Yellowstone National Park’s bison herd was nearly extinct at the end of the 1800s with the population dwindling to about 23 individuals by 1902 due to over hunting and habitat loss. After extensive conservation efforts in the subsequent century, the bison population has grown substantially and now Yellowstone is home to over 5,000 bison. Notably, Yellowstone’s bison are the only continuously free-ranging bison population in the contiguous United States since prehistoric times.
Tourists come from far and wide for the unparalleled opportunity to observe the largest land-dwelling mammals in North America freely roam Yellowstone’s 2.2 million acres and sometimes it can be quite thrilling. Such was the case for this group of vehicles caught in what’s known as a “bison jam” on an autumn day inside the park.
Bison jams can be monotonous affairs with the large bovine slowly ambling through cars or even taking naps in the middle of the road, but if the bison happen to stampede its anything but boring. Thankfully its looks like all of the tourist wisely stayed in their cars and the bison passed through without any physical contact, maybe a few scuffed bumpers but that is the risk you run driving through one of America’s wildest places.
Bison stampede for a variety of reasons, mainly to avoid perceived threats. They are herd animals that instinctively rely on group dynamics for protection when they sense danger. Whether it be from predators or human generated disturbances, bison will run as a single mass at speeds up to 35mph, so being caught in the middle of a stampede is obviously extremely dangerous. For this reason and many more, Yellowstone requires visitors to maintain at least 25 yards away from bison at all times. Remember folks, bison may appear docile but they have injured more people in Yellowstone than any other animal.
Yellowstone Bison Safety Guidelines:
- Always stay at least 25 yards 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.