I normally drive 250-300 miles a day on long trips. I had just finished my 300 miles, crossed into Missouri on I-29, and there are NO RV Parks that I could see. So, I just randomly took an exit, hoping to find SOMETHING, ANYTHING! I wound up in Craig, MO. I weasled around, and LO AND BEHOLD, a sign! RV Park two blocks away! I drove to it. Oh my. Seven spaces, on grass, near an alley one block from the main street. Only one dilapidated trailer (presumably the owner) on site. I asked some locals if I would be safe, I was assured I was safe. Called the after hours phone number only to get voice mail. Finally located the owner at a community fish fry that was being held that evening.
Price was cheap, but I had to put up with trains and barking dogs from neighboring homes. But for one night... heck, and I even went to the fish fry!
I eventually discovered that if I had kept going, there was a state park down the road. But I'm betting this place was cheaper.