Brown bear roaring in forest
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The Most Dangerous Animals You Might Encounter at a National Park

Many people visit national parks to see wildlife in its truest form, and it's an exhilarating experience. That same exhilaration can also bring fear of all the possibilities of what could happen while encountering some of the most dangerous animals in the nation. These types of deadly animals range from apex predators, to hoofed mammals, to some of the smallest but most deadly creatures the world has even known (we're looking at you, ticks). And if you don't know what to do if you come face-to-face with one, it could get ugly really quickly. So here's a list of the most dangerous animals you could encounter at a national park and what to do if run into one of them.

The Big Guys


Grizzly bear in the autumn forest

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Bears might be cute from the other side of a zoo enclosure, but they can also be ferocious and vicious creatures if encountered in the wild. As apex predators, these animals should be observed from a distance and always avoided if possible. They normally eat a wide variety of foods, ranging from nuts and berries to elk and trout. But they can be pretty unpredictable when it comes to their interactions with humans, so it's best to stay as far away as possible if you run into one. While bear attacks in national parks are few and far between, they aren't nonexistent. According to the National Park Service, bear injuries in Yellowstone National Park average about one every 20 years and total fatalities are less than deaths caused by drowning, burns, and suicide. "To put it in perspective," the NPS explains, "the probability of being killed by a bear in the park (8 incidents) is only slightly higher than the probability of being killed by a falling tree (7 incidents), in an avalanche (6 incidents), or being struck and killed by lightning (5 incidents)."

It's extremely important to always be prepared in case you encounter one. Before you start your adventure, check in with the park's visitor center for any updates on bear safety. Make sure you have a can of bear spray with you and know how to deploy it. And should you come face-to-face with one, stay calm especially if you're around a mother and her cubs.

Two types of bears to be weary of in national parks are grizzly and black bears. Grizzly bears are a subspecies of brown bears and can be primarily found in northern states like Wyoming, Montana, Idaho, Washington, and Alaska in parks such as Yellowstone, Grand Teton, Glacier, Katmai, and Denali. Black bears can be found all across the mainland U.S., with higher concentrations in the southwest and southeast in parks such as Shenandoah and Great Smoky Mountains.


Grey wolf standing in snow-covered landscape

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The reputation of wolves has gone back and forth between being admired and feared, and from being considered a pest to federally protected by an endangered listing. Although the species has historically been misunderstood, they shouldn't be taken lightly as they're still wild animals. As key players in conserving the environment and regulating ecosystems, their diet varies between small and large prey. What makes them dangerous is that they can kill animals that other predators can't usually kill such as elk, deer, and bison. And while coyotes can wait nearby to clean up the scraps, bears are some of the only other animals that can scare wolves away from their meals. But protecting livestock is ultimately what caused humans to hunt wolves almost to extinction, according to the NPS.

Wolves are primarily found in northern states such as Wyoming, Idaho, Montana, Michigan, Minnesota, and Alaska in parks such as Yellowstone, Grand Teton, Isle Royale, Voyageurs, Katmai, and Denali. But while wolves can be dangerous in their nature, there are rare cases of attacks of humans, the number considered far too low to even calculate. However, just like most predators, wolves can become dangerous to people if they become habituated towards human-related food including poorly-handled camp food, garbage, and livestock. So if you're visiting popular wolf havens like Yellowstone, make sure you know what to do in case you encounter a wolf. It's similar to what you should do if you encounter a bear, except the difference is that you'll want to yell or throw stuff at the animal if it approaches you. Worse case scenario, you can always deploy your can of bear spray. And if you bring your furry best friend with you to go hiking or camping, make sure to keep it leashed.

Dangerous Ungulates


American buffalo or bison grazing on the plains in Grand Teton national park with the mountain range behind

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Dangerous wildlife in national parks doesn't only consist of strong, carnivorous predators with sharp teeth and claws. Ungulates such as bison, elk, and moose can be pretty menacing too. In fact, bison, America's largest land mammal, have been recorded attacking victims three times already this year in Yellowstone. Although they were completely provoked, these majestic creatures are not easy to defeat. Bears and wolves, as we mentioned above, are really the only predators of these hoofed royalties. According to the NPS they were once endangered, and their populations have been recovering from less than 1,000 to 19 herds that roam across 12 states that make up the Great Plains. Parks such as Badlands, Grand Canyon, Grand Teton, Theodore Roosevelt, Wind Cave, Wrangell- St. Elias, and Yellowstone have been partnering with Indigenous Tribes and Canadian First Nationals to actively advance conservation efforts.

