We recently stayed at Medora Campground.  It was too early in the season to catch the Musical however we rode our bikes into town,  the local bike shop was great, and was able to fix my husband's bike!  The Campground itself is on the small side as far as sites go but they are pull-through which was convenient for our 2-night stay.  We were on a long trip and were happy to see laundry available on site, everything was in working order.   The bathroom was clean and the people we nice.   The location is right next to the entry into Theodore Roosevelt National Park and the visitor center.   If you like Mountain Biking  - Check out the Maah Daah Hey trail the is just outside the town of Medora.  I would recommend having someone drop you off at the trailhead.