This is rubber country. Millions of slender trees at stiff attention in endless files across the flat, jungled land, oozing their lifeblood away for tires and soles, basketballs and galoshes.

It's Somerset Maugham country. Just the sort of place where the crusty teller of tales of the East set so many of his stories of colonial-era planters coping with the mysterious, dusky natives who served them. And with each other.

"Christ, how I hate this country," Maugham had Vesta Grange complaining in "Flotsam and Jetsam," a turn-of-the-century short story. "I hate that river. I hate this house. I hate that damned rubber. I loathe the filthy natives."

Plantation life has changed since Maugham wrote of the embittered Vesta and her planter husband. But the indefatigable traveler would have no trouble recognizing the trappings and customs, the pleasures and problems of an American planter, Park Chrestman, and his wife, Roscrana, who make their home on the vast Goodyear rubber estate here in northern Sumatra.

The orderly beauty. The endless ranks of rubber trees, each fitted with a little tin cup catching the dripping latex beneath chevrons of slashes.

The Dutch-styled white and green bungalows of the senior planters set in a manicured, nine-hole golf course along a narrow road lined with towering royal palms.

The "natives" of Vesta Grange's outcry, today as then moving quietly through the rubber trees, tapping and collecting the precious latex even before early sunlight pierces the dark, cool columns.

And the isolation. Twenty-two thousand people living and working on the plantation, but only a handful to talk to. The telephone, a hand-cranked set that reaches only to the nearest villages. Contact with the outside world through a crackling two-way radio set. No school for their two young daughters. Mrs. Chrestman teaching in the living room.

It's an unusual life. It was, even when there were more Westerners running the plantations of Sumatra, Borneo and Malaya back in Maugham's day. Today, there are very few and they tend to be people who are orderly minded and self-contained, who find life's satisfactions in themselves. The Chrestmans have been here for a year and they're still adjusting.

They recognize some parts of their lives in the Maugham stores. "There are the intensive, magnified relations between husbands and wives and with the other couples on the estate and the jostling for places in the pecking order which Maugham saw in the confined atmosphere," Mrs. Chrestman recalled the other day.

"When we got here, I expected to become an anachronism in the middle of the jungle. But the Indonesians on the staff have made us welcome and, in some ways, it's easier fitting into the life here than it would be in a suburb of Akron" (where Goodyear has its corporate headquarters).

"There are no hardships," she went on. "What I like most about it is the fresh air, the fresh food, learning a new culture and a new language. The only thing I really miss is more varied conversation. We're definitely restricted within a very small society here. I don't really know what's going on anywhere else."

Probably an exaggeration. Near her in the cool, high-ceilinged house as she spoke were stacks of New Yorkers, Economists and International Herald Tribunes. And a large shortwave radio tuned to the BBC.

In his teak-paneled office not far from the house, Chrestman, craggy and soft-spoken, looked over the low roofs of warehouses and processing mills. "Personally, I find estate life pleasant," he said. "It's not as static as it appears. We do get visitors from time to time. It's not that isolated an existence."

Chrestman, whose long years of experience in the rubber industry until coming to Sumatra were confined to administration and sales, said he conducts the estate "like any modern, corporate organization." His titles are managing director and vice president.

"He was up before daybreak," Maugham wrote of Vesta's husband, Norman Grange, "to take the roll-call of his labor and then walked over the estate to see that the tapping was properly done."

With 4.1 million rubber trees spread over 32,000 acres, Chrestman doesn't walk, or drive for that matter, over the estate's 150 miles of roads on a regular basis. Keeping track of the tappers, weeders and others of the 6,000 "labor" is left to foremen and supervisors. But Chrestman is at his desk at 7 a.m. six days a week.

In addition to the latex collecting, the plantation encompasses four small factories that produce latex concentrate, smoke rubber sheets, crepe sheets and crumb rubber, used mainly for tires. The estate is the most extensive in Sumatra and the largest owned anywhere by the Goodyear Tire and Rubber Co., which in turn is the largest rubber producer in the world.

Chrestman said he already has learned a great deal about the botanical and agricultural angles of the rubber industry. But he's yet to work out to his own satisfaction a role as the estate's community leader.

Speaking of the huge labor force and their families, he said, "I must admit I'm far removed and my concern should be to improve their living conditions. This estate is a long-term proposition and we want our people to stay and their children to progress in life."

Mrs. Chrestman, similarly, is trying to establish a community role for herself. "I refuse to become a memsahib," she said, "sitting up in the big house and smiling when the workers and their wives come by and doff their hats."

Yet, the social structure of the plantation, established under Dutch colonial rule, seems to demand a certain residual paternalism. The other evening, the Chrestmans presided over an Independence Day celebration at the estate clubhouse.

Mrs. Chrestman, with crisp, curly black hair and large brown eyes, wore a snug, black-lace blouse and batik sarong, the Indonesian national dress - "it's a gesture and it pleases the Indonesians" and placed a sequined crown on the head of a fashion show winner.

Chrestman, wearing a blue-flowered batik shirt, read a patriotic speech in Indonesian. "I wrote it myself, in English," he admitted with a smile later. "But it's the first time I've understood what I've said in Indonesian."

