Dejan Corovic
As above, so bellow
Isn't this sighting from 1997 in Baraboo pretty close to the park?
UFO Sighting 1997 in Baraboo, Wisconsin
Sauk County Wisconsin, UFO Reports
I was actually going to suggest that there was another similar UFO encounter.
One hunter separated from his group of hunters, and when he was quite lone cylindrical UFO came and tried to make him sleep with some vapours. He escaped by climbing a tree and spending a whole night on that tree. But location was very similar to your friend's. Somewhere in California.