This is a really cool campground inside Craters of the Moon Park. We stayed one night, could have stayed one more. Hiking trails, visitor center museum, very good ranger talk program at night (try to go, there's a slide show, campfire, very entertaining, kids will like too-you'll be glad you went, only about 40 minutes). Water at the campground comes out of a hand pump faucet. Fun time.
We loved, loved, loved this campground. Stayed in August, while visiting Yellowstone. We had a site overlooking river. Had the back door of our RV open and could see/hear the river while we were in bed. Was super nice with the full moon coming up over the mountains & reflecting on the river. It was magical. Super quiet, clean everything, showers & laundry room especially nice, clean. Bathroom laundry closes every day at 11am but we were out visiting Yellowstone so didn't matter too much. There's a campfire get-together with pizza but we didn't make it to that. Nice people working there. It took us about 25 minutes to drive to Gardiner MT, entrance to Yellowstone. Will stay again.
We were disappointed with this place. it's 20 miles from West Yellowstone, but it took about 40 minutes to drive there. Any money you save staying here will be spent on the extra gas to drive there and back...if you have a gas hungry RV. It's out in the middle of nowhere, seriously, there is nothing out here. So be prepared. Not really convenient to visiting Yellowstone, we found it was better to pay more $ and stay at an RV park in West Yellowstone than at Red Rock RV park where the sites are crammed close together with no view.