Some private campgrounds usually have rules about tents though I never had a problem at KOA. Most public campgrounds intermix motorhomes, trailers and tents in the same area. I prefer public campgrounds and putting up a tent and leaving in a car is usually acceptable as many people are off visiting trail heads or taking part in activities. National Forest campgrounds usually don't have a post to indicate occupancy and are self-pay, and leaving behind a tent is the only really visible and for sure method to indicate occupancy even for scavenger thieves.