In the two months of filming "Coal Miner's Daughter," the biograhpy of country music star Loretta Lynn, Tommy Lee Jones has established a reputation among the cast and crew as a hell-for-leather driver.

So although Jones, who plays Loretta's husband Mooney, has already rehearsed whipping the jeep around this hairpin curve, the crew is wary. They watch, without seeming to, as Sissy Spacek climbs into the jeep. Spacek, who had a taste of Jones' driving in December, looks frankly apprehensive.

Jones drives straight at the camera, swerves and, overshooting the second turn, plows the jeep into a vine-covered boulder. Spacek marches white-faced to her mobile home. The crew exhales.

The real Mooney Lynn, whose jeep it is and whose dirt road it's on, grins wider than ever. He inspects the battered fender, supervises its uncrimping and then asks casually, "You want me to get the Cat and widen that road a little?"

Nothing fazes Mooney Lynn; not the rise to superstardom of his child bride Loretta, nor their 5,000-acre ranch where this crew of 70 is recreating his life - his and Loretta's. The ironies of the Hollywood presence at his home only mirror the ironies of the Lynns' own vast success in selling her hill-country simplicity. When the movie crew decided to rebuild exactly that little shack he and Loretta lived in back in Butcher Holler, Ky., 30 years ago, it was no more remarkable than the fact that nowdays they live in this vast, Tara-fronted ranchhouse.

And anyway, he's going to move the recreated shack down to Hurricane Mills, alongside the Loretta Lynn musuem, and turn it into a tourist attraction.

"Coal Miner's Daughter" is not some Burt Reynolds Redreck adventure, or a potboiler with fat, evil sheriffs and beautiful girls. It's a $5-million feature with big-time actors and a British director Michael Apted, hot from a hit with "Agatha" "Coal Miner's Daughter" is aimed at a big-city market, not the rural chain-theater circuit.

"I'd love to get Burt's audience in," Apted admits cheerfully, "but they'll walk right out."

Arkansas-born Levon Helm, drummer for the defunct Band, portrays Loretta's father; Beverly D'Angelo, last of "Hair," plays the late country star Patsy Cline. There's a little something for every audience in this film: a love story, a rags-to-riches success story, music, PG language, scenery, and the legend of Loretta herself.As a member of the crew put it, "It's the first movie any of us could think of about a living entertainment figure."

Loretta Lynn is the quintessential Middle American heroine. Born backhill poor in 1936, the second of eight children, she was married at 13 and had four children by the time she was 13. She was four months' pregnant before the doctor explained the facts of life.

She was a front porch and back yard singer all her life, and in 1960, at her husband's instigation, she began picking her little Sears guitar and singing in the local honky-tonks.

That same October, she made her first appearance on the Grand Ole Opry, and in 1963, her first album went to No. 1 on the Billboard chart. In 1972 she became the first woman to be named the Country Music Association's Entertainer of the year, and by 1975 she had worked herself into a nervous collapse. The film, scripted mainly from her best-selling '75 autobiography, runs from her early life in Kentucky through her initial success, to her illness and recovery and return to work.

"Loretta didn't want no candy-coated movie," assert Spacek like a native. Scriptwriter Tom Rickman, also from Kentucky, was responsible for the cream of the earlier country film crop, "W.W. and the Dixie Dancekings." And director Apted, admittedly a novice about country music, has at least escaped growing up with the cliches about "hillbilly music" that haunt most Americans.

There was a point when the film's producers were considering a more lookalike actress for the lead: Cristina Raines. But Lynn said different. "They brought her a stack of 8-by-10s of all the actresses in Hollywood, and she just picked me out," says Spacek, still amazed. "She just said, 'Here's the Coal Miner's Daughter. She never heard of me or nothin'." Spacek believes Lynn is psychic: "She beamed us all here."

In fact, there is some resemblance. Spacek's hair, normally the pale red [WORD ILLEGIBLE] shimmered through her apocalyptic scene in "Carrie," has been darkened to a medium auburn, actually closer to Lynn's true color than the almost-black it is dyed. Spacek's upturned nose can't match the straight profile that is Lynn's Cherokee quarter, but the mouth and eyes are startling.

Unlike Ronee Blakely, who steered her Lynn like character in "Nashville" away from an initation, Spacek has been limitating Lynn for months. She taped the singer's voice and tirelessly "'practiced the rhythm and wide, flat vowels.

"Everybody says Loretta's got a Kentucky accent. Well, she don't. I been in Kentucky, and it's nothin' like it. She's got a Loretta accent," says Spacek. She has it down pat, even the timbre, and "talks Loretta" continuously.

Spacek had to master a dozen songs for the movie, including the title number. "I've finished now," she says with satisfaction. "I've sung 'Coal Miner's Daughter'." The concerts were filmed in front of live audiences at the old Opry House - Nashville's Ryman Auditorium - and the 10,000-seat Municipal Auditorium there. Lynn often appeared with her, to draw bigger crowds; they even sang on the real Opry together. Lynn's band, the Coal Miners, backs Spacek in the film.

"I tell her, when this is over, I'm gonna get a bus and go on tour," Spacek gurgles. "And she says, 'Yeah, and I'm gotta cut your throat!'"