His only real complaint was similar to his wife's. "Of course, you must accept that you're too far from other social contacts, so social life is limited and restricted to some small number of people on the plantation."

The major social event is the daily 4:30 tennis game, when all the regulars meet on the club's two clay courts. Bridge and a little golf fill other gaps.

They're big on board games. Coffee tables, cupboards and shelves are stacked with backgammon, Othello, Monopoly, Scrabble and dozens of puzzles, useful in entertaining visiting wives of Indonesian staff members, most of whom speak little or no English.

"In most planters' houses," Maugham wrote, "there is not more than a shelf or two of books and for the most part they're detective stories."

Not so at the Chrestmans. Their compact library is crammed with hundreds of books, classics and best-sellers and a number of newly purchased volumes on Sumatran and Indonesian culture, history nad politics. Conversations are frequently interrupted for references to an atlas or an almanac.

"I never feel tied to the place as long as I have something fresh to read," Mrs. Chrestman said. "Unfortunately, we do run out because there are customs regulations on the number of books you're allowed to import."

Much of Mrs. Chrestman's time is taken up teaching 8-year-old Eugenia through a correspondence course. There are no other Western children on the estate. Daughter, Sadie, 10, goes to a boarding school in Malaysia, across the narrow Straits of Malacca.

"Genie has learned Indonesian quickly and she plays with the servants' children," Mrs. Chrestman said. But mother an child find the home teaching difficult. "It means Genie and I are together 24 hours a day, without the normal five-hour break most mothers and children get. It's not fair to either of us."

Occasionally, visitors come. One week recently they had two families, 11 people in all, as house guests. "You're a survival kit," Mrs. Chrestman, 37, said with a smile during drinks before dinner one evening.

"They began to talk over the whiskey and sparkler with which, following the Eastern habit, they celebrated the setting of the sun," Maugham wrote of the Granges and a rare visitor.

Similarly, when the sun casts long spidery shadows of giant rain trees across the rolling lawns, the white-uniformed butler, Sulaiman, pushes a trolley of drinks over the red-tile floor to the well-lit corner of the airy living room where the family generally gathers.

Two housekeepers maintain the spacious but simple three-bedroom bungalow and a cook prepares meals, mostly "from scratch," including brown bread and yogurt, Mrs. Chrestman said, because convenience items aren't available. Shopping is done at a small nearby village except for occasional visits to the port city of Medan for treats like canned ham, jam and cheese.

Except when Chrestman must make the two-hour drive to Medan to place phone calls to Akron or fly to Jakarta for consultations with government officials, he's at home for three meals a day.

Each morning, promptly at 9:30, he and his expatriate colleagues gather at one of their homes for coffee and cake. "It drives me bonkers," Mrs. Chrestman said. "They see each other eight hours a day and, when it's time for a break, they take it together. I "like one's own family," but she concedes that the household staff, like the lovely bungalow, "is one of the basic perks and one of the reasons for living here."

The visitor will probably be struck by some of the plantation characters, like the German-born company doctor, can't imagine what the Indonesian staff people must think."

The custom is a holdover from the days when all senior staff personnel were Americans. Nowadays, with all but the very top jobs held by Indonesians, privileges formerly reserved for expatriates are shared. These include membership in the club, where movies ("mostly spaghetti Westerns") are screened twice a week and bridge lessons are held, and use of the company-owned bungalow at Lake Toba, 2 1/2 hours away.

A stranger visiting the plantation for the first time is likely to have mixed feelings about the Chrestmans' lives here. On one hand, they're surrounded by extraordinary natural beauty and waited on by trained servants.

Mrs. Chrestman maintains that the servants, in turn, must be cared for a 60-year-old bachelor who's spent 18 years in Sumatra. He's a world-renowned authority on Sumatran butterflies and plays the cello. More fictional than some of Maugham's people.

But most visitors would go away most concerned about the feeling of isolation and limited social contact; too few people who see too much and know too much of each others' lives, who tend to magnify and dwell on petty irritants.

Although the Chrestmans have studied Indonesian and speak it passably, their regular contacts with local people are limited largely to the estate's elite.

"We can only entertain and mix with one social level at a time," Mrs. Chrestman said. "We'd like to try mixing a few levels together, but our early attempts proved disastrous and we-ve succumbed to the pressure of the inflexible social structure."

The Chrestman expect to remain on the plantation for another 8 or 10 years. Chrestman, 54, who comes from Spiro, a small Oklahoma village, will retire then and they plan to live in Australia, where he began his overseas experience in 1953, or possibly in Hawaii.

Mrs. Chrestman grew up in Australia's western Victoria on a remote sheep station owned by her father, Sir Magnus Cormack. "We were much more isolated there than we are here on the plantation," she recalled. The Chrestmans' rural backgrounds and years in India, Singapore and other foreign posts have no doubt helped them adjust to life here.

"I admit that I do occasionally miss going to the movies, the theater and the ballet," Chrestman said. "But whenever we go on leave, I gorge. And besides, if you live in Akron, or even New York or London, how often do you go to the theater or a concert?"