A snowmobile (or snow scooter, often referred to by enthusiasts as a 'sled' and in the Canadian north and Alaska as a 'snowmachine') is a land vehicle propelled by one rubber track with ski(s) for steering. They are designed to be operated on snow and ice, and require no road or trail. Most snowmobiles are typically powered by two-stroke gasoline/petrol internal combustion engines. Four-stroke engines are becoming more and more popular in snowmobiles. Even though they are not designed for it, snowmobiles will skim on top of water if the speed is high enough, as demonstrated by the annual snowmobile river drag race in Kautokeino, Norway. Summertime occupations for snowmobile enthusiasts can also involve drag racing on grass or even asphalt strips. People that drive them are commonly known as snowmobilers. Snowmobiles will beat most stock or aftermarket cars in a 0-100 drag race. An average 2007 snowmobile goes 0-60mph in 4 seconds flat.
The earliest snowmobiles were modified Ford Model Ts with the undercarriage replaced with tracks and skis. They were popular for rural mail delivery for a time. This early history  can be traced to Carl Eliason  in Sayner, Wisconsin with his first hand built model completed in 1923. He was granted a U.S. patent in 1927. Polaris Industries in Roseau, Minnesota, in the United States Midwest, was a pioneer in the production of purpose-built snowmobiles.
The relatively dry snow conditions of the United States Midwest made the converted model Ts and other like vehicles not suitable for operation in more humid snow areas such as Southern Quebec. This led Joseph-Armand Bombardier of the small town of Valcourt in Quebec, Canada, to invent a different caterpillar track system suitable for all kinds of snow conditions. Bombardier had already made some "metal" tracked vehicles since 1928, but his new revolutionary track traction system (a toothed wheel covered in rubber, and a rubber and cotton track that wraps around the back wheels) is his first major invention and led him to become an industrialist. He started production of a large, enclosed, seven-passenger snowmobile in 1937, the B-7 and introduced another enclosed twelve-passenger model, the B-12 in 1942. The B-7 had a V-8 flathead engine from Ford Motor Company. The B-12 had a flathead in line six cylinder engine from Chrysler industrial, and 2,817 units were produced until 1951. It was used in a lot of applications, such as ambulances, Canada post vehicles, winter "school buses", forestry machines and even army vehicles in world war 2. But Bombardier, all his life, had always dreamed of a smaller version, more like the size of a moto or scooter.
It was only in 1959, when motors became lighter and smaller than before, that Bombardier invented what we know as the modern snowmobile in its open-cockpit one- or two-person form, and started selling it as the "Ski-doo". He was lead in 1954 by Brothers Edgar and Allen Hetteen and a friend, David Johnson of Roseau, Minnesota. Then company known then as Hetteen Hoist & Derrick Co. became known as Polaris Industries. Competitors sprang up and copied and improved his design. In the 1970s there were hundreds of snowmobile manufacturers. From 1970 to 1973 they sold close to two million machines, a sales summit never since equalled. Many of the snowmobile companies were small outfits and the biggest manufacturers were often attempts by motorcycle makers and outboard motor makers to branch off in a new market. Most of these companies went bankrupt during the gasoline crisis of 1973 and succeeding recessions, or were bought up by the larger ones. Sales reached a peak of 260,000 in 1997 and went down gradually, influenced by warmer winters and the use during all four seasons of small one- or two-person ATVs. Bombardier Recreational Products, a former division of the first company, still makes snowmobiles, outboard motors, personal watercraft, and ATVs. The snowmobile market is now divided up between four big makers: Ski Doo, Arctic Cat, Yamaha, and Polaris. Modern snowmobiles can achieve speeds in excess of 193 km/h (120mph). (Racing snowmobiles reach speeds in excess of 241 km/h [150mph]).
Snowmobile with a single rider Snowmobiles are used by reindeer herders. Courtesy altapulken.noSnowmobiles are widely used in arctic territories for travel. However, the small population of the Arctic areas makes for a correspondingly small market. Most of the annual snowmobile production is sold for recreative purposes much further south, in those parts of North America where the snow cover is stable during the winter months. The number of snowmobiles in Europe and other parts of the world is relatively low, though they are growing in popularity.
