Numerous people had similar ideas. Edgar and Allen Hetteen and David Johnson of 
Roseau, Minnesota were among the first to build a practical snowmobile in 
1955-1956, but the early machines were heavy (1000 lbs or 450 kg) and slow (20 
mph or 30 km/h). Their company, Hetteen Hoist & Derrick Co., became Polaris 
Industries, a major snowmobile manufacturer.[4]. It was only in 1959, when 
engines 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". Competitors sprang up and copied and 
improved his design. In the 1970s there were over a hundred of snowmobile 
manufacturers[5]. From 1970 to 1973 they sold close to two million machines, a 
sales summit never since equalled, with a peak of half a million in 1971[5]. 
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 rebounded to 260,000 in 1997 but went down gradually 
afterward, influenced by warmer winters and the use during all four seasons of 
small one- or two-person ATVs. The snowmobile market is now divided up between 
the four large North American makers (Ski Doo, Arctic Cat, Yamaha, and Polaris) 
and some specialized makers like the European Alpina Snowmobiles[5], [6]. 
Modern snowmobiles can achieve speeds in excess of 120 mph [190 km/h]). Racing 
snowmobiles reach speeds in excess of 180 mph [288 km/h].