Two weeks ago I spent two nights in my camper, right by the no camping sign on the put in beach. It was midweek, and I didn't see a ranger, so I can't say it's allowed or not. Just that I got away with it. On all my trips to the shitter, I noticed multiple cars camped in the upper lot. I have also camped in the upper lot, and spoken with the ranger that morning, who didn't mention the fact that we were camping. Forgiveness rather than permission I always say.
Dude, I'd see you on the river but I'm hardly ever out there.