Bison are HUGE. When we drove through Custer State Park, there was a big herd of them, and there was always some joker standing way.too.close and taking selfies. Talk about stupid. My farmer 'herds' his bison from pasture to pasture, and he's pretty darn careful about it. As he says, bison have only two speeds....grazing speed (slow walk while they graze), and stampede (faster than any human can run). There is no middle ground. And, they go from one to the other very quickly. Plus, they can turn very quickly and at high speed. Interesting to watch. We watched him "herd" them across a rural road to the other pasture, and he put up 'chutes' and managed to convince the lead bull to go through. The rest, literally, stampeded right behind. Took only a couple of seconds. You could feel the road vibrate something fierce as they ran across. (We were well back for safety). It must have been a magnificent sight when they roamed the prairies by the million.