{{unreferenced, date=February 2011
Highmarking or High-Marking is a popular activity performed by snowmobilers in
mountainous
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher th ...
terrain, where the
snowmobile
A snowmobile, also known as a Ski-Doo, snowmachine, sled, motor sled, motor sledge, skimobile, or snow scooter, is a motorized vehicle designed for winter travel and recreation on snow. It is designed to be operated on snow and ice and does not ...
operator tries to ride as far up a steep mountain slope as possible, then turn around and come back down the hill without getting stuck, rolling the snowmobile or losing power.
This activity is extremely dangerous because optimum highmark terrain is typically in areas where
avalanche
An avalanche is a rapid flow of snow down a slope, such as a hill or mountain.
Avalanches can be set off spontaneously, by such factors as increased precipitation or snowpack weakening, or by external means such as humans, animals, and earth ...
danger is extremely high. Snowmobilers are the recreation group most likely to be killed in an avalanche, largely due to the activity of highmarking.
According to the
Utah Avalanche Forecast Center
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its we ...
, "Avalanche victims are almost exclusively backcountry recreationists--snowmobilers, climbers, snowboarders, snowshoers, skiers and hikers. Snowmobilers lead the list with twice the number of fatalities as any other activity."
Highmarking is the recreational maneuver of attempting to reach the highest point of a snow-covered feature such as a mountain, on a
snowmobile
A snowmobile, also known as a Ski-Doo, snowmachine, sled, motor sled, motor sledge, skimobile, or snow scooter, is a motorized vehicle designed for winter travel and recreation on snow. It is designed to be operated on snow and ice and does not ...
. 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.
A High mark begins when a snowmobiler leaves an established trail and fully accelerates; blazing his/her own trail upward toward the summit of a snow-covered mountain face, ideally lying at a 30-45% grade. As the terrain gets steeper, the machine's acceleration slows down. At the apex of the elevation gained, the rider must sharply turn 180 degrees and descend the feature. The height of the arching track left in the snow by a pioneering rider usually sparks competition within members of a rider's party, urging the rest to surpass the height of the original arch, thus initiating a competition. 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
An avalanche is a rapid flow of snow down a slope, such as a hill or mountain.
Avalanches can be set off spontaneously, by such factors as increased precipitation or snowpack weakening, or by external means such as humans, animals, and earth ...
and becoming buried in the ensuing cataclysm. According t "Highmarking accounts for more than 63 percent of the avalanche fatalities involving snowmobilers in North America." Highmarking should only be attempted by snowmobilers who are equipped with avalanche transceivers and accompanied by other riders capable of detecting a distress signal and rescuing a buried snowmobiler.