When Do Bears Come Out of Hibernation in Wyoming? What You Need to Know

Wyoming is one of the few places in the lower 48 states where you can encounter both grizzly bears and black bears in the wild — and spring is when that reality becomes most relevant for anyone heading outdoors. As the snow melts across mountain valleys and the first green shoots push through the soil, bears are stirring in their dens and preparing to re-enter the world after months of winter sleep.

Understanding when bears come out of hibernation in Wyoming, what drives their timing, and how their behavior shifts in the weeks after emergence can make a real difference in how safely you experience the state’s remarkable backcountry. Whether you’re planning a trip to Yellowstone, hiking the Bridger-Teton, or simply living near bear country, this guide gives you what you need to know.

When Do Bears Hibernate in Wyoming

Bears in Wyoming don’t simply flip a switch and fall asleep — their transition into hibernation is gradual and closely tied to food availability, temperature, and snowfall. The process begins in earnest during the fall months, when bears enter a phase called hyperphagia: a period of intense calorie-loading where they consume enormous amounts of food to build fat reserves for winter.

During hyperphagia, a bear may consume up to 20,000 calories per day, building up fat reserves that will sustain them through months of winter sleep. Once those reserves are in place and temperatures drop, bears begin seeking out den sites.

Key Insight: Bears don’t truly hibernate in the deepest physiological sense. They enter a state called torpor — a lighter sleep during which their heart rate drops, metabolism slows dramatically, and body temperature decreases slightly. Unlike true hibernators, a bear can be roused from torpor if disturbed.

Most black bears enter winter dens by the end of October, with most grizzly bears doing the same during the month of November. A small number of grizzly bears have learned how to put on additional fat during late fall and early winter and will remain out and about for up to another month.

During torpor, a bear’s heart slows to between 8 and 12 beats per minute — about a third of its normal rate. It takes a breath once, maybe twice a minute, and body temperature is reduced from 98 to about 90 degrees Fahrenheit. Despite this dramatic slowdown, bears maintain a body temperature close to normal during hibernation, which lets them react to danger and sources of food faster than many other hibernating animals.

One of the most remarkable aspects of bear torpor is what happens to their bodies over those long winter months. Not only do muscles not atrophy, but the bear is able to lose weight — about 15 to 30 percent of its body weight — and actually add muscle while sleeping for months. Grizzly bears and black bears generally do not eat, drink, defecate, or urinate during hibernation, living off a layer of fat built up during summer and autumn.

When Do Bears Come Out of Hibernation in Wyoming

Spring emergence in Wyoming is one of the most anticipated wildlife events of the year — and it follows a fairly predictable schedule, though exact timing shifts based on elevation, snowpack, and winter severity. If you’re spending time outdoors from March onward, you should consider yourself in active bear country.

Male grizzlies come out of hibernation in early March, while females with cubs emerge in April and early May. Black bears den at lower elevations and therefore wake earlier, typically in late February. Sometimes, if there is a warm winter and food is available, black bears might emerge out of their dens to eat.

Important Note: After an unseasonably warm winter, bears may come out of hibernation as early as January or February. Warm spells can trigger early emergence regardless of the calendar date, so don’t assume you’re safe from bear encounters in late winter.

Recent years offer a reliable illustration of this timeline. The season’s debut sighting in Yellowstone happened on March 14 in 2025, March 3 in 2024, and March 7 in both 2023 and 2022. In 2026, scientists saw the first bear of the year on March 9 — a grizzly spotted deep in the park’s backcountry, feeding on the remains of a bull bison near Yellowstone Lake.

The first routine grizzly bear sightings of 2024 in Jackson Hole began March 21 on the Bridger-Teton National Forest, followed by Grand Teton National Park’s first bear sighting on March 26. The frequency of bear sightings increased as the winter snowpack disappeared.

The Wyoming Game and Fish Department confirms this general window. Bears begin to emerge from their dens as early as March, groggily in search of spring’s early green grasses and winter-killed ungulates to eat — making it important to be bear aware when recreating in Wyoming’s bear country throughout the spring season.

You can also explore when bears come out of hibernation in Idaho, Wyoming’s western neighbor and part of the same Greater Yellowstone Ecosystem, for a helpful regional comparison.

Which Bear Species Are Found in Wyoming

Wyoming is one of the most bear-rich states in the contiguous United States, and knowing which species you might encounter is essential for both appreciation and safety. Wyoming is home to two species of bears — black bears (Ursus americanus) and grizzly bears (Ursus arctos) — and these two species differ in their habitat preferences, behaviors, and physical attributes.

Black Bears

Black bears are found throughout forested areas and periphery riparian habitats of Wyoming, with local densities depending on habitat quality. They have been managed as a game species in Wyoming since the mid-1970s, and since that time, many black bear populations have increased, with some expanding their distribution.

Black bears are considerably more adaptable than grizzlies when it comes to terrain. They tend to favor lower-elevation forests and are more commonly encountered near developed areas, campgrounds, and trail corridors. The current estimate of the black bear population in the Greater Yellowstone Ecosystem is between 500 and 650.