Bison are big herbivores, but are surprisingly agile and fast. They can run up to 40 miles per hour and are incredibly protective of their families. But avoiding bison attacks isn't hard. The NPS recommends that visitors stay at least 25 yards away from the creatures. The Yellowstone attacks were caused by tourists failing to observe the bison responsibly, so trust us- the selfie isn't worth it. Don't hike through bison herds, especially if it's between a cow and a calf. If one stops and looks at you, that's a pretty big sign that you're probably too close. Slowly back away, and don't make any sudden movements to startle it more than your presence already has. Remember, the point is to prevent bison attacks because once one's charging at you, there's not much you can do about it.


A strong mature bull elk in Rocky Mountain National Park

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Many people visit national parks to see all the great wildlife roaming freely across the land, and ungulates can be safely observed if it's from a safe distance. Visitors often head to Yellowstone, Rocky Mountain, Grand Canyon, and Great Smoky Mountains National Parks to see these incredible animals, and sometimes cause traffic jams because a passing herd draws so many drivers' attention on the park roads. Most ungulates are primarily herbivores, but known to be aggressive when they become defensive. Elk are larger than bears and can be dangerous despite being deer. And while they rarely attack humans, there is a consistent history of elk-related injuries. Were they provoked? Actually, not all the time like most bison. So it's important to know when you should be extremely weary of elks and what to do if one charges at you.

While you wouldn't be in a bad situation if you see one, it's important to keep your distance especially during two specific times of the year. Cow elk are extremely protective of their young, so you'll want to avoid being in their line of sight during calving season which is late spring and early summer. And in September and October, it's mating season. Bull elk are very aggressive during this season, with their testosterone levels rising as they spar with each other for mating rights of multiple cow elks.

While keeping a 25-yard distance from an ungulate is the standard, an extra five yards on top of that is recommended for elk. The signs to tell if an elk is agitated include its grinding teeth, ears laying backwards, lips curling, hair raising, or it stops and starts circling around. If you notice these signs or realize you're too close to an elk, start slowly backing away while making sure you don't startle it. Unlike bison, if an elk starts charging at you, you can definitely run and find cover. According to the NPS, it's very unlikely that they'll follow you. If they do, it won't be for very far. And if you do get knocked down by one, curl up into the fetal position and protect your head with you arms while keeping still. Fighting back will only convince it that you're a threat.


Moose walking through Brainard Lake in Colorado

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And if you thought elk were big, moose are actually the largest members of the deer family. They're nearly a foot taller than elk and can weigh up to 1,500 pounds. They're distinguishable by their large antlers and can be found in northern states such as Michigan, Wyoming, Montana, Idaho, and Alaska. Some of the best national parks to see these massive creatures include Isle Royale, Yellowstone, Grand Teton, Glacier, Rocky Mountain, Denali, and Voyageurs. And by law, visitors must stay at least 25 yards away. But people are actually more likely to get injured by moose than bears. If you're perceived as a threat when encountering one, these animals won't hesitate to charge at you especially if a cow moose is with its calf.

If you see one while adventuring around a national park, you really don't want to be noticed. If you are, you'll have to convince it that you're not a threat. That means talking in soft voices and slowly moving out of the area to create distance between you and the animal. Take extra precaution if you notice signs that the moose is agitated such as if its ears are laidback and has upright hackles. Those signs mean that it's getting ready to charge at you. Thankfully, you can run away from moose the same way you can run away from elk if one starts charing at you.

