This refuge was established separate from the Yellowstone heard to protect the bison. There are several groups spread over the park. There of course are other animals there along with the Bison.
In regards to the Bull I was inside my Jeep Grand Cherokee and parked on the edge of the gravel road. He looked at me but did not consider me a threat though my window was open but engine was turned off. So he stayed pretty relaxed as I took his pictures. As I was leaving I saw a lady get out of her car-husband was driving- and she started walking towards him- she was less than 20 feet away as I drove off thinking what a fool!