Wyoming’s vast wilderness stretches across 97,914 square miles of dramatic landscapes, from the geysers of Yellowstone to the peaks of the Grand Tetons. This rugged terrain harbors some of North America’s most formidable wildlife.
Whether you’re hiking backcountry trails, camping in national forests, or simply exploring Wyoming’s natural wonders, understanding which animals pose real risks can mean the difference between a memorable adventure and a dangerous encounter.
You’ll find grizzly bears in the northwest mountains, rattlesnakes basking on rocky outcrops across the state, and bison herds that can turn aggressive without warning. This guide covers 15 dangerous animals you’re likely to encounter in Wyoming, where they live, and how to stay safe in their territory.
1. Grizzly Bear
The grizzly bear (Ursus arctos horribilis) stands as Wyoming’s apex predator and most potentially dangerous mammal. These massive carnivores can weigh up to 700 pounds and reach speeds of 35 miles per hour despite their size. You’ll find grizzly bears primarily in the Greater Yellowstone Ecosystem, which includes Yellowstone National Park, Grand Teton National Park, and surrounding wilderness areas in northwestern Wyoming. The region hosts approximately 700 grizzly bears, making it one of the largest concentrations in the lower 48 states.
Grizzly bears are most active during dawn and dusk hours, though you might encounter them at any time while they forage for food. Their diet consists mainly of roots, berries, insects, and carrion, but they’re opportunistic feeders that will consume anything from elk calves to human food if accessible. The greatest danger occurs when you surprise a bear on a trail, when a mother perceives you as a threat to her cubs, or when bears have become food-conditioned near campgrounds.
Pro Tip: Make noise while hiking in grizzly country by talking loudly, clapping, or wearing bear bells. This simple practice prevents most surprise encounters by alerting bears to your presence from a distance.
According to the Wyoming Advocates wildlife safety guide, carrying EPA-approved bear spray and knowing how to use it properly provides your best defense during a grizzly encounter. Always store food in bear-proof containers or hang it at least 12 feet high and 6 feet from tree trunks when camping in grizzly habitat. Similar safety protocols apply when exploring other Yellowstone wildlife encounters throughout the park system.
2. American Black Bear
The American black bear (Ursus americanus) inhabits forested regions throughout Wyoming, including mountain ranges, national forests, and even areas near human settlements. While generally less aggressive than grizzly bears, black bears still pose significant risks, particularly when protecting cubs or competing for food sources. These bears weigh between 200 and 600 pounds, with males substantially larger than females.
Black bears range across a wider territory than grizzlies, appearing in the Bighorn Mountains, Medicine Bow National Forest, Black Hills region, and various mountain ranges throughout the state. You’re more likely to encounter black bears than grizzlies simply due to their larger population and broader distribution. They’re excellent climbers and will raid campgrounds, vehicles, and homes for food if given the opportunity.
Black bear encounters typically result from improper food storage or attractants like garbage, pet food, or bird feeders near homes. Unlike grizzly bears, black bears are more likely to be deterred by aggressive behavior if they approach you. However, you should never attempt to feed or approach any bear, regardless of species. The Travel Wyoming safety guidelines emphasize maintaining at least 100 yards distance from bears and immediately leaving the area if you spot one.
3. Gray Wolf
The gray wolf (Canis lupus) returned to Wyoming through natural recolonization and reintroduction efforts in Yellowstone National Park during the mid-1990s. These intelligent pack hunters now inhabit northwestern Wyoming, particularly in and around Yellowstone, with occasional sightings in other remote wilderness areas. Adult wolves weigh between 70 and 110 pounds and live in family groups called packs that cooperate to hunt large prey like elk and deer.
Wolf attacks on humans remain extraordinarily rare, with only two fatal attacks documented in North America in the past century. However, wolves have lost some of their natural fear of humans in areas where they’ve become habituated to people, particularly near developed areas in national parks. The primary risk comes from wolves that associate humans with food or become defensive around den sites with pups.
