One steamy Saturday last August, not long after her 18th birthday, Betty Jo Taylor left the peach trees and rooster calls of her family home in nearby Musick Hollow and rode a Trailways bus 13 hours into Washington.

Her destination was a pastel green console full of fingerprint file cards, one among endless ranks of them, on the air-conditioned 11th floor of the FBI headquarters building.

Taylor is one of tens of thousands of clerical workers hired by federal agencies in Washington every year, most of them young women. FBI headquarters here alone employs about 7,500 people, of whom only 600 are special agents. The rest - 92 percent - are clerical "support" staff, officials said.

The bureau must replace about 2,000 clerical workers each year at headquarters, they said, compared to only about 800 at the Central Intelligence Agency.

There are never enough recruits for this typewriter army, officials said, especially not enough who meet the personal and professional requirements of such a security-conscious agency.

Like the agents, the clerical recruits must pass background investigations. "Our approach is different from [regular civil service recruitting], probably a little more difficult," said FBI recruitment specialist Ralph E. Lawrence.

Usually fresh out of high school, many of the recruits come from places such as Harrisburg and Johnstown, Pa., from Salto Rock and Big Ugly and Peach Creek, W.Va., where people go to church three times a week and are active in the PTA and Little League baseball.

"I think most of them still do adhere to the old traditional values," said Mary Watson, the FBI "den mother" to new recruits, who herself moved here 28 years ago from a Tennessee farm. "In a small town, there's not so much to do, so they come out for parades."

Those from larger cities tend to "expect more and want more", she added.

Some think that, because their employer is the FBI, their work will be "in the middle of the action, working on bank robbery cases," and instead they find themselves filing or pushing a message cart, she said. "This can make them frustrated. We try to impress on them the need to start with routine work. They can't start at the top."

Yet the same traditional American virtues that send the FBI recruiters into the backwaters and small towns looking for these young people makes them vulnerable to big city blues and homesickness and an early return bus ticket.

Betty Jo works the night shift, from 4:30 p.m. to 1 a.m., searching for arrest records, and seldom strays from the bus route between her job and the two-bedroom apartment in Alexandria's "condo canyon" which she shares with two other young women.

One of nine children, she is "the independent one," as her sister Norma put it, brave enough to leave this job- poor coal mining community tucked among West Virginia's green mountain ridges, on the two-lane road between Varney and Pie.

Despite fears about city crime and other perils, her father, Jim Taylor said it makes him proud. A soft-spoken giant of a man, Taylor has worked hard at various factory and strip mine jobs and is currently employed as a custodian at a nearby high school.

"It helps the place, here, and it helps her. And I don't know of a better employer she could have, do you?"

The Taylor home is the last one up the hollow except for Betty Jo's grandmother's house. It has no phone and is linked to the nearest paved road by about a mile of rutted mud trail. Beside it, Pigeon Creek runs clearly between occasional rusting auto bodies and pungent hog pens.

Jim Taylor believes West Virginia is - like the license plates say - "Almost heaven." He likes to show off his peach and cherry trees, and his children, and desires, he said, to travel no farther than the nearby Guyandot River, where he is content to swim and fish with his family.

His daughter, meanwhile, a fair haired self-possessed young woman who loves to read books, has survived several traumas. She got on the wrong bus in suburban Northern Virginia, during a thunderstorm, she said. And she has almost gotten used to sharing a small crowded swimming pool ringed by parked cars, instead of having a river virtually to herself.

Betty Jo Taylor feels tugged from two directions, she confesses. She wants to take some courses here, move up in her job, do something interesting. But at the same time, she misses home.

"Peoples' jobs are so important here," she said, "back home, you know, they're just one part of everything . . .

"There are so many people here," she adds. "It doesn't seem very important that I'm here."

Homesickness and other pitfalls, costly in terms of turnover, rank high on the FBI enemies list.

The agency recently introduced a new regional recruiting program that focuses on the states closet to Washington, rather than nationwide, and encourages multiple recruits from the same area, to lend each other moral support.

Some employes avoid homesickness, as well as the high cost of city living, by long-distance commuting. They wake up at 4 a.m. in places like Charles Town and Martinsburg, W.Va., and Baltimore, and spend several hours each day on trains and specially chartered commuter buses.

"Seems like my whole town commutes in," said Mikell Stephenson, 20, who rides in from Charles Town every morning.

And when Deborah Wilson, 22, of Bunker Hill, W. Va., applied for a job three years ago, her mother Dorothy 46, went along and got hired at the same time. Now the whole family commutes to Washington, the father working as a plumber at the Pentagon.

