I had a free day in my trip through North and South Dakota this month and I went to Medora and spent the day hiking the east side of the park. I made a full 28 mile day out of all the trails on the east side. It was a beautiful day and I saw almost all the parks wildlife. I had the trails to myself.
Bison
Elk
Coyotes in with the Prairie Dogs
Wild Horses
Deer
I finished back where I started, just as evening light was fading.