Winter visitors to the Alps would be surprised to discover what's hidden under all that snow, says Stephen Wood

Skiers take only a short lease on the Alps. For the winter months, soon to end, they have the run of the mountains, courtesy of the income they bring to the economy of the villages and valleys. Their counterparts who follow in summer – the walkers and climbers, tennis-players and mountain-bikers – take up an even shorter residence on the same slopes. Tourism may have eroded local traditions, and changed the meaning of "the seasons"; but the farming families who have worked the land for centuries remain the freeholders of the mountains.

Consider, for example, the Portes du Soleil, the huge ski area (it has more than 600km of linked pistes) which winds along the northern Alps, straddling the border between France and Switzerland. Avoriaz, one of its two pivotal points, is a purpose-built ski resort with little but high-rise apartment blocks, hotels and restaurants, and other winter-sport holiday facilities; the second, Châtel, also in France, is a "village" so bloated that it provides 20,000 beds for visitors. But the smaller settlements of the Swiss sector – and even the quite substantial Champéry – still reflect mountain tradition.

Here, it is rare to hear and smell cattle in their winter quarters, unlike in many Austrian resorts. Yet beyond the bars, sportswear shops and other stamping grounds of skiers, cows still shuffle and snuffle in wooden sheds, feeding on hay and cereal foods. The pastures which provide their daily diet in summer are also hidden from skiers, by a cover of snow. Few skiers know – still less care – what lies beneath it: most would be surprised to discover, for example, that one of the pistes at Val d'Isère is, in summer, a road running down to a car park. But those who choose to look will find evidence in the ski area above Champéry of the survival – and sometimes revival – of artisanal, Alpine dairy-farming.

Jean-Pierre Marclay and his son still work the family farm down in the valley on the outskirts of the village. It lies near Grand Paradis, the bottom of a lovely red run which drops down the southern extreme of the Champéry-Les Crosets sector of the Portes du Soleil. In winter, however, Marclay spends much of his time in the mountains, on the pasture he owns near the top of the same piste. This land had been owned by his family for two generations; but it was sold a quarter of a century ago to a company planning a major ski development. Nothing came of that, and Marclay bought the land back in 1986. Now the old, summer farmhouse, behind the Pointe de Ripaille, is a restaurant, Alpage Lapisa, which serves good, simple food to skiers and also rents rooms to them upstairs.

Across from the restaurant's terrace is a huge mound of snow, beneath which lies Marclay's cheese cellar, a richly aromatic place where the previous summer's production – wheels of cheese about a foot across, and of varying thickness – matures on wooden shelves for up to seven months.

Marclay's 35 brown Simmental cows spend the winter in the valley, the milk they produce being sold as feed for veal calves. Once, cheese was made down there, too; but food-hygiene regulations made running a fromagerie in close proximity to the cattle prohibitively expensive. Come mid-June, however, the herd moves up to the rich pasture, to graze on grass, chives and wild rhubarb. With the distraction of winter jobs (among them using his snowmobile to tow skiers up the mountain) behind him, and with his cows outdoors, Marclay can indulge his passion for making cheese the old way, heating and separating the milk in a massive copper kettle over a wood fire. The cheese is – sadly, for it tastes so good in its "raw" state – made to melt in a pan rather than the mouth: it is produced expressly for raclette, the rich, gooey staple of the Swiss Alps.

The fromagerie is open to visitors, bringing summer business to the Alpage Lapisa. And the same synergy lies behind the creation of a modern equivalent of Marclay's operation, on the other side of the Champéry-Les Crosets ski area.

By the standards of the Portes du Soleil, the village of Champoussin is close by; but it still takes a good hour of skiing to traverse the valley face and reach the bottom of the Aiguille des Champeys chair-lift. On one side of it lies Gaby Gex-Fabry's restaurant; on the other is his fromagerie, La Ferme à Gaby. Opened in 1999, it makes goats' cheese, of which it sells 15 varieties in the farm shop. The flock of 42 goats lives all-year-round in the shed, trotting into the mechanised parlour every day at 5pm to produce about 150 litres of milk. Next door in the squeaky-clean dairy, all stainless steel and white plastic, the cheesemaker (and herdsman) Denis Monier-Benoit moulds the familiar, cylindrical goats' cheeses, to be sold fresh or after maturing for between one and five weeks. He also makes a firmer tome cheese, which neither tastes nor smells as mild as it looks.

By comparison with Marclay's fromagerie, which expresses his almost romantic attachment to the mountain way of life, La Ferme à Gaby is more business-like: it even has a "sponsored goat" scheme. For a payment of Sfr500 (£210) sponsors (or, more usually, their children) can name a goat, and enjoy a dozen annual dinners for two in Gex-Fabry's restaurant. Subsequent identification of their goats is something of a problem, except for the sponsor of Arvine, who stands out from the rest of the beautiful brown/black flock because of the lighter coloured patch on her mouth; even Monier-Benoit says he has difficulty recognising the goats individually, except by their udders.

Leaving La Ferme à Gaby with a souvenir – unusually for a skier, because of the mess soft cheese can make of a pocket in a fall – I headed back up the mountain to ski the long descent to Morgins, near the French border, stopping along the way at Albert Rey-Mermet's bar/ restaurant at Tovassière. He, too, opens up a fromagerie in summer, when his herd comes to pasture. And Rey-Mermet maintains mountain traditions in the grand manner: his 55 animals are Hérens, Switzerland's treasured breed of black, fighting cows.

Further information on the Portes du Soleil at, and on Switzerland from the Switzerland Travel Centre (freephone 00800 100 200 30) or