kettler executive Hurley. "We started to acquire more land in 1963 and '64." Two years later came the town sector zoning they needed to put their development together.

At the same time, other developers were making plans to turn the fields into such developments as Quince Orchard. Orchard Pond, and Diamond Farms, to the west across I-270 from Montgomery Village.And the town fathers of Gaithersburg, anxious to have their own controls on growth, started annexing vast tracts of nearby land.

It all happened so fast that some oldtime residents swore you would miss the new construction if you blinked. Allen Katz, eldest son of a local department store owner, left his hometown for the Army in 1968.

When he came back 1971, most of the streets were new to him. "When I first came back," he said, "I met a girl in Washington, and she said she lived on Lost Knife Circle in Gaithersburg. I thought she was kidding. I didn't know there was any such place."

There hadn't been when Katz left for the Army. There hadn't been many traffic jams either, outside of the small main street of town. But there were now. Everywhere. At the morning and evening rush hours, the intersection of Montgomery Village Avenue and Rte. 355 looks like New York Fifth Avenue at midday.

Just where all those people came from was the subject of a survey taken in Montgomery Village by the Kettler Brothers manager. They found that some 20 per cent of Village residents had come from down county: Silver Spring, Wheaton, Bethesda and Chevy Chase. Another 10 per cent had come from Rockville.

But a greater number - some 37 per cent - came to the new part of Gaithersbury from states outside the Washington metropolitan area. Their roots, if they have any in an age of transience, are elsewhere.

Still, according to Ed Crowley, Kettler Brothers vice president for business affairs, the lack of history has had "no effect at all . . . I don't think many kids around here fish in the ponds where their dads fished 25 years ago, and I don't think their dads give a damn."

Instead, those that move there seem to do so because they enjoy the mixture of gregariousness and privacy that they find amid the communal green space and the carefully selected shrubs.

"I made more friends my first six months in the Village than I did in a whole 2 1/2 years in Silver Spring," gushed Nereid Maxey, who moved into the Village in 1973 with her 13-year-old daughter Dore.

"It's God's place," she added. "I've never seen an area more beautiful or more planned."

That planning includes a long set of cevenants that govern things like the color a resident can paint his or her doors and whether a retractable clothesline can be hung outside a house.

Residents pay $60 in annual dues to the Montgomery Village Foundation, an organization that oversees supervision of such amenities as the eight swimming pools and 23 tennis courts, and the ball fields. These are the places where the children gather, but, with the exception of the tennis courts, not many of their hard-working parents come with them.

The Village has many of the same problems that nag other suburban communities: it's difficult to find adults eager to coach young sports teams or to serve as scout leaders, and homeowners complain about the neighbor's dog in their gardens.

But those things don't decrease the popularity of the Village, which is almost halfway to its eventual goal of a population of 35,000. Homes values, like those in the rest of the Washington area, are skyrocketing: the fashionable Whetstone section, where the top price in 1971 was perhaps $65,000, now has somes selling as high at $110,000. And there's room for still more growth.

Half of the land within Gaithersburg's city boundaries - land that was mostly annexed to the city after 1960 - is still vacant, according to city planner John Maynard.

"The railroad made this town to begin with," he said. "The highway has made it over."

Next: Change in Germantown.