One important note: don’t rely on color alone to identify a black bear. Black bears in Wyoming can range from jet black to cinnamon to blonde. To identify a bear in Wyoming, look for a combination of the most reliable characteristics — neither color nor size should be used for identification alone.

Grizzly Bears

Grizzly bears are a symbolic icon of wilderness in Wyoming and a wildlife conservation success story. Wyoming has always been home to grizzly bears, and conservation efforts have successfully recovered this population from the brink of extirpation. Grizzly bear populations are now thriving in Wyoming, with high densities existing throughout suitable habitat for the species.

Grizzly bears can be found throughout northwest Wyoming and exist in high densities throughout suitable habitat. Grizzly bears found in Wyoming are part of the Yellowstone area grizzly bear population, and while Wyoming has the majority of grizzly bears in the ecosystem, parts of this population also inhabit eastern Idaho and southern Montana.

According to Wyoming Fish and Game, roughly 700 grizzly bears are thought to exist in the core of the 20-million-plus protected acres of the Greater Yellowstone Ecosystem, which includes Jackson Hole, Grand Teton, and Yellowstone national parks.

Pro Tip: Grizzly bears can be distinguished from black bears by longer, less curved front claws, humped shoulders, and a more concave facial profile. Learning these physical differences before your trip could matter in an encounter situation.

Grizzly bear populations have biologically recovered in Wyoming; however, grizzly bears are currently listed as a threatened population under the Endangered Species Act. For a deeper look at grizzly biology, behavior, and range, the brown bear profile covers their natural history in detail. You can also learn about different types of bears found across North America for broader context.

What Bears Do Immediately After Hibernation in Wyoming

The first few weeks after a bear leaves its den are a fascinating and sometimes dangerous period. Bears don’t simply wake up fully alert and ready to charge — their re-entry into the world is gradual, disoriented, and driven almost entirely by the need to find food.

After spending the winter sealed inside dens, their bodies slowed to a biological crawl, bears step back outside lighter — sometimes 30 percent lighter — and very, very hungry. When bears emerge from their dens, they search for available foods and often scavenge animals that died during the winter.

Interestingly, that hunger doesn’t translate immediately into frantic feeding. Kerry Gunther, who leads Yellowstone’s bear management program, explained: “When they first come out, they don’t eat that much and they are lethargic. For a week or two, they spend more time sleeping on the carcass than eating it. Their metabolisms are not totally kicked in — they are in a kind of walking hibernation.”

Important Note: Just because a bear has emerged doesn’t mean it’s fully alert and predictable. Newly emerged bears experience a period called “walking hibernation” lasting two to four weeks, during which their metabolism is still ramping up and their behavior can be sluggish and unpredictable.

As metabolism kicks in, bears become increasingly focused on calorie-dense food sources. Spring visitors skiing, snowshoeing, or hiking in Yellowstone are reminded to carry bear spray and be especially alert for bears near carcasses and areas with early spring green-up, as these are the first foods sought out by grizzlies after emerging from hibernation.

Bears emerge from hibernation extremely hungry and often feed on winter-killed animals, which they may aggressively defend. This territorial behavior around food sources is one of the most significant risk factors for spring hikers and backcountry travelers in Wyoming.

Female bears with cubs face their own post-hibernation challenges. Cubs are born during the den period and emerge in spring as small, curious animals still very much dependent on their mothers. A female bear gives birth to one to three cubs in midwinter, six to eight weeks after denning. A mother bear with cubs is among the most potentially dangerous wildlife encounters you can have in Wyoming — give her the widest possible berth.

If you’re curious how post-hibernation behavior compares across states, see how bears emerge in Colorado or what the emergence season looks like in California’s bear country.

Bear Activity Hotspots to Watch in Wyoming

Wyoming’s bear country is vast, but certain areas consistently see the highest levels of bear activity — particularly in the weeks and months following spring emergence. Knowing where bears concentrate helps you prepare appropriately, whether you’re hiking, camping, or simply driving through.

Yellowstone National Park

Yellowstone is the epicenter of grizzly bear activity in the lower 48 states. The park’s open meadows, river corridors, and abundant wildlife make it prime habitat year-round. Spring emergence sightings in Yellowstone — documented annually by the National Park Service — reliably begin in early to mid-March, with activity ramping up through April and May as more bears leave their dens at higher elevations.

Despite this, all of Yellowstone is grizzly country, so it is important to come prepared with bear spray. The Hayden Valley, Lamar Valley, and Pelican Valley are among the most productive areas for bear sightings, but encounters can happen anywhere in the park.

Grand Teton National Park and Jackson Hole

As the grizzly bear population expanded within the Greater Yellowstone Ecosystem, bears dispersed across their historical range and into proximity to more populated areas. All of Teton County is now in occupied grizzly bear habitat.

