There seem to have been two paths to development of the modern snowmobile. One started when Carl Eliason of Sayner Wisconsin built what is basically a motorized toboggan in 1924, which was patented in 1927. The other path started when Joseph Armand Bomdardier of Valcourt Quebec built a snow coach in the 1930s.
From the first motorized tobogan, Eliason began to make his machine larger and less like a toboggan and more like a modern snowmobile. The Eliason's motorized toboggan started out with a 2.5 hp motor, and by 1937 used a 25 hp motor.
Meanwhile, in Quebec Bombardier built a propeller driven snow buggy in 1922. Not entirely successful, his father made him take the propeller off so it would not decapitate any of his siblings.
More development led to a 1927 snow vehicle which resembled a Model T on skiis.
His next effort led to the successful B-7 model in 1937, which was more of a car on tracks and skis. This was the first model that Bombardier patented. Bombardier then made a number of tracked snow vehicles, include a school bus version, and other larger industrial vehicles.
In 1953 the Eliason machine was the K-12, which was the last production model. Eliason went out of business in 1963, but a number of other companies, like Polaris, made machines based on the expired Eliason patents.
It wasn't until 1959 that Bombardier marketed the Ski-doo.
Bombardier became a huge company, with activities in aerospace and transportation, with subsidiaries like Challenger and Global. Bombardier bought the Lear Company, of Lear Jet fame, and also Rotax, makers of engines. In general, in anything to do with transportation, a Bombardier subsidiary is involved.