Important Note: Never approach wolf pups or den sites, even if adults aren’t visible. Parent wolves will aggressively defend their young and may attack if they perceive a threat to their pack.
If you encounter wolves while hiking, make yourself appear larger by raising your arms, back away slowly while facing the animals, and never run. Wolves have a strong prey drive and may chase fleeing targets. The presence of wolves creates similar safety considerations to those found in Alaskan wilderness areas, where large predators require constant awareness.
4. Plains Bison
Plains bison (Bison bison bison) are North America’s largest land mammals, with bulls weighing up to 2,000 pounds and standing 6 feet tall at the shoulder. Yellowstone National Park contains the only continuously wild bison herd in the United States, with approximately 5,000 animals roaming the park’s valleys and grasslands. Despite their docile appearance, bison injure more people in Yellowstone than any other animal, causing several injuries each year through charges and gorings.
Bison appear calm and slow-moving, which leads many visitors to dangerously underestimate them. These animals can sprint at speeds up to 35 miles per hour and will aggressively defend their personal space, particularly during the July-August breeding season called the rut. Bulls become especially unpredictable during this period, fighting other males and charging any perceived threats including humans.
According to wildlife safety experts, you must maintain at least 25 yards distance from bison at all times. Warning signs of an impending charge include raised tail, pawing the ground, snorting, and head bobbing. If a bison displays these behaviors, you’re too close and should immediately back away. Running in a straight line won’t work since bison can easily outrun humans—instead, put large obstacles like trees, vehicles, or rocks between yourself and the animal.
5. Mountain Lion (Cougar/Puma)
The mountain lion (Puma concolor) ranks among Wyoming’s most elusive and dangerous predators. These solitary cats inhabit rocky terrain, forests, and canyon country throughout the state, preferring areas with adequate cover for stalking prey. Adult mountain lions weigh between 80 and 150 pounds, with males significantly larger than females. Their muscular build allows them to take down prey much larger than themselves, including deer and elk.
Mountain lion encounters remain rare because these cats actively avoid humans and hunt primarily at dawn, dusk, and nighttime hours. However, attacks do occur, particularly in areas where human development encroaches on lion habitat or when lions are young and inexperienced at hunting natural prey. The greatest risk comes from recreating alone in mountain lion country during low-light conditions when these predators are most active.
If you encounter a mountain lion, never run—this triggers their chase instinct. Instead, face the animal, make yourself appear as large as possible by raising your arms or jacket, maintain eye contact, and back away slowly. If the lion acts aggressively, shout, throw rocks, and fight back vigorously if attacked. Mountain lions are ambush hunters that rely on surprise, so maintaining awareness of your surroundings provides your best defense. Similar mountain lion safety protocols apply throughout the Rocky Mountain region.
6. Moose
Moose (Alces alces) are Wyoming’s largest deer species, with bulls weighing up to 1,200 pounds and standing over 6 feet tall at the shoulder. You’ll find moose in willow thickets, riparian areas, and forests throughout northwestern Wyoming, particularly in Grand Teton National Park, the Bridger-Teton National Forest, and areas near Jackson Hole. Despite their gangly appearance, moose are surprisingly agile and aggressive when threatened.
Moose attacks occur more frequently than many visitors realize, often surpassing bear encounters in some regions. Cows with calves become extremely defensive during late spring and early summer, while bulls grow aggressive during the September-October breeding season called the rut. Unlike many prey animals that flee from threats, moose often choose to stand their ground or actively charge perceived dangers.
Common Mistake: Treating moose like gentle, slow-moving animals leads to dangerous encounters. These massive ungulates can charge without warning and inflict serious injuries with their sharp hooves and sheer body mass.
