Next photos are from the official program from the 1972 Trans-AMA race at Honda Hills.
Notable things about the 250 support race were that I think it was the first appearance of the Penton 250 given a strong ride by Jack Penton. Bill Wetzel of Wetzel's Suzuki was entered along with Gary Semics and George Singlers son Mike. Overall Ohio was given very strong rider representation because all of the Ohio guy who were entered were fast.
The 1972 Trans-AMA motocross series was the third annual international series established by the American Motorcyclist Association as a pilot event to help establish motocross in the United States. The motocross series was an invitational based on a 500cc engine displacement formula, run on American tracks featuring the top riders from the F.I.M. world championship against the top American riders.
Swedish Maico factory rider Åke Jonsson dominated the championship, winning nine consecutive overall wins. 500cc world champion, Roger De Coster and Heikki Mikkola placed second and third overall, claiming one victory apiece to start off the series before Jonsson began his winning streak. Brad Lackey was the highest-placing American rider, finishing the series sixth overall.
The rider named Bryan Kenney who finished 6th. at the Linnville round that mjshafer62 posted earlier was I believe from Cleveland Ohio if the old memory is still serving me.
Kenney also was one of if not the first American to go to Europe. He ran quite well in a few international races
This was one of the first American's I remember riding in the GP's. I would follow the GP's in Cycle New's with the reporting by David Maltais. Scroll down the page at Ed Youngblood's "Motohistory" to see the related photos. Great read.