In 1965 Larson Boat Works, Inc had purchased a major interest in Polaris Industries, the maker of Polaris snowmobiles. In 1966, Larson decided to sell their interests in Polaris and try their luck at making their own line of snowmobiles.   In September 1966, Larson snowmobiles were being assembled by Paul Larson's Crestline Products in Little Falls MN.  The venture was a failure, as they just could not compete with existing builders. To the best of my knowledge, 1969 appears to be the last year Larson snowmobiles were produced.