Warning signs of an agitated moose include pinned-back ears, raised hackles on the neck, and licking of lips. If you notice these behaviors, you’re too close and should retreat immediately while keeping trees or large rocks between yourself and the animal. The Jackson Hole wildlife viewing safety guide recommends maintaining at least 25 yards distance from moose at all times and giving them even more space during sensitive periods.
7. Elk
Elk (Cervus canadensis) are abundant throughout Wyoming, with populations exceeding 100,000 animals across the state. These large deer inhabit mountain meadows, forests, and grasslands from the Bighorn Mountains to the Red Desert. Bull elk can weigh up to 700 pounds and grow antlers spanning 5 feet, making them formidable animals during confrontations. Most elk-related injuries occur during the fall rut when bulls become aggressive while competing for females.
During September and October, bull elk engage in intense competition for breeding rights, bugling loudly and fighting other males with their massive antlers. This hormonal surge makes them unpredictable and potentially dangerous to humans who wander too close to herds. Cow elk also become aggressive when protecting newborn calves in late spring, using powerful kicks to defend their young from perceived threats.
Elk in developed areas like the town of Jackson or Mammoth Hot Springs in Yellowstone have become habituated to human presence, making them potentially more dangerous because they’ve lost their natural wariness. Never position yourself between an elk and escape routes, and maintain at least 25 yards distance at all times. If an elk approaches you, raise your arms, make noise, and back away slowly while watching the animal. These same principles apply when encountering elk and other large ungulates throughout their North American range.
8. Prairie Rattlesnake
The prairie rattlesnake (Crotalus viridis) represents Wyoming’s most widespread venomous reptile, inhabiting grasslands, shrublands, and rocky areas throughout the state except for high mountain elevations. These pit vipers typically measure 3 to 4.5 feet in length and feature brown or greenish coloration with dark blotches along their backs. You’ll encounter prairie rattlesnakes most frequently during warmer months when they’re active and hunting small mammals, birds, and lizards.
Prairie rattlesnakes become most dangerous when you accidentally step near them on trails or reach into rocky crevices where they’re hiding. These snakes rely on camouflage and stillness as their primary defense, only rattling and striking when they feel threatened or cornered. Most bites occur when people attempt to kill, capture, or handle rattlesnakes rather than simply backing away and giving them space.
The venom of prairie rattlesnakes causes severe pain, swelling, and tissue damage but is rarely fatal with proper medical treatment. According to Wyoming wildlife authorities, immediate medical attention at a hospital equipped with antivenom provides the best outcome for snakebite victims. Never attempt to catch, kill, or photograph the snake after a bite—focus on getting to medical care quickly while keeping the bitten limb immobilized and below heart level.
Pro Tip: Watch where you place your hands and feet when hiking in rattlesnake country. Use a walking stick to probe ahead in tall grass, avoid reaching into rock crevices, and wear leather boots that cover your ankles for additional protection.
9. Midget Faded Rattlesnake
The midget faded rattlesnake (Crotalus oreganus concolor) inhabits rocky areas and sagebrush habitats in southwestern Wyoming, particularly in the Green River Basin and areas near Flaming Gorge. This subspecies of the western rattlesnake typically measures 18 to 25 inches in length, making it considerably smaller than the prairie rattlesnake. Their pale coloration with faded markings provides excellent camouflage against sandy soils and light-colored rocks.
Despite their smaller size, midget faded rattlesnakes possess potent venom that causes similar symptoms to other rattlesnake species, including severe pain, swelling, and potential tissue necrosis. Their diminutive size and excellent camouflage make them particularly difficult to spot, increasing the risk of accidental encounters. These snakes often take refuge under rocks, in animal burrows, or within rocky outcrops where they’re nearly invisible.
The limited range of midget faded rattlesnakes in Wyoming means most visitors won’t encounter this species unless recreating in southwestern regions of the state. However, if you’re hiking, climbing, or camping in their habitat, exercise the same caution you would around prairie rattlesnakes. For comprehensive information on Wyoming’s venomous reptiles, visit resources on venomous animals in Wyoming, which covers identification and safety protocols for all dangerous species.
