Ah yes, the Blackfeet Nation. I worked the ER there for a few years. We usually had our first motorcycle wreck in May. Then a pretty steady stream through the summer. When traveling from St Mary to Browning on 89 there was a blind off camber decreasing radius turn, it got a lot of people on bikes and cars.
As far as hitting a horse or cow there, I can guarantee that if you hit one and kill it they will turn out to be a prize winning bull or roping horse worth more than your car. It seems every animal that got hit was very special, not special enough to keep confined just special when it gets hit.
bob