High up in the Ulley Valley, the late afternoon air is thin and bitterly cold. Hunkered down in a rocky cleft, Tsewang Namgyal scans the snow-dusted slopes with battered binoculars, his prematurely lined face testament to the harsh, high altitude environment of Ladakh. Here in India's Himalayan north, tracking the "grey ghost" has always been a physically demanding undertaking.

"Twice in my life I've seen a snow leopard," says Namgyal, shoehorning his body further between two moss-covered boulders to light a cigarette. "People call it the 'grey ghost' because it comes and goes and nobody knows it's there. In the Ladakhi language we also call it the ' shan'. People have lived here all their lives and have never seen one, so I guess I'm lucky."

With wisps of smoke rising from a couple of mud brick buildings on the valley floor below, a herder rounds up livestock, the sound of human cries and yak bells faint on the breeze. The sinking sun bathes the flanks of nearby ridges in fleeting warmth, as dark clouds roll across the serrated, snow-clad horizon.

Namgyal calls a halt to today's big-cat quest.

WATCH a snow leopard filmed in Ulley by WildFilmsIndia

"Ladakh is the land of many passes," says the guide, picking his way down a scree-covered slope with ease. "In the past they said the land here was so harsh and the passes so numerous that only the best of friends or the worst of enemies would visit you. At over 4,000 metres, we should still respect the weather."

Namgyal leads the way down into the village of Ulley along a sandy, dung-littered path. Suddenly, he bends over to examine the ground.

"Fresh snow leopard tracks and scat," he says, pointing out a line of distinctive, four-toed prints intermingled with those of humans and yak. "From last night. The ghosts are here, passing through the village while everyone sleeps."

What the African lion is to the plains of the Serengeti so the snow leopard is to the elevated, rugged landscapes of Central Asia. From the Himalayas in the south, across the Qinghai-Tibet Plateau and the desolate massifs of Central Asia to the Altai and Sayan mountains of Russia, in the north, this majestic animal lives in some of the harshest conditions on Earth.

While the snow leopard is perhaps the least well known of the world's nine big cats, it is clearly a master of disguise. With its smoky, grey-yellow fur dappled with dark rosettes and spots, it is superbly camouflaged for life among rocks and snow fields. In fact, the snow leopard is perfectly adapted to its environment in many ways. Its tail, which often makes up three-quarters of the animal's total length, provides balance and agility in treacherous terrain and can cover the leopard's body, mouth and nose in freezing temperatures. Large nasal cavities and well-developed lungs counter the oxygen deficiency of high altitude air; wide, fur-covered feet act as natural snowshoes; and small ears minimise heat loss.

"Snow leopards are apex predators," says Dr Tsewang Namgail, director of the Snow Leopard Conservancy - India Trust (SLC-IT), an NGO based in the Ladakhi capital, Leh. "They are barometers of a healthy ecosystem. But, unfortunately, humans don't always appreciate such health."

Humans threaten the snow leopard's existence across much of its range. With numbers thought to have decreased by 20 per cent over the past two decades, there may be as few as 3,500 animals left in the wild, spread across an area of 2 million square kilometres (the size of Greenland).

Ladakh, a high altitude desert that borders Tibet to the north, is home to most of India's 500 snow leopards. The main threats here are from hunting, a diminishing food base and escalating contact with the humans who share their habitat. The mountains of Central Asia were once well-stocked with wild sheep, antelope and ibex, but in many areas these prey species have suffered serious declines or disappeared altogether.

"Starved of their normal food, leopards have come to see livestock as an easy meal," says Namgail. "This problem is compounded by the fact that more Ladakhi children are now going to school. This means fewer people tending animals, leaving them vulnerable to attack."

The following morning, the village of Ulley comes to life beneath a cloudless sky. Local farmer Tsewang Norboo takes a break from chopping firewood to retrieve a leather-bound book. On every other well-thumbed page, photos of carcasses depict local leopard kills in graphic bloodiness.

"Honestly, I used to hate snow leopards," says Norboo, who has lived in Ulley all his life and has been herding yaks, cows and dzo (a yak-cow hybrid) since he was 17. "They would often hunt and kill a lot of our animals. My family and I didn't have much choice but to hunt them back. It was them or us."

Thanks largely to the efforts of the SLC-IT, those days are over. Founded in 2003, the Indian NGO's main aim is to reduce human-snow leopard conflict. One solution, which has already seen livestock kills drop significantly, has been to provide doors, door frames and wire mesh to Ladakhi villagers, to render their animal pens leopard-proof. The NGO has also started an insurance programme - hence the leather-bound record book - that compensates farmers when their animals are killed by the big cats.

"Sometimes it's little things like this that really make a big difference to people's lives," says Namgail.

"We can come home at night now instead of guarding the enclosures," says Norboo. "And we get the compensation for animal losses in good time. When we applied to the government it would take years before we even saw a rupee."

Bordered by two of the world's highest mountain ranges - the Himalaya and Karakoram - and bisected by the mighty Indus River, Ladakh is a dramatically beautiful region. A land of misty valleys, golden-leaved poplars, remote gompas (monasteries) and high altitude lakes, it is influenced by Buddhist culture and is known by many Indians as Little Tibet.

Given Ladakh's natural and cultural charms, it comes as little surprise that the SLC-IT's key contribution to snow leopard conservation involves tourism.

"We knew that many people who live in remote Ladakhi villages such as Ulley have a day-to-day struggle to survive," says Namgail. "We also knew that for intrepid tourists, the opportunity to immerse themselves in Ladakhi culture while tracking a wild snow leopard was a huge attraction. This is why we started our Himalayan homestay programme."

In return for training in hospitality, hygiene and housekeeping, and items such as blankets and bed sheets, participating homestay households have to agree to stop killing snow leopards, even if their livestock is taken. Ten per cent of the income generated by the homestay is paid into a fund for general environmental protection while many villagers have been taught to make traditional clothing and handicrafts, which they can then sell as souvenirs.

With their in-depth knowledge of the local landscape and fauna, many villagers double up as guides and trackers for the tourists, who generally pay about 500 rupees (HK$60) per night.

The SLC-IT has homestays in more than 40 villages across Ladakh and is planning to expand the programme, as well as enlist villagers in snow leopard surveys.

"We still need to do some streamlining," says Namgail. "But Ladakhi people are now receiving tangible benefits from their willingness to co-exist amicably with snow leopards and other wildlife. Cat sightings are on the increase. It's a big step forward."

"Many of my yaks are missing tails and we still get some leopard kills," says Norboo. "But now we let the leopard finish its meal in peace. For us, a live leopard is now better than a dead one.

"Thankfully, I can now say that as a farmer and a Buddhist."

Getting there: Air India, Cathay Pacific and Jet Airways fly between Hong Kong and New Delhi. Air India, Jet India and GoAir all make the 40-minute flight between the Indian capital and Leh. Homestays in Ulley and other Ladakhi villages can be booked through Himalayan Homestays (himalayan-homestays.com). Mystic India (mysticindia.co.uk) offers a range of classic and tailor-made Ladakh tours, including snow-leopard-focused packages.