Spacek's good-ole-Texas-girl enthusiasm echoes Lynn's mountain forthrightness. "Her sense of humor is so . . . punchy," says Spacek. "I've gotten pretty funny, let me tell you."

This is the second time in a row Spacek has portrayed a real person (she plays Carolyn Cassady in the unreleased "Heart Beat"). "To be frank, this character is not Loretta - It's what I and the director and everybody perceive her to be. What's sad is, I've known Loretta closely now for four or five months, and every day I say. 'Oh, shoot' because I missed something."

"Tommy Lee Jones had to dye his hair, too, to the reddish blond that still blinks through the gray in Mooney's hair ("Mooney" is what everybody in the world except his wife and Sissy Spacek call Oliver Vanetta Lynn Jr., it's a nickname left over from his moonshine-running days. The two Lorettas call him: "Doo" or "Doolittle," which is an older Kentucky nickname. If Mooney hadn't had to sign the marriage license, his wife would never even have heard of Oliver Vanetta Lynn Jr).

Jones is responsible for most of the legends growing up around "Coal Miner's Daughter," the kind of stories that crew members swap and then carry back to L.A. His reverse puzzles outsiders; some call him "uncommunicative" or even "inarticulate." "It could be a recent Brando affectation," shrugs one crew member. Others, more sympathetic, say he's a "wild man" who's trying to hold it in check.

The consensus is that Jones doesn't drink much, but he doesn't drink well, either. A couple of months ago, on location in Wise, Va., Jones managed to drive a pick-up truck onto the interstate median. That garnered him a DWI and a night in jail. About the same time, he set locals hair on end when his dog desecated in the lobby of the Wise Inn.

But nobody on the set has any quarrel with Jones' acting. The real Mooney hangs around, shaking his head and grinning. Spacek calls him "terrific." And in a burst of familial feeling, Apted has even written the dog, Travis, into a scene.

Young Loretta rocks in a corner of the living room, children at her feet. Mooney strides in from the kitchen, holding a copy of her record, and rolls onto the couch. "Honey, make hat dog get out of the house," he waves at small Elizabeth. She runs out, calling "Here, boy! come on, boy!" and we hear the screen door slam.

In the course of several hours' shooting. Travis balks numerous times, once bolting at the clacking of the sign board and leaving Elizabeth to back out, bewildered, and bang her head on the door frame. The children will forget not to look at the camera. Travis will run under the couch. The children will stumble over lines. Jones will call Elizabeth "darlin" and Spacek will enthuse, "That was wonderful, honey!" no matter what.

In the next room wait the props of the Lynns' early years: discount store poster-paintings of Jesus in Gethsemane, a box of Tinker Toys, unmade bunk beds, a china poodle on the mantlepiece, a teddy bear lamp, and a pair of Elizabeth's shoes, bronzed. The house, a couple of miles up the road from the ranch, smells of peeling linoleum and rotting wood; the front porch is roped off.

Outside, two members of the crew puzzle over a dilapidated chess board. Several have taken up Mooney's habit of whittling. Twenty feet away, the childrens' real mothers twist blades of grass in their fingers and roll up their jeans in the sun. There is a strong scent of resignation in the air; Apted is a deliberate director.

The only people who look at home here are the folks who live on the dirt road above Hurricane Mills, rocking on their porches above the daily procession. The Los Angeles crew members nudge their running shoes into the dirt; one wears rubber boots against snakebite. The British director's assistant is burning a brick red between her pink shirt and henna hair. From inside, Apted's slender voice can be heard: "Good doggie . . . bearing up? . . . this is likely to be tiresome this."

"How's it look for Sissy?" an assistant mutters into his walkie-talkie.

"Not too good - they were just putting in the first curl when I left."

Waverly, Tenn., to call Hurricane Mills by its nearest big town, is 10 miles north of I-40 west, at the sign of the Unusual Restaurant. It's the kind of long, hypnotic highway, green-lit as if underwater, where the patrol cars are tolerant and the white-tailed deer become traffic casualties.

Almost all the way up to Waverly is Loretta Lynn's Dude Ranch, a camping and trailer park with horseback riding, one of the Loretta Lynn clothing stores (where Spacek got her boots), the Loretta Lynn museum, a post office and the big house.

Behind the house, between the barn and the kennel, the cast and crew are celebrating the end of filming a week in advance. Levon Helm has brought the barbecue up from Arkansas, and his early '50s tapes of bluesman Sonny Boy Williams a shred the conversation. Travis has herded the guinea hens into a tree. Over at the barn, an L.A. greenhorn pours Sprite down a horse's throat. Half the guests are festooned with cameras; the other half, on cue, sling their arms around each other.

A Universal TV crew, trailing Spacek around, stops dead out front to pan the house. "Once from Butcher Holler, always from Butcher Holler," someone mutters, almost in awe.

There it is, the big house, symbol of the Loretta Lynn, empire and spiritual centerpiece of this movie.

Six white columns preen before the overblown farmhouse.A wrought-iron arch over the entrance reads, "Coal Miner's Daughter," like a benediction. The shrubbery is trimmed into the LL brand. Iron furniture dozes in the shade. In the vast green lawn, unabashed, struts a flock of pink plastic flamingos.

"You know," Spacek says suddenly. "I'm not ready to leave this."