The Sneaky, Small Critters

Black Widow Spiders

Black Widow Spider on Log

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Some of the most dangerous animals in national parks aren't the biggest ones. It's scary to think how even the smallest creatures can do some life-threatening damage. Black widow spiders are the most venomous spiders in North America, about 15 times stronger than rattlesnake venom according to the Smithsonian. They're found in the southern and western U.S. in parks such as Arches, Grand Canyon, Zion, White Sands, and Canyonlands National Parks. They're identifiable by their black, globe-shaped abdomens with a red or orange hourglass right in the middle. They primarily eat insects and other small creatures, but about 2,500 people report getting bitten by them every year. Less than 10 people die every year from these spider bites, but it's mostly because they probably have compromised immune systems or a severe allergic reaction to the venom. However, black wido bites are extremely painful and cause serious symptoms if not treated medically. According to the NPS, symptoms can vary and aren't limited to stabbing pain, swelling, two red spots from where the spider punctured the skin with its fangs, abdomen and back pain, nausea, profuse sweating, difficulty breathing, tremors, fever, and increased blood pressure.

Like most animals, these spiders are not aggressive unless they're startled or defensive. Yes, female black widows are known to eat their mates which is pretty daunting to wrap your mind around. Females think it's practical to eat their mates if they're hungry because they're bigger than male spiders. But that means a black widow is probably not trying to eat you since humans are much bigger than them. However, you should definitely be careful while hiking or camping through a national park. The NPS recommends that you avoid sticking your hands in places that you can't see like in leaves or under rocks. If you're gathering firewood, wear gloves to do so or while you're moving rocks or debris. And make sure to always shake out your clothing and shoes when changing. If you do get bitten, seek medical attention immediately.


Tick Reaching For Human Leg Passing By in Forest.

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Ticks are some of the most dangerous animals in national parks because they can cause diseases in humans and animals, but are very difficult to see with the naked eye. There are more than 850 types of ticks known in the world, and these creatures are bloodsucking parasites that live externally on other living beings. They require hosts to live and reproduce, but interesting only require three blood meals to complete their life cycles. They're found all across the U.S. in mostly busy, wooded, and grassy areas so you might find them in national park such as Rocky Mountain, Acadia, Cuyahoga Valley, Shenandoah, and Sequoia and Kings Canyon National Parks. Infected ticks transmit diseases such as Lyme disease, which causes a rash (often in a bullseye pattern), flu-like symptoms, joint pain, fever, and weakness. Most people can recover completely with the appropriate antibiotic treatment, but in some cases can develop Post-Treatment Lyme Disease Syndrome which can last years.

Prevention is the best way to protect yourself from ticks while exploring a national park. Hikers should always stay in the center of trails and avoid high grassy areas. Wear insect repellant containing DEET or is EPA approved and make sure to spray it over your hiking boots too. You can also treat your clothing and gear with permethrin. Carefully inspect your body, clothing, and pets for ticks at the end of the day and the next morning, and tumble dry your clothes on high heat for an hour. They can be found in places that are hard to see such as the underarm, scalp, and groin areas. If you do find a tick, use fine-tipped tweezes to grasp it as close to your skin as you can. Pull it upwards evenly, carefully not twisting or jerking it. Once it's removed, you can dispose of it by putting it in alcohol, placing it in a sealed container, or flushing it down the toilet. Clean the bite area and your hands with rubbing alcohol or soap and water.

More Tips

We can't emphasize enough how important it is to know what to do when you encounter wildlife in a national park. For the bigger animals, you generally want to express that you are not prey by making yourself as big as possible but without startling it. Most animals won't be aggressive towards you if you can convince it that you're not a threat.

A good way to gauge if you're too close to an animal is using the Thumb Rule, which has three steps: 1. Make a thumbs up gesture towards the animal in front of you. 2. Place your thumb of the the animal in your point of view. 3. If you can still see parts of the animal around your thumb, then you're too close. Slowly back away to give the creature some space.

If you're unsure what to do, think calmly about the situation. If you see an animal with its babies, you probably want to stay away since most will become protectively aggressive. You should never run away from an animal unless it's a moose or elk because that could startle it even more. And never leave any human food or garbage around. Make sure you know how to dispose of waste properly so that an animal doesn't become habituated towards humans. Even if the habituated animal doesn't harm you, it could harm the next human that crosses its path.

READ MORE: 9 Best National Parks for Outdoor Enthusiasts