Skiing the HIGH ROAD : Between resorts at Chamonix and Zermatt, winding through France, Italy and Switzerland, is an 81-mile Alpine trail of powder and ice that demands both endurance and technical skill

Far below the mountain’s peak the skier glided down a snow ridge, carving S-curves through the sparkling powder. Tucking into a crouch, he schussed headlong down the slope and onto the flat.

The brisk, early morning ski run was a sensuous plunge through spring sunshine and crisp mountain air into a miles-wide bowl of new-fallen snow.

It was the sort of experience that makes the 81-mile Haute Route, through the western Alps, the best-known, most prestigious high-mountain ski tour in the world.

The Haute Route truly is a “high road,” averaging nearly 10,000 feet of altitude as it reaches through Switzerland, France and Italy, linking Europe’s two most famous peaks and the pricey resorts of Chamonix and Zermatt.

Mountain huts along the way offer inexpensive lodgings, as well as food and drink flown in by helicopter at prices 10% to 60% above normal.

The costs are heavier in the area of physical exertion, too. An end-to-end journey on the Haute Route demands seven to nine days of strenuous up-and-downhill skiing over powder, ice and every snow condition imaginable.

The challenge discourages--and sometimes endangers--many skiers who have only cross-country or downhill experience.

“Don’t underestimate the effort demanded, the technical level,” said a spokesman for the Compagnie des Guides in Chamonix. The average distance of the climbs each day, during four or five hours at a normal touring pace, is 3,300 to 4,000 feet.

The Haute Route originally developed as a summer hiking trail more than a century ago.

During the summers of 1860-62 British mountaineers and local guides charted a walking route over the passes between Mont Blanc and the Matterhorn, calling it the High Level Route.

Not long after skis were introduced to the Alps late in the 19th Century, mountaineers began trying the Haute Route in winter.

In 1911 a party skied to Zermatt from a village below the Great St. Bernard Pass. Between the world wars other skiers extended the route to its present itinerary: Chamonix to Saas Fee via Zermatt.

Rained out of Chamonix, our party of six skiers and two guides skipped Argentiera and Champex and began at Bourg St. Pierre, where those first skiers had started three-quarters of a century before. Fitting synthetic traction skins to our skis we began a slow, steady climb into the Alps.

All day we toiled higher into the mountains, zigzagging up the steep slopes, and finally stopped for the night in a small mountain hut.

Resuming the climb the next morning, we soon became lost in thought and the effort demanded by the steepening route. It was so steep that we took off our skis to scramble the last 100 yards to the first pass. It was a bitterly cold, wind-whipped passage into another world.

On the far side the sun shone through scattered clouds and mountain walls blocked the wind.

The snow was soft and deep. Stripping skins from skis, we fairly flew, whooping and yelling, chasing one another down through the virgin powder onto the broad head of a glacier. From there we could see the next pass and the long, uphill approach.

Thus unfolded the yin and yang of ski touring: a slow, strenuous climb in quiet solitude up one side of a pass, then a fast, effortless descent in boisterous camaraderie down the other. A cool, easy glide down a mileslong glacier one day, then a hot, labored ascent of a seemingly endless snow field the next. Always, at the end of each day, appeared another very welcome mountain hut.

Forbidding and fortress-like outside, the stone huts along the Haute Route exude warmth and friendliness inside. In the large ground-floor common room, skiers relax around long tables and dine and visit under the glow of gas lamps.

From a kitchen, the hut guardian serves dinners at night, usually soups and stews, and continental breakfasts in the morning, and sells everything from schnapps and coffee to chocolate bars and post cards.

In the upstairs dormitory, a pillow and two folded blankets mark each sleeping space on long, shelf-like double bunks that stretch wall-to-wall under the roof. You wash wherever you can, sometimes outside, where the washroom is often at the end of a snowy path.

While the dinner menu, the price of wine and the weather changed from one hut to the next, on our trip the daily navigation remained constant.

Each evening after dinner the guides spread maps over the table, plotted the course to our next destination and recorded the information.

