I was heading to a state park on my map, and got off the highway to check my map, when a biker named Kenny showed up, told me about a campground just down the road, and led me to it. It's the Yogi Bear Jellystone campground, private, so it's got all the long-term campers, which some people dislike, but it means I have electricity and water on my campsite, a good internet signal, nice showers and probably even a restaurant and bar, among other things. No fear of bears and no mud to drop the bike here, either. I'm not sure why it wasn't on my map - maybe it only has public campgrounds - but I should look for ones like this in the future.
In the meantime I'm going to explore the grounds a little, then cook some dinner.