The first Big Bear Motorcycle Run was held in 1921. It's rumored that it started out as a bet between a couple of guys at a bar in Los Angeles on New Year's night. The bet was to see who could make the 100 mile ride to Big Bear Lake first. There was no set route, so one took the back way through the desert and the other tried the more direct route by road. Since it was early January, the roads were blocked by snow and the second rider was unable to complete the race. As time went on, more and more riders started participating, but after the first year, the race always ran through the desert. Eventually, it became a full blown race with entry fees and trophies for the winners, reaching it's height in the 1950's.
By 1960, nearly one thousand riders showed up for the race. The amount of traffic this event generated caused the California Highway Patrol to shut down the race for the following year, making 1960 the last year of the Big Bear Motorcycle Run. Conditions for the last race were extremely dusty as you can see from the pictures. The winner of the final race was Eddie Mulder astride a 500 Royal Enfield.
Photo credit goes to Ralph Crane, although you'll find that his photo's are incorrectly dated as 1961.