1970 Trans-AMA motocross series

The 1970 Trans-AMA motocross series was an international series established by the American Motorcyclist Association as a pilot event to help establish motocross in the United States.[1][2] The motocross series was an invitational based on a combined 250 and 500cc engine displacement formula, run on American tracks featuring the top riders from the F.I.M. world championship against the top American riders.

BSA factory rider Dave Nicoll claimed the championship without winning a single event, due to his consistent results. The Suzuki team of Joel Robert and Olle Petterson didn't join the event until the third race of the series. Robert went on to dominate, but his late start hurt his chances to claim the overall championship. As a result of his being the highest placed American rider at fourth overall, Dick Burleson, was crowned the first-ever American motocross national champion.