Early 1970s Motocross standout Mark Blackwell signs autographs during a race and at least one fan seems very excited about it. Mark won the 1971 American 500cc Motocross title (a predecessor of today’s AMA National Motocross Championship) by being the top-scoring American in the Trans-AMA Series. (Cycle News photo) #markblackwell #earlyamericanmx #happyfans #excitedfans #amamotocross #transama
Rider Files 