No, I don't. I've talked to two guys over the past two days who are about my age and who drove in the event. They both say it was actually in Empire, but one says it was called the Traverse City Hillclimb for a few years because it was a Traverse City club that sponsored the event.
Anyway, as one described it, it came back to me. The top of the hill ended at a military radar station. He described the road as the "old south hill road". He's a commercial photographer and says he has some photos of the event that he shot in '74.
It's vague in my mind because I followed someone else there, and probably because I was exhausted from having spent the previous day and night trying to get the carburetor jetting right for my new Racer Brown 3/4 cam. (I never got it right until a couple of weeks later. It was very frustrating.)
From what they told me, it continued into the '80s, at which point the cars got too fast and the road got too torn up. One guy in a Formula Atlantic spun and hit a tree going backwards, and almost died. That was the last race.
I can hardly imagine driving an FA on a public road. It's got to be ridiculously dangerous.