Designed for travel on snow, it consisted of a sleigh body mounted on a framework that held an engine, a drive-shaft system, and runners.
These used a flexible belt rather than interlocking metal segments and could be fitted to a conventional car or truck to turn it into a half-track, suitable for use over soft ground, including snow.
Bushnell company in Aberdeen, South Dakota, built an open two-seater "motor-bob" out of an Indian motorcycle modified with a cowl-cover, side-by-side seating, and a set of sled-runners fore and aft.
[16] Carl Eliason of Sayner developed the prototype of the modern snowmobile in the 1920s when he mounted a two-cylinder motorcycle engine on a long sled, steered it with skis under the front, and propelled it with single, endless track.
This led Joseph-Armand Bombardier from the small town of Valcourt, Quebec, to invent a different caterpillar track system suitable for all kinds of snow conditions.
The machine had a track mounted beneath a snowboard like base, on top of which were an enclosed engine with motorcycle like seat and fuel tank.
The Whistler Blackcomb ski resort is testing Taiga's electric snowmobiles with lower noise,[24] and similar vehicles exist.
Snowmobiles are capable of moving across steep hillsides without sliding down-slope if the rider transfers their weight towards the uphill side, a process called side-hilling.
Riders often search for non-tracked, virgin terrain and are known to "trailblaze" or "boondock" deep into remote territory where there is absolutely no visible path to follow.
However, this type of trailblazing is dangerous as contact with buried rocks, logs, and frozen ground can cause extensive damage and injuries.
Some riders use extensively modified snowmobiles, customized with aftermarket accessories like handle-bar risers, handguards, custom/lightweight hoods, windshields, and seats, running board supports, studs, and numerous other modifications that increase power and maneuverability.
Sno-cross oriented snowmobiles often have an engine size cap of 440 or 600 cc, but lighter machines with redesigned stances, formats, and weight control have produced extremely fast and quickly accelerating race sleds.
Edgar and Allen Hetteen and David Johnson of Roseau, Minnesota, invented what we now know as the modern snowmobile in 1955–1956, but the early machines were heavy (1,000 lb or 450 kg) and slow (20 mph or 32 km/h).
Sales rebounded to 260,000 in 1997 but gradually decreased afterward, influenced by warmer winters and the use during all four seasons of small one- or two-person ATVs.
Engine and transmission combination are designed to deliver optimum power to pull or carry large loads while top-end speeds are kept below 52 mph (84 km/h), depending on the model.
[33] As a result of their inherent maneuverability, acceleration, and high-speed abilities, skill and physical strength are both required to operate a snowmobile.
If the rider falls off, the loss of control can easily result in the snowmobile colliding with a nearby object, such as a rock or tree.
Each year, riders are killed by hitting other snowmobiles, automobiles, pedestrians, rocks, trees, or fences, or falling through thin ice.
Inability to hear the sound of an oncoming train over the engine noise of a snowmobile makes this activity extremely dangerous.
Risks can be reduced through education, proper training, appropriate gear, attention to published avalanche warnings and avoiding drinking alcohol.
Depending on jurisdiction, there may be penalties for driving outside permitted areas, without an approved helmet, without a driver's license, with an unregistered snowmobile, or while under the influence of alcohol or other substances.
[42] In another example of regulation, only four-stroke snowmobiles are allowed in Yellowstone National Park since a bylaw was recently passed to minimize CO2 emissions and noise.
In 2005 the US Forest Service published a Travel Management Rule[44] for off-highway vehicles, strengthening the implementation of Executive Orders issued in the 1970s.
In 2015, following a decision in a lawsuit brought by Winter Wildlands Alliance against the Forest Service, the rules were extended to snowmobiles, referred to as an over-snow vehicle (OSV).
[45] National Forests with sufficient snow for winter recreation are now required to designate where OSVs are allowed to travel and where they are prohibited.
[50] Arctic Cat in 2005 introduced "Silent Track technology" on touring models such as the T660 Turbo, Bearcat, and some M-Series sleds.
Local and state authorities have set up checkpoints on high-traffic trails, checking for excessively loud systems and issuing citations.
Typically these systems are installed on two-stroke powered machines (giving the distinctive "braap" sound); however, in recent years aftermarket companies have released silencers for four-stroke models as well.
Often this is the only source of income for some smaller towns, such as Bralorne, British Columbia, that rely solely on tourism during the summer and winter months.
[60] In northern North America, historically, isolated communities depended on dog sledding and snowshoeing as their primary method of transportation for hunting during the winter months.