2005 Johnson contested the AMA 250cc Motocross Championship, best result a 15th-place overall finish at Millville, Minn... Raced with Maestro Suzuki team.
2004 Johnson raced a limited AMA 250cc Motocross season, best result 10th overall at Washougal, Wash... Raced with MDK Motorsports Kawasaki.
2002 Raced a limited AMA 125cc West Region Supercross series, best result seventh-place at the Jan. 19 Anaheim, Calif race... Raced a limited AMA 125cc Motocross season, best overall result sixth-place at Mt. Morris, Pa... Raced with Team Shark Honda.