meh! was at yellowstone 5-6 years ago, there were always bison in the road, sometimes running, sometimes, walking, sometimes just standing a blocking F#$^T$%%$$ traffic. They are as lazy as humans, taking the easiest route to get from point A to point B. One even came into the campground we were in, everyone was just watching it until the ranger came and told everyone they need to stand behind something in case of a charge, these things are dangerous. Now if you saw mountain goats, raccoons, rabbits, elk, and a few bears mixed into that herd, then I might be concerned.