The Grass Eater That Tosses Tourists
Bison have injured more people in Yellowstone than any other animal — more than bears or wolves. A 2,000 pound bull runs at 35 mph, three times faster than a human, and it only eats grass.
Why Yellowstone’s Most Dangerous Animal Eats Grass
Ask most visitors which Yellowstone animal to fear and they will say bears or wolves. The park’s own records say otherwise. According to the National Park Service, bison have injured more people in Yellowstone than any other animal.
Two Thousand Pounds at 35 Miles Per Hour
A bull bison can weigh up to 2,000 pounds. Despite that bulk, it can run at around 35 miles per hour — as the NPS puts it, three times faster than a human. Bison also turn far more quickly than their size suggests, which is why people who think they can outrun or sidestep one are so often wrong.
The Injury Record
Research from Utah State University documented 56 people injured and two killed by bison in Yellowstone between 1978 and 1992, and injuries have continued every year since as visitor numbers have grown. The park announces new goring incidents most summers, and the pattern is almost always the same: someone approached too closely for a photo.
The Twenty Five Yard Rule
Bison are grazers, not hunters. They charge to defend their space when they feel threatened, not to attack for food. That is why the park’s rule is simple and specific: stay more than 25 yards (23 metres) away from bison, elk and other large animals, and at least 100 yards from bears and wolves. Inside that distance, a bison can decide you are a threat, and a horn under the ribs is how it responds.
A Warning That Still Gets Ignored
The gap between how bison look — slow, calm, grazing — and what they can do is exactly what makes them dangerous. A one ton grass eater that can hit 35 mph does not need teeth or claws. It only needs you to stand a little too close.
