Why do I think so? I didn't start working on the final geometry of the track until about 8 years later than that I think. 1978 for the opening perhaps?
The track was created by a half dozen local investors and "laid out" by a golf architect.
Making it work as a real racetrack was a tough but fun challenge for me at the time.
I'll just have to look in my old worksheet boxes.
Needless to say I have always had a soft spot for that place.
Up until 4 years ago I lived in the closest town to the track, Novato, which is just over the county line in Marin County.
Seriously, that's a fine track.