Stayed here for a 2 night stay. Check-in was easy and the staff was nice. We chose Cherry Hill as a stop on our way to Yellowstone because of the activities for our daughter, but was a bit disappointed to find out that they were completely separate.
The campsite was rather nice. Lots of grass! They have spots that actually park on grass, or other sites that are asphalt with grass between. There are a bunch of Pull Through Full Hookup sites and our 38' Fifth Wheel fit no problem. Was able to disconnect the truck and still had space.
As for the amusement park, their prices seem a little high for what they offer. And you would think that there would be some kind of admission discount for staying at the campground, but there wasn't. The place seemed popular with some locals and was fairly well filled with people both days. Our second day, we opted to skip the water park because there wasn't a lot for our 3 year old to do. There are no age or height restrictions on the tub ride, but I wouldn't recommend it for a kid that can't fully sit across a tube.