RV parks and KOA vary widely though and some can actually be quite nice.
so true. I can recall staying at 5 different KOAs. The one outside of Whitefish, MT was ok but needed a facelift. The St. Mary, MT one was also ok, but the ground squirrel burrows littered throughout the tent camping field posed a risk of ankle injury. Westhampton, MA was relatively small, and quiet in September, but seemed to have only one true tent site, which I had reserved ahead of time. The Missoula KOA is, despite its size, actually quite nice. They run a tight ship there and have security patrols because of its location. I have started 4 tours there and ended 2 there. The hot tubs (no children allowed) are a nice amenity. The one near Hill City, SD was a zoo. Really crowded. No shade at any of the tent sites. At night the hot tub/pool was filled with mostly drunks.
This place is probably the most tricked out private campground I even stayed at while touring alone. It's located on the Atlantic Coast route:
https://www.loneoakcampsites.com/The place is like a city in itself, complete with a bar. First time I stayed there was in '99. I paid close to $30, which was a lot back then. The cheapest site is now $53 with no hook-ups. I was there on a Saturday night in September. The place was jumping, in part because they were having an end of season party that included a dance for teenagers.
Stayed there again in the mid-2010s on a September Sunday. Much mellower as seasonal people headed home for the upcoming week. When I called before the trip to ask about the need for reservations the woman I spoke with told me there was a cyclist discount and that I wouldn't need a reservation. I think I paid $25 for the night.
Another crazy place was in ME, near the end of my Northern Tier group trip. The ride leader notes described the place as "Combat camping at its finest." I am pretty sure this is the place:
https://lakepemaquid.com/