If trapped in fog or falling snow we would be able to “feel” our way back to the hut following reverse compass headings and measuring the distances in rope lengths.

On the last day out, breakfast was served early. We filled thermos flasks with hot, sweet tea and left by starlight for the spectacular run over three passes and down the flank of the skyscraping Matterhorn.

Headlamps glimmering, we breezed down to a glacier plateau, put skins on skis and began yin-yanging over the mountains. Bad weather was coming, and we wanted to beat the storm to Zermatt.

Five hours and two passes later we stopped for lunch in a bright, sunny bowl at the head of the Tsa de Tsan glacier, the only place where the Haute Route crosses through Italy.

In two more hours we reached the third pass and the hoped-for magnificent view of the Matterhorn. But ominous leaden clouds had already hidden the top of the rock giant and were fast dropping toward us.

From this pass the Haute Route falls more than a mile to Zermatt. Between the fluffy powder on top and the wet slush at the bottom lay a treacherous blend of snow conditions. Delightful at first, the descent grew into a fatiguing challenge as we lost altitude and the snow deteriorated.

In the valley the trail flattened into an easy skate over increasingly wooded terrain and suddenly dropped onto a snowy road. A few minutes later we caught up to civilization on the terrace of a lively restaurant next to the crowded ski slopes above Zermatt.

Ordering a round of beer, we toasted each other, celebrating the wild descent, then settled back to bask in the afterglow of the best adventure the Alps have to offer.

Ski touring requires both strength and endurance, much more than for an average day of downhill or cross-country skiing. Before attempting the Haute Route you need to practice ski touring, which combines elements of cross-country and downhill skiing, and mountain climbing on skis.

If you don’t have enough mountaineering experience to avoid avalanche areas, rescue someone from a crevasse or navigate through a snowstorm, you have no business being on the Haute Route without a guide.

Ill-fitting boots or inadequate clothing can cause serious trouble on the Haute Route, if bad weather sets in.

The Haute Route is best skied in the spring, from mid-March to late May.

Guided tours, for private or scheduled tours, run about $60 to $90 a day, including food, lodging and transportation (cable cars, buses) but excluding personal equipment. Non-guided groups face $15 to $30 in hut expenses per person a day, depending upon the amount of food taken along.

Mountaineering groups may offer guided tours on the Haute Route, but many tours follow variations that avoid difficult but rewarding passages on the classic route, so check tour itineraries closely.

Here are guide services that take skiers onto the Haute Route, usually with English-speaking guides available:

--Mountain Travel, 6420 Fairmount Ave., El Cerrito, Calif. 94530, toll-free (800) 227-2384 or (415) 527-8100. Offers tours for groups.

--Gibson Tours Ltd., 210 Piccadilly Downs, Lynbrook, N.Y. 11563, (516) 599-6693.

--Compagnie des Guides, Maison de la Montagne, 190 Place de l’Eglise, 74400 Chamonix, France. Offers scheduled and private tours.

--Zermatt Mountain Guides Assn., Mountain Guide Office, CH-3920 Zermatt, Switzerland. Offers guides for private tours.

Trains link Geneva International Airport to Chamonix and Zermatt and also operate between the two resorts. Connecting buses serve Saas Fee and several small towns near the Haute Route. If you are planning to arrive by private car and the group is large enough, it may be more economical and is certainly more convenient to return to the cars by taxi.

Chamonix and Zermatt offer a broad choice of lodging, from dormitory beds at $8 to $16 a night to four- and five-star luxury hotels.

For a list of hotels and prices in Chamonix, write to the Office du Tourisme, Place de l’Eglise, 74400 Chamonix, France. The central booking office at the Office du Tourisme can make room reservations by mail.

For a list of hotels and prices in Zermatt, write to the Tourist Office, CH-3920 Zermatt, Switzerland.

For more information on travel to Switzerland, contact the Swiss National Tourist Office, 250 Stockton St., San Francisco 94108, (415) 362-2260.

For information on travel to France, contact the French Government Tourist Office, 9454 Wilshire Blvd., Suite 303, Beverly Hills 90212, (213) 271-6665 or (213) 272-2661.