Nice spot, super crowded over Memorial Day weekend
This campsite is 6.9 miles up the trail to Enchanted Valley, which has to be one of the most visually stunning places on earth.
According to the campsite map, there's only 4 spots here. But on the Saturday before Memorial Day, there had to be at least 10 groups camped here (even some morons who pitched their tent directly below the bear wire). Even with the crowd, the place was free of trash (and bears) and was quiet.
Pros: Most of the spots are right next to the river, so you can fall asleep to the sound of whitewater. Lots of flat spots. A few trees for hammocks. A privy. Bear wire. Easy river access for getting water. Clean.
Cons: None really, although I'll probably camp at one of the well-established dispersed sites within a few miles of O'Neill next time. There are some awesome-looking spots with relative privacy.