Specific hotspots within Grand Teton include Pilgrim Creek and Signal Mountain Road. You can spot grizzly bears by driving along Signal Mountain Road or exploring the Pilgrim Creek area in spring or fall. In summer, bears are also seen on Togwotee Pass and Turpin Meadows. For black bears, try hiking around Phelps or Jenny Lake.

In spring, grizzlies frequent Willow Flats to feed on new vegetation or scavenge winter-killed animals. Pilgrim Creek is prime grizzly habitat, particularly in late spring and early summer when bears forage in meadows. During late summer, they move into berry patches along the creek, feasting on chokecherries and hawthorn to prepare for hibernation.

Shoshone National Forest and the Beartooth Highway Corridor

The Shoshone National Forest, between Silver Gate and Beartooth Lake, is especially high in grizzly bear activity. In summer, bears forage on slopes and meadows, digging for roots and insects or grazing on lush vegetation. Visitors traveling this stretch should remain vigilant, especially during dawn and dusk, when bear activity peaks.

Bridger-Teton National Forest

Grand Teton National Park experienced a surge of incidents involving black bears, particularly around lakeshore areas, in recent years. Similarly, the Bridger-Teton National Forest saw an increase in black bear activity around the Teton Pass trail system outside of Wilson. Food storage regulations apply across Yellowstone National Park, Grand Teton National Park, Bridger-Teton National Forest, and Caribou-Targhee National Forest during bear-active months.

Pro Tip: South-facing slopes are among the first places to see spring bear activity in Wyoming. Snow melts earlier on these exposures, producing the fresh green vegetation bears crave after emerging from their dens — making these slopes natural gathering points in March and April.

For comparison with a neighboring state that shares much of the same ecosystem, see our guide on other wildlife activity in Wyoming and check out the bear emergence timeline in Maine for a look at how eastern bear populations compare.

How to Stay Safe During Bear Season in Wyoming

Bear encounters in Wyoming are not inevitable — but they are possible any time you’re in bear country from March through November. The good news is that most encounters can be prevented with the right habits, and even close encounters can be managed safely if you know what to do.

On the Trail

• Carry bear spray and know how to use it. Prepare for a bear encounter by carrying bear spray, knowing how to use it, and keeping it accessible. It should be on your hip or chest harness — not buried in your pack.
• Make noise as you hike. Making noise in low-visibility areas and being alert to your surroundings can reduce the likelihood of surprising a bear. If bears know people are nearby, they will often move away without conflict.
• Hike in groups. Hike or ski in groups of three or more, stay on maintained trails, and make noise.
• Avoid dawn, dusk, and night travel. Avoid hiking at dusk, dawn, or at night, when bears are most active and visibility is reduced.
• Stay 100 yards away. Yellowstone and Grand Teton National Park guidelines require people to remain 100 yards from predators like grizzlies. Use binoculars or a telephoto lens to observe bears from a safe distance.

Food Storage and Camp Safety

• Never leave food unattended. Store food, garbage, barbecue grills, and other attractants in hard-sided vehicles or bear-proof food storage boxes.
• Use bear boxes where available. The Bear Box Program keeps bears wild and visitors safe by implementing bear-resistant food storage lockers at campsites throughout Grand Teton National Park. Bear boxes allow visitors to easily store food, garbage, pots and pans, cosmetics, and pet food.
• Secure attractants at home too. Bears can be attracted to anything associated with human or domestic animal foods, including coolers, cooking equipment, bird feeders, and pet dishes, when they are easily accessible.
• Remember: a fed bear is a dead bear. By properly storing attractants, people can help ensure that a bear does not obtain a food reward. Once a bear becomes conditioned to human foods, it is likely to exhibit increasingly bold behavior, which increases risks to both the bear and humans and limits management options.

If You Encounter a Bear

Important Note: Your response to a bear encounter depends on the species and the situation. The correct response for a grizzly attack differs from the correct response for a black bear attack — knowing the difference in advance could save your life.

• Do not run. Do not run if you encounter a bear. Running can trigger a chase response.
• Stay calm and speak in a calm, firm voice. Back away slowly if the bear has not noticed you, or stand your ground if it has.
• If a grizzly attacks: play dead. If a brown or grizzly bear attacks you, leave your backpack on and play dead. The NPS suggests lying flat on your stomach with your hands clasped behind your neck and spreading your legs to make it harder for the bear to turn you over.
• If a black bear attacks: fight back. If a black bear attacks you, do not play dead — try to escape to a secure place, such as a car or building. If escape isn’t possible, fight back aggressively.
• Report all encounters. Report bear sightings and encounters to a park ranger immediately.

Understanding bear behavior in other states can also sharpen your awareness. See how bear season unfolds in Massachusetts, Connecticut, and Kentucky for a broader picture of how black bears behave across different climates. You can also learn more about natural predators of bears and what animals eat bears to better understand their place in the ecosystem.

Wyoming’s bear country is extraordinary — a place where true wilderness still exists and large predators roam freely. Respecting that wildness, staying informed about seasonal bear activity, and following established safety practices allows you to enjoy everything the Cowboy State has to offer while keeping both yourself and the bears safe.