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.

Thomas Wilson (691) leading Randy Gaddey (80), Marty Miller (behind Gaddey) and Stevie Patterson (1) in a 1990 Michigan Grand Prix race at Grattan Raceway. (Larry Lawrence photo)