In the late 1980s WERA started a one-track championship called the Michigan Grand Prix (actually I think they spelled in the Americanized Gran Prix early on). The Michigan Grand Prix was a series at Grattan Raceway that paid most of the field’s entry fee back to the top finishers. If I remember correctly the race was open to any motorcycle so you’d see everything from 250cc GP bikes, to 1100cc Superbikes. This photo is a Michigan Grand Prix race from 1990. It shows an up-and-coming Thomas Wilson (691) leading Randy Gaddey (80), Marty Miller (behind Gaddey) and Stevie Patterson (1). Wilson won the race, while Gaddey went on to win the championship.