Has there ever been a pro AMA motocross or supercross racer that started riding at 10 an racing at 15?

yes. i know dean ferris isnt in the ama but hes one of australia's top riders and he didnt race until he was about 14. i got my first bike when i was 9 and started racing when i was 14. im now in my second season and im mid pack at state events. im not going to make the ama but will atleast still get some speed up and enjoy my racing