Great, but small...
Horning's Hideout is a great small campground, just 45 min from Portland. They have fishing, disc golf, concerts. You can camp there on the weekends or just go there for the day!!
Great campground!!
Champoeg is a great family friendly campground. It is a great place to camp, if you need something close by. There is also access to a boat dock with a 72 hour docking limit. (but there is no boat launch).