"There's a vertical inconvenience ahead so we're going that way," says Allan the guide, pointing with his pole. "Do not go below me. Any questions?" In other words (mountain guides are masters of understatement): "There's a cliff down there so follow me or you're screwed." And with that Allan disappears. Whooping in anticipation, we follow him into the snow-cloaked forest.
Tree skiing at its best is supremely thrilling. Picture randomly spaced wooden giants rising from several feet of soft snow. Then tilt the entire scene to 30 degrees or more and imagine sweeping down through those trees at breakneck speed, thighs pumping as you plot a course on the fly. Part-skiing, part-freefalling, you bound over drops as if vaulting staircases scattered with white pillows.
The sensation is to the experience of most skiers – hard, crowded pistes – what white-water rafting the Zambezi might be to a Venetian gondolier. And nowhere is it better than at the Monashees, a fabled range of peaks deep inside British Columbia. It is the most demanding of 12 heli-skiing areas operated by Canadian Mountain Holidays (CMH), a company founded more than 40 years ago by an Austrian who realised what delights awaited airborne skiers. His vision has taken off and today CMH's domain covers an area a third the size of Switzerland; the Monashees alone is bigger than Greater London. The difference: it is populated by just 40 or so skiers.
It is a fist-bightingly expensive way to ski but such is the lure of the epic tree runs here that guests keep coming, even when they know money can't buy everything. For to ski is to dance with Mother Nature; satisfaction depends on her mood and she will always take the lead. When she's on form she'll leave your heart pounding, but sometimes she'll tread on your toes.
I arrive to find thick fog, which Dave the pilot can't fly through, so for three half-days we are grounded. There are, at least, worse places to be stuck: the luxurious but unpretentious Monashees Lodge, which is staffed by delightful young locals who ski and eat with guests, includes a bar (the weekly "kitchen parties" are legendary) and a rooftop Jacuzzi.
But the mountains are the draw and, just as people talk of early departures, Mother Nature gives us another spin – the fog dissipates and soon we're flying down Steep & Deep, one of almost 300 unmarked runs in the area. Powder at the top gives way to giant hoar crystals that tinkle like diamonds as they slough off the steep slope. At the bottom we exchange high-fives and wait for the Bell 212, which whips up a blizzard as Dave lands it inches from our knees. Then we soar to the next drop-off and do it all over again.
Even when resort skiing is good, powder hounds measure untracked skiing by the turn. At CMH, they measure it by the thousands of feet. In a week I ski 118,000 feet of virgin snow – more than in the previous 20 years. And even then, the tricky conditions mean I've only had a taste of what the Monashees can offer. This could turn out to be a financially ruinous glimpse of some of the best skiing in the world.
To read more and to see photos: independent.co.uk/cmh.
CMH offers heli-skiing from approx. £560 per day. A Monashees week costs £5,800, not incl. flights. Powder Skiing in North America are UK agents for CMH (psna.co.uk; 020-7736 8191)
* Rudechalets (who provide hipsters with ski and snowboard holidays in the French Alps) have launched a brand new pimped-up Chalet in Chamonix Mont-Blanc – the freesports capital of Europe, where activities include ice-diving, dog-sledding and heli-skiing. (08700687030; rudechalets.com)
* With the pound now so weak against the Euro, Norway compares favourably with the Alps for snowy breaks. There are few better places to get miles under your belt with cross-country skiing and the saunas are unbeatable. The resort of Geilo is a picture-perfect base with a good range of winter sports. Neilson (0845 070 3460; neilson.co.uk)
* Slovakia is firmly on the ski map. Budget flights, chalets that take weekend bookings and massive investment in infrastructure add up to a quality ski break. The Tatra Mountains and great cuisine are a bonus. Regent Holidays (0845 277 3317; regent-holidays.co.uk)
* Why not go on safari in the Alps? Based in Les Trois Vallées these new ski tours range from one day through to lengthy trips led by a guide, with luggage transported on to hotels. First Tracks (first-tracks.fr)