When I worked there in the early 1980's we had concerts almost weekly from touring acts. Some of the more popular ones could have people parking in the grass near the exit. Cheap Trick drew quite a crowd.
The other big day was the "Senior Night" that kept the park open until some insane hour (3:00am?). Due to some boneheaded scheduling a lot of us had to open the next morning. Quite a few people slept in their cars.