Leslie Woit reveals that in Canada it's easy to get your off-piste adrenalin fix – If you know where to look

Ever wondered where those guys with the helmets, backpacks and fat skis are headed when they duck under the rope at the top of the lift? Beyond the usual blue, red and black run markers, there's a new colour on the piste map. It's called "slackcountry". Easy to get to, sometimes tricky to find, and always laced with danger, these days it's the crayon in the box that everyone wants to play with.

Slackcountry is Canadian slang for "easy-to-reach backcountry", the off-piste area just beyond the fences and ropes of a resort's boundaries. With its relentless snowpack and favourable wilderness-to-human ratio, western Canada is the spiritual home of slackcountry skiers.

British Columbia and Alberta are powder playgrounds, chock-full of glades, chutes and bowls close enough to deliver a quick-fix rush to experienced skiers and boarders.

By definition, these just-off-the-map forays can mean anything from a 10-minute traverse to a one-hour skin up with touring skis. Hiring a qualified local guide is the best way to enjoy the powder safely. In cases of extreme slackness, you could employ a snowcat, a helicopter, or even a snowmobile to get you to the right place at the right time. However you choose to get there, an avalanche transceiver, probe, shovel and the knowledge to use them are essential to any expedition to slackcountry.

Start with Whistler-Blackcomb, the daddy of powder. You can't go wrong in Flute Bowl, which is actually in-bounds, but it's a 45-60 minute hike before you ski. You'll also need to be a high intermediate or advanced skier to tackle it. The area is avalanche controlled, so pay attention to the signs and check the advisory. Nearby Symphony is a gateway to the massive backcountry surrounding Whistler-Blackcomb as part of Garibaldi Provincial Park. Whistler Guides ( whistlerguides.com) will show you the way.

While Whistler's slackcountry seemingly stretches to eternity, competition for first tracks can be robust. So consider the road even less travelled. By European standards, the British Columbia interior is virtually uninhabited.

Kicking Horse ( kickinghorseresort.com), Canada's "newest" resort, emerged just 10 years ago. With some serious steeps right off the lift, the Horse has been called the Jackson Hole of Canada. This season, the big lines, hucks and rollers have come even closer. Access to the aptly named Super Bowl is via a ski traverse trail from the top of the gondola. Slide across, pause to admire the panorama-packed Rockies, Selkirks and Purcells, sail down all the high-Alpine freshies you can handle – and it all feeds back to the lift station. With 15 new advanced and expert chutes, the entire bowl is now but a short pole away – and avalanche controlled, too.

What's special about Red Mountain ( redresort.com)? Trees, trees, trees. Each year this area of Kootenay, British Columbia, gets more than 20ft of dry snow and this season there's some additional freshly cut glades on an already impressive slackcountry menu. The new Grey Mountain area adjacent to the resort is accessed off the summit by a 20-minute skinning or snowshoe track. Smooth south-facing slopes deliver over 2,200ft of consistent vertical that's ideal for intermediate to expert skiers, with a no-sweat return to the lift. Although the terrain will be controlled by patrol, everyone must be equipped with transceivers, probes, shovels and a buddy. For extra frisson, book an overnight guided tour to the new Alpine Glory yurt.

Slackcountry aficionados will want to pay homage to Delirium Dive, the first "controlled extreme" terrain in Canada. Launched in 1998 at Sunshine, Alberta ( skibanff.com), this experts-only free-ride area is not marked for hazards – and these can be very real indeed. Just below the summit a 15ft rock band crowns the top of this high, north-facing cirque (there are also access stairs, no mean feat to negotiate in themselves). A five-minute hike beyond a gate that only opens with a working avalanche beacon earns you a 1,800-vertical-feet descent, then you can hop on the gondola and do it again. Or perhaps duck into Mad Trapper's for a well-deserved beer.

If this all sounds like too much hassle, there's a subset of slackcountry that may interest you.

Welcome to the slackest-possible-country. British Columbia has nearly 30 helicopter and snowcat services to east the skier's progress. They were invented here in the 1960s at CMH Heliskiing ( canadianmountainholidays.com) and Selkirk Wilderness Snowcat ( selkirkwilderness.com). See helicatcanada.com for a full list.

Best machine-fuelled Slackcountry

Now you can tick all your boxes in one go. Move over, Whistler, sit up, Vail. Two years ago Revelstoke ( revelstokemountainresort.com) took the ribbon for the longest lift-serviced vertical descent in North America and here you can sign up for the ultimate integrated holiday. It's the only resort in the world to offer lift-, cat- and heli-skiing from a one-stop shop amid 35-50ft of annual snowfall. Feeling expansive? Plump for the Ultimate ROC Pack, a four-day programme including a warmup day with a pro, followed by a day of cat skiing at Revelstoke, a heli-day in sumptuous gladed terrain with Selkirk Tangiers, and end on a worthy keeping-it-real note with a day of backcountry ski touring. Get too used to the good life and you may find yourself in the company of others who came for a week and got "Revel-stuck" in powder.

If you really want to go native, there's only one thing left: a sled. Sleds (no one under 40 calls them skidoos, let alone snowmobiles anymore) are the locals' own snow limos. Before investing in your own Arctic Cat, take a punt with Totally Awesome Adventures ( totallyawesomeadventures.com). They take private groups of skiers and boarders up into a vast expanse of Crown Land on the Pemberton Ice Cap, 20 miles north of Whistler.

Bring your skis or board, avalanche beacon, shovel and probe and expect to take on around a dozen runs of 2,000ft each day. You sled up beside the guide, shred down, and burn back up for another. It's called yo-yo-ing and it's as Canadian as maple syrup.

Off-piste riding, whether in the remote backcountry or just beyond ski area boundary, has a series of associated risks. It is always your responsibility to carry the right gear and just as importantly, to have the knowledge and experience necessary to use it effectively. A qualified guide is the safest option and one of the best routes to deep powder. See travelalberta.com and BritishColumbia.travel/ski