On May 9th, 2016 the bison was named America’s National Mammal and stands as symbol of the greatest conservation success stories in the history of the country. Since the late 1800s the US Department of Interior has been integral in conservation stewardship supporting 17 bison herds in 12 states (approximately 10,000 bison).
Yellowstone National Park is the only place in the United States where bison have lived continuously since prehistoric times. Yellowstone’s bison population roam relatively freely over it’s expansive 2.2 million acres providing visitors unparalleled opportunities to observe North America’s largest land animal.
Visitors to Yellowstone are advised to maintain a minimum of 25 yards away from bison at all times but it some instances close encounters do occur and Yellowstone actually recommends the use of bear spray as a last resort as it can be effective at deterring an aggressive bison. The circumstances leading up to this bison encounter on a Yellowstone boardwalk are unclear but the man clearly felt threatened and deployed a quick blast of bear spray but the passing cloud seemingly had no effect on it.
The circumstances leading up to this encounter are unclear but the best way to discourage negative encounters with Yellowstone’s bison is remain alert to their presence at all times and give them proper space. Sharing the landscape with bison requires a heightened sense of awareness more than anything else. Simply put, bison pose no threat to people unless you get too close.
Yellowstone National Park Personal 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.