In recent years, Andrew Horn of Anchorage, AK has been lighting up the area with his own version of freestyle snowmachining. A distinct subculture has risen up around aggressive, deep powder, and back-country snowmobiling. Gaining popularity in the mainstream mostly because of movies such as the "Slednecks" series, riders of this type ride very aggressively on terrain such as mountain slopes, hills, mountain bowls and any other place where very deep powder snow can be found. Deep snow is sought because it allows for "carving," or throwing the snowmobile off axis or on is side and making circles or maneuvering the sled in a forward motion in the same fashion. Hills with deep snow are sought after for "hill climbs," or "highmarking" which involves riding up very steep slopes, often with the track but not skis touching the snow. Cornices and other kinds of jumps are sought after for aerial maneuvers. Riders are often very zealous in their search for un-tracked, prime terrain and are known to "trailblaze" or "boondock" deep into remote territory where there is absolutely no visible path to travel on. Some riders use extensively modified snowmobiles, customized with parts such as handle bar risers, handguards, custom/lightweight hoods, windshields, and seats, running board supports, and numerous other modifications that increase power and maneuverability. Many of these customizations can now be purchased straight off the showroom floor on stock machines.
The environmental impact of snowmobiles has been the subject of much debate. Most snowmobiles are still powered by two-stroke engines, although Yamaha has been using four-strokes since 2003. In the last decade several manufacturers have been experimenting with less polluting motors, and putting most of them in production. Yamaha and Arctic-Cat were the first to mass produce four-stroke models, which are significantly less polluting than the early two-stroke machines. Bombardierís SDI two stroke motors emit 60 percent less pollutants than previous carburated 2-strokes. Polaris is using a fuel-injection technology called "Cleanfire Injection" on their 2 strokes. The industry is also working on direct injected "clean two strokes" which are actually an improvement on carbureted four strokes in terms of NOX emissions. Ski-Doo is the only approved 2 stroke to drive in Yellowstone National park, the park awarded them for their advanced research into SDI and DI technologies.
On November 4, 2004, the National Park Service of the United States approved a Finding of No Significant Impact (FONSI) for the Temporary Winter Use Plans and Environmental Assessment for Winter Use in Yellowstone and Grand Teton National Parks and the John D. Rockefeller, Jr., Memorial Parkway. The Final Rule implementing this decision was published in the Federal Register on November 10, 2004. Recent tests showed that snowmobiles have little or no environmental impact on the environment, this is due to them running when its extremely cold out which prevents the exhaust from becoming smog.
This decision allows 720 snowmobiles per day in Yellowstone, all commercially guided. In Grand Teton National Park and the John D. Rockefeller, Jr., Memorial Parkway, 140 snowmobiles would be allowed. With minor exceptions, all snowmobiles would be required to meet NPS Best Available Technology (BAT) requirements. The plan will be in effect for three winters, allowing snowmobile and snowcoach use through the winter of 2006-2007.
In the National Parks, snowmobiles are permitted only on roads that automobiles use during the summer, or designated trails.
Snowmobilers in Canada and the United States spend over $27 billion on snowmobiling each year. This includes expenditures on equipment, clothing, accessories, snowmobiling vacations, etc. It is very often the only source of income for some smaller towns that rely solely on tourism during the summer and winter months, while it still has a major economic impact on larger cities and towns as well.
Loss of control can readily cause extensive damage. A common accident entails a rider losing his or her grip on the machine, which often results in the now rider-less sled crashing into objects like trees.
People die every year when they crash into other snowmobiles, automobiles, pedestrians, or trees or fall through ice. Around 10 people a year die in such crashes in Minnesota alone with alcohol a contributing factor in many (but not all) cases. In Saskatchewan, 16 out of 21 deaths in snowmobile collisions between 1996 and 2000 were alcohol-related.
Industrial-type Snowcats for grooming cross-country ski trails and right of way maintenance are also made. They are large enclosed vehicles which can carry passengers and cargo, and tow sleds. Unlike the recreational snowmobile, they are completely tracked and have no skis in the front. They are powered by strong 4-, 6- or 8-cylinder diesel or gasoline engines.
Grass drags are held every summer to fall (autumn), with the largest event being Hay Days in Lino Lakes, Minnesota. Hay Days has always been the first weekend following the Labor Day Holiday. The World Championship Watercross or Snowmobile skipping races are held in Grantsburg, Wisconsin in July. The Snocross racing series, where snomobiles race on motocross-like courses during the winter season in Northern United States and Canada, is very popular. There are also races called Ice Ovals. This is kind of like nascar on a snowmobile.A major oval event each winter is the Eagle River World Championship Derby held in Eagle River Wisconsin.
Typical Snowmobile A 1997 Arctic Cat ZR 580 Snowmobile