Off-piste

Backcountry skiing (US), also called off-piste (Europe) or out-of-area, is skiing in the backcountry on unmarked or unpatrolled areas either inside or outside a ski resort's boundaries. This contrasts with alpine skiing which is typically done on groomed trails benefiting from a ski patrol. Unlike ski touring, backcountry skiing can include the use of ski lifts including snowcats and helicopters. Recent improvements in equipment have increased the popularity of the sport.

The terms "backcountry" and "off-piste" refer to where the skiing is being done, while terms like ski touring, ski mountaineering, telemark, and extreme skiing describe what type of skiing is being done. Terms for backcountry skiing exist according to how the terrain is accessed, and how close it is to services. Backcountry can include the following:

Backcountry and off-piste skiing can be hazardous due to avalanche, exhaustion, weather, cliffs, rock fall, and tree wells. Avalanches result in about one fatality per month in the United States.

In Europe and Canada off-piste skiing is generally permitted at ski resorts. In the United States off-piste skiing may or may not be; regulations vary by ski area. Many ski resorts prohibit it outright and some simply post warning signs that skiers are leaving the patrolled ski area boundaries.

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Wikipedia