Traffic-related accidents are the most common cause of injury and death in the park. Don’t let the scenery distract you: drive cautiously and watch for animals. If you need to stop for any reason, use a pullout: do not block traffic. The speed limit in Yellowstone is 45 mph (73 kph) unless posted otherwise. Pack your patience: winding roads and traffic often make drive times much longer than expected. Other road hazards include soft shoulders, potholes, and frost heaves. If you have detachable side mirrors, please remove them when you're not pulling a trailer. For details on road closures and construction, check out our park roads page.
Most of the park lies more than a mile above sea level, so give yourself time to adjust to the elevation before engaging in any strenuous activity.
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.
Cow elk are especially fierce and protective around their calves in the spring. Around Mammoth Hot Springs, they often hide calves near cars or buildings. Be cautious when exiting buildings or approaching blind corners. You can sometimes stop a charging elk by making yourself look bigger, yelling loudly, and aggressively waving your arms or a jacket. In the fall, bull elk battle for access to cows and challenge other males during the rut. They also charge cars and people who get too close. Always stay at least 25 yards (23 m) away from elk.
Boardwalks and trails protect you and delicate thermal formations. Water in hot springs can cause severe or fatal burns, and scalding water underlies most of the thin, breakable crust around hot springs.
- Always walk on boardwalks and designated trails. Keep children close and do not let them run on boardwalks.
- Do not touch thermal features.
- Swimming or soaking in hot springs is prohibited. More than 20 people have died from burns suffered after they entered or fell into Yellowstone’s hot springs.
- Pets are prohibited in thermal areas.
- Do not throw objects into hot springs or other hydrothermal features.
- Toxic gases may accumulate to dangerous levels in some hydrothermal areas. If you begin to feel sick while exploring one of our geyser basins, leave the area immediately.
More than 100 people have died in Yellowstone’s lakes and rivers. Cold water makes hypothermia a year-round risk, and spring snow melt makes rivers dangerous to cross. Read more hypothermia and stream crossings on our backcountry safety page.
Animals & Human Food
Never feed wildlife, even birds and squirrels. Animals that become dependent on human food may become aggressive toward people and have to be killed. Animals also carry diseases that can be transmitted to people. Be especially watchful around ravens: they can unzip or unfasten many different kinds of buckles and latches.
- All of Yellowstone is bear habitat, even the boardwalks around Old Faithful (and other thermal areas).
- Never pursue a bear to take its picture. When viewing bears along roads, use pullouts and stay in or near your car.
- Keep all food, garbage, and other scented items stored in bear-proof containers when not in use.
- If a bear approaches or touches your car, honk your horn and drive away to discourage this behavior.
- Follow the best practices for hiking in bear country: be alert, make noise, hike in groups, do not run, carry bear spray and know how to use it.
- If you see someone hurt by a bear, witness aggressive bear behavior, or see a bear obtain or try to obtain human food or garbage, call 911 immediately or notify any park ranger.
Wildfires have left thousands of standing dead trees that can fall with little or no warning. In 2015, a falling tree killed someone on a hill near the Midway Geyser Basin. Avoid areas with large numbers of dead trees, and watch for dead trees along trails and roads, or in campsites and picnic areas.
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.
Winter brings its own set of challenges, including sub-zero temperatures, icy roads, and blinding snow storms. Read more about staying safe while enjoying Yellowstone's quiet season.