We stayed at what is now Cascadia County Park (per signage at the park) at the beginning of September. Monday and Tuesday night there were only a couple of other campers in the park. Needless to say it was very quiet. 

Our first day we noticed a man without a shirt sitting, leaning against the bathroom exterior wall for a least an hour or so. Later that day we saw a couple who appeared to be homeless using the shower on the premises. Neither of these people caused any problems nor interacted with any camper as far as I could tell. Near the entrance at the picnic area there is a sign warning visitors to lock their cars.

This is a beautiful park, densely forested, bordered by the Santiam River. We stayed in one of the pull though sites, number 4. It was more private than most sites. We were happy to stay here to escape the smoke in Central Oregon were we live. We had reservations at Little Crater Campground, but choose not to stay there as the there were fires nearby and the area had an Evacuation Advisory - Level one and there is only one way out of the area.