Been about a decade since visiting Yellowstone, but we did as you are suggesting. It's exactly what I will do next time. There was a very nice private park within walking distance of the Grizzly & Wolf Discovery Center. That center was worth the trip to this Biology major. Also, just west of town was a great public facility that was virtually vacant in August. Almost 3 decades back we were at Custer in a customized van. We loved it. Hard to believe we haven't been back. Might I also suggest you consider Lassen National Park NE of Redding, Ca. A relatively easy trail, Bumpass Hell, takes you to a mini Yellowstone. Very nice camping in the park. Great private parks in Redding. Crater Lake in Oregon is a must see also. Your in for a great trip!