10. Coyote
Coyotes (Canis latrans) thrive throughout Wyoming’s diverse ecosystems, from grasslands and deserts to mountain forests and suburban areas. These adaptable predators typically weigh 25 to 35 pounds and hunt individually or in small family groups. While coyotes rarely attack healthy adult humans, they’ve become increasingly bold in areas where human development encroaches on their territory and food sources are readily available.
The primary risk from coyotes comes from animals that have become habituated to humans through feeding, either intentional or through access to garbage, pet food, or outdoor food sources. Habituated coyotes lose their natural fear and may approach people aggressively, particularly during denning season when protecting pups. Small children and pets face the greatest risk from coyote encounters, as these predators sometimes view them as potential prey.
If you encounter an aggressive coyote, use hazing techniques to restore their natural fear of humans. Shout, wave your arms, throw rocks or sticks near (not at) the animal, and make yourself appear as large and threatening as possible. Never run from a coyote, as this triggers their chase response. According to Wyoming predator safety resources, consistent hazing by entire communities helps maintain coyotes’ natural wariness of people and prevents dangerous situations from developing.
11. Bobcat
Bobcats (Lynx rufus) inhabit forests, canyons, and rocky terrain throughout Wyoming, though their secretive nature makes them rarely observed. These medium-sized cats weigh between 15 and 30 pounds and feature distinctive tufted ears, short tails, and spotted coats. Bobcats are solitary hunters that primarily target rabbits, rodents, and birds, avoiding human contact whenever possible.
Attacks on humans by bobcats are exceptionally rare and typically involve rabid animals or situations where the cat feels cornered with no escape route. Healthy bobcats pose minimal threat to adult humans but may view small pets as prey, particularly in areas where wild prey populations are low. Most negative bobcat encounters occur when people attempt to feed, capture, or photograph the animals at close range.
If you spot a bobcat while hiking or near your property, consider yourself fortunate to observe these elusive predators. Maintain distance, never approach or corner the animal, and keep pets on leashes in areas where bobcats are known to occur.
The same protocols for mountain lion encounters apply to bobcats—make yourself appear large, make noise, and back away slowly while facing the animal. Understanding predator behavior across different regions helps maintain safety, as seen in resources about dangerous animals in Arizona and other western states.
12. American Badger
The American badger (Taxidea taxus) inhabits grasslands, prairies, and open areas throughout Wyoming where they hunt ground squirrels, prairie dogs, and other burrowing mammals. These stocky members of the weasel family weigh 15 to 25 pounds and feature powerful front claws designed for digging. While badgers typically avoid humans, they become extremely aggressive when threatened or cornered, defending themselves with remarkable ferocity.
Badger attacks on humans usually occur when people or dogs accidentally encounter badgers near their burrows or when someone attempts to handle or capture these animals. Badgers possess incredibly strong jaws, sharp teeth, and razor-sharp claws that can inflict serious lacerations and puncture wounds. Their low center of gravity and aggressive temperament make them formidable opponents despite their relatively small size.
Important Note: Never attempt to corner, capture, or handle a badger. These animals will fight aggressively to defend themselves and can inflict severe injuries with their powerful jaws and claws. If you encounter a badger, give it space to retreat.
Most badger encounters happen when people are surprised by these animals emerging from burrows or when dogs chase badgers into defensive positions. Keep dogs on leashes in areas with visible badger activity, indicated by large burrow entrances and excavated earth. If your dog encounters a badger, call them back immediately rather than intervening physically, as badgers can severely injure pets that corner them.
13. Ticks
Several tick species inhabit Wyoming’s grasslands, forests, and shrublands, including the Rocky Mountain wood tick, American dog tick, and brown dog tick. These tiny arachnids pose significant health risks through disease transmission rather than direct physical harm. Ticks in Wyoming can transmit Rocky Mountain spotted fever, Colorado tick fever, tularemia, and tick-borne relapsing fever to humans and animals through their blood-feeding behavior.