Those who make the move to Washington get a special agency orientation program, recommending certain apartment buildings and setting out for them a code of acceptable behavior, such as "be punctual," "stay away from dope," do not live with a member of the opposite sex and do not give away company secrets.

FBI recruiters make the terms clear from the start.

"If you've been drinking holy water (liquor) or smoking pot out under the stands at ball games, or fighting, or if you've broken into a store - now, we don't need that type of an individual in the FBI, special agent Gifford Basham, 42, sternly told a room full of seniors last week at Guyan Valley High, near here.

The school's walls were missing chunks of plaster and the old wood floors smelled of oil polish. Basham passed around a color photograph of the J. Edgar Hoover Building on Pennsylvania Avenue.

A pretty gum-chewing flirt on the first row asked him, "can we wear blue jeans to work?"

"Nope, we draw the line at that," Basham said.

He has put 10,000 miles on his four-wheel-drive Ford Carryall just since January, he said, winding over mountain roads and flood-prone bottom land to 130 high schools in six counties of West Virginia.

Last year about this time, it was Basham who recruited Betty Jo.

Boyishly handsome in the G-Manmold, Basham is himself part of the cycle. The son of a West Virginian coal miner, he was a star high school athlete who married the homecoming queen. He was recruited into the FBI in 1966. Many of the teachers and counselors he deals with are former classmates.

Comfortable in the school rooms, or on family porches, like the old Bible and kitchen-supply salesman, Basham combines a line of patter about the FBI's benefits plan with knowledgeable analyses of the local basketball team. He might pick up a little information about some fugitive hiding out in the neighborhood at the same time he rounds out a background check a young job applicant.

He dropped in that way on Betty Jo's father and mother last week, patting the smaller children on the heads, chatting about gardening techniques and trading news.

Mark, the youngest Taylor boy, "can already read better than I can," Taylor said. His wife Mary tried to persuade Basham to stay for a fish supper.

But not all Basham's connections are so rewarding. At one school, where last year's seniors were friendly and receptive, this year they "had no interest in anything but hot cars, drinking beer and smoking pot," he said. "And they had lower test scores."

In some areas, the very idea of Washington seems to put off potential recruits. The Guyan Valley school, located in one of the poorest counties in West Virginia, is one of these.

"The boys would rather work in a service station making peanuts than do clerical work," said counselor Pam Curry, once a student there. "Most of them work up the hard way, at factories or steel mills; a lot of them go to Detroit or Cleveland."

Of the people in the county who work, 92 percent work outside the county. And 75 percent of the student body come from families on welfare, she said.

As for the girls, "There is a concern here about blacks in the city, and crime. No blacks even live in this county, and there is a strong fear of the unknown."

Recruits from the city, or the country, black or white, often find the high costs and other drawbacks of downtown Washington jobs forbidding, officials said.

"If the headquarters was outside the Beltway, like NASA, or Social Security, the turnover would probably be drastically less," said Frank Rabena, of the FBI's most prolific recruiting office, based in Baltimore. Most of his recruits, he said, are black.

The new recruits come in scared. "They don't know how to take us, and if they're from the country, they just don't know about certain things," said FBI den mother Watson, whose office fields recruits' calls about money problems, troubled romances, and other crises.

"One time when we said we had an apartment with utilities included, we had one who wrote back and said, 'I'll bring my own utilities.'"

One young recruit, impressed with the FBI's warning that there should be "no publicity" about his new job, she said, went so far as to pack his bag in the middle of the night and climb out a window of his parent's rural home to embark on his government career.

Working for the FBI as a clerk might be just as boring as working for anybody else as a clerk, but "all that security, the guards and checks and everything, make you fell like you're important," said one fledgling G-woman, who said she was a fan of TV's Efrem Zimbalist Jr. of the "FBI" show.

"Working here makes a difference to other people, like your parents, who don't know what the job is actually like," said another. "It impresses them."

"I wanted adventure, I wanted to get away," said Betty Jo Taylor's roommate, Dorothy Flynn, 19, of Johnstown, Pa. She works the night shift with Betty Jo, and also works 15 or 20 hours a week at the Yogurt Hut because she said, "I like to keep busy."

She and Betty Jo, relaxing in their borrowed and second hand furniture in their Alexandria garden apartment, decided that they feel pretty comfortable with their pay and prospects, for now, and after all, the homesickness may pass.

"They do help you out a lot here," Betty Jo said. "It's a pretty good start, and you have to start somewhere." CAPTION: Picture, FBI clerk Betty Jo Taylor in her apartment. By Linda Wheeler - The Washington Post; Picture 2, Dorothy Flynn visits roommate Betty Jo Taylor on the job at FBI headquarters. Flynn is on the break from her job. By Linda Wheeler - The Washington Post