Yellowstone National Park offers 2.2 million acres of unbelievable natural wonders, presenting visitors with the opportunity to visit geothermal areas that contain around half the world’s active geysers, view geologic wonders like the Grand Canyon of the Yellowstone River, and experience charismatic mega-fauna like the moose, elk, bears and thriving population of wolves.
The current Yellowstone wolf population exists thanks to a reintroduction effort that ran from 1995 to 1997, with 41 wild wolves from Canada and northwest Montana released into the park. As of 2024, that population has grown to at least 108 wolves. While elk is their primary prey, Yellowstone’s bison are also very much in their diet.
Yellowstone is the only area in the U.S. where bison have lived continuously since prehistoric times. They make up the largest bison population on public land in the country, with thousands of individuals roaming relatively freely over park land and some surrounding areas. Dead bison provide an important source of food for scavengers, but the adult bison only faces threats from grizzly bears and wolves.
The following footage captures a wolf pack’s attempt at taking down a bison. Unfortunately for the wolves, the bison manage to work together as a group to force their attackers away.
Yellowstone’s bison are significantly more harmful to humans than Yellowstone’s wolves, injuring more people in the park than any other animal. However both need to be given respect and plenty of space. Wolves and bears need at least 100 yards of space at all times, while all other animals should be given at least 25 yards. Read more on wolf and bison safety below.
Yellowstone National Park Wildlife Safety:
Bison
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.
Wolves
Wolves are not normally a danger to people, unless they become habituated to their presence and food (there has never been an attack in Yellowstone). Two habituated wolves have been killed in the park. Help us protect wolves in Yellowstone by:
- Remaining at least 100 yards away when watching or photographing them.
- Telling a ranger if you see wolves near developed areas or approaching people.
- Keeping your dog leashed at all times when it’s outside a vehicle.
If you’re concerned about a wolf because it’s too close or not showing any fear of people, stand tall and hold your ground. If the wolf approaches you, wave your arms, yell, and flare your jacket. If that doesn’t discourage it, throw something at it or use bear spray. Group up with other people, continue waving and yelling, and tell a ranger as soon as possible.
Do not handle wolf scat: it may contain tapeworm eggs that can cause hydatid disease in humans.