Snowmobilers are the recreation group most likely to be killed in an avalanche, largely due to the activity of highmarking.
Highmarking is the recreational maneuver of attempting to reach the highest point of a snow-covered feature such as a mountain, on a snowmobile.
It refers to a specific activity in which the snowmobile operator's main goal is to accelerate and gain maximum elevation upon the face of a mountain before the machine reaches the top of the feature or upward progress is suddenly forced to diminish because of the grade of the feature, which gives the rider no choice but to turn around.
High marks vary in their degrees of difficulty depending on the pitch of a given ascent and conditions of the snow.
Highmarking involves serious personal injury risk factors, most notably the danger of the rider triggering an avalanche and becoming buried in the ensuing cataclysm.