Yellowstone National Park‘s unique wildlife is highlighted by the bison, North America’s largest land mammal. The 2024 population estimate for bison inside the park was 5,400, representing the largest population on public land in the United States. As the only place in the nation where bison have lived continuously since prehistoric times, the animals continue to exhibit wild behavior like their ancient ancestors including congregation during the breeding season to compete for mates and migration and exploration resulting in the use of new habitats.
Bison are massive animals, with males weighing up to 2,000 pounds and females up to 1,000 pounds. In the summer bison herds typically average around 200 animals, meaning a single herd could easily weigh between 10-20 tons. With that kind of weight it’s no surprise that a Yellowstone herd can cause a bridge to sway and shake as they stampede across it, as shown in the video below. The movement of the sideview mirror is due to the bridge shaking, not by unsteady hands.
While they may seem fairly harmless, bison are responsible for more injuries inside Yellowstone National Park than any other animal. Visitors should never approach the beasts and should follow Yellowstone’s guidelines requiring 25 yards of space between people and bison. Stay with your car if you encounter a traffic jam caused by bison and remember that the safest place to view Yellowstone’s remarkable wildlife is from inside your vehicle. Read more on bison safety below.
Yellowstone National Park Bison Safety Guidelines:
Bison have injured more people in Yellowstone than any other animal. Bison are unpredictable and can run three times faster than humans. Always stay at least 25 yards (23 m) away from bison.
- Give bison space when they are near a campsite, trail, boardwalk, parking lot, or in a developed area. If need be, turn around and go the other way to avoid interacting with a wild animal in close proximity.
- Approaching bison threatens them, and they may respond by bluff charging, head bobbing, pawing, bellowing, or snorting. These are warning signs that you are too close and that a charge is imminent.
- Do not stand your ground. Immediately walk or run away from the animal. Spray bear spray as you are moving away if the animal follows you.