You’ll encounter ticks most frequently during spring and early summer months when they’re actively seeking hosts in tall grass, leaf litter, and brush along trails. Ticks crawl onto passing animals or humans, then attach to skin and feed for several days before dropping off. Disease transmission typically requires ticks to remain attached for 24 to 48 hours, making prompt tick removal crucial for preventing infection.
Protect yourself from tick bites by wearing long pants tucked into socks, using EPA-approved insect repellents containing DEET or picaridin, and performing thorough tick checks after outdoor activities. According to Wyoming wildlife health resources, proper tick removal using fine-tipped tweezers to grasp the tick close to the skin and pull straight out reduces infection risk. Similar tick precautions apply when exploring dangerous animals in North Carolina and other tick-endemic regions.
14. Black Widow Spider
The western black widow spider (Latrodectus hesperus) inhabits Wyoming’s lower elevation areas, particularly in southern regions of the state. Female black widows feature the characteristic shiny black body with a red hourglass marking on the underside of their abdomen, while males are smaller and less dangerous. These spiders construct irregular webs in dark, sheltered locations including woodpiles, garages, sheds, and outdoor structures.
Black widow venom contains neurotoxins that affect the nervous system, causing severe muscle pain, cramping, nausea, and difficulty breathing in serious cases. However, bites rarely prove fatal to healthy adults, and only female black widows possess fangs capable of penetrating human skin. Most bites occur when people reach into dark areas where spiders are hiding or when they accidentally press against spiders while moving objects.
Prevent black widow encounters by wearing gloves when handling stored items, woodpiles, or outdoor equipment, and by shaking out shoes, gloves, and clothing that have been stored before wearing them.
If bitten, clean the wound with soap and water, apply ice to reduce swelling, and seek medical attention promptly. Hospital treatment may include pain medication, muscle relaxants, and in severe cases, antivenom to counteract the neurotoxic effects.
15. Brown Recluse Spider
The brown recluse spider (Loxosceles reclusa) is not native to Wyoming, and verified populations do not exist in the state. However, individual spiders occasionally arrive in Wyoming through shipments, moving boxes, or vehicles from states where brown recluse spiders are established. These spiders feature a violin-shaped marking on their cephalothorax and prefer dark, undisturbed areas like closets, storage boxes, and rarely-used spaces.
Brown recluse venom contains enzymes that destroy tissue, potentially causing necrotic lesions that take months to heal in severe cases. The initial bite may go unnoticed, with symptoms developing over hours or days as the venom breaks down skin and underlying tissue. Most bites heal without complications, but some develop into serious wounds requiring medical intervention including antibiotics, wound care, and occasionally surgical debridement.
While the risk of brown recluse encounters in Wyoming remains extremely low compared to states like Kansas, Missouri, or Arkansas, you should still exercise caution when unpacking items shipped from brown recluse-endemic regions.
Inspect boxes carefully, shake out stored items before use, and seek medical attention if you develop an expanding, painful lesion following a suspected spider bite. Understanding regional wildlife risks helps maintain safety across all environments, from Wyoming to dangerous animals in Texas where brown recluse spiders are more common.
Wyoming’s wilderness offers extraordinary opportunities to experience untamed landscapes and observe magnificent wildlife in their natural habitats. However, respecting the power and unpredictability of these 15 dangerous animals ensures your adventures remain safe and memorable.
Whether you’re photographing grizzly bears in Yellowstone, hiking through rattlesnake country, or camping beneath star-filled skies, maintaining awareness of your surroundings and following proven safety protocols protects both you and Wyoming’s remarkable wildlife.
Remember that you’re a visitor in their home—give animals space, store food properly, make noise on trails, and never approach or feed wild animals regardless of how docile they appear.
