Extreme skiing is skiing performed on long, steep
(typically from 45 to 60+ degrees, or grades of
100 to 170 percent) slopes in dangerous terrain.
The sport is performed off-piste. Extreme skiing
as an English term has changed since the 80s when
the term "extreme skiing" was coined to now be
classified under Big Mountain skiing or
Freeskiing which encompasses all aspects and
methods of descending off-piste terrain.
Check out the video of Rex and Shane in action on
YouTube - rexpem.