Wild black bear close-up at Yellowstone National Park. The photographer wrote, “This big bear was grazing in the late evening near the road just east of Floating Island Lake. He grazed towards my car then gave me a quick look, so I was able to take this from about 20 yards away.” Yellowstone Park Service explained, “67 different mammals live here, including grizzly bears and black bears.” Photo #1 by Pat Gaines

Yellowstone Vista. The Yellowstone Photo Collection lists all of these animals: Badger, bat, beaver, bighorn sheep, bison, black bear, bobcat and lynx, chipmunk, cottontail rabbit, coyote, deer, domestic dog, elk, flying squirrels, fox, grizzly bear, ground squirrel, hare & jackrabbit, marmot, mice, moose, mountain goat, mountain lion, muskrat, other rodents, otter, pika, pine martin, pocket gopher, porcupine, prairie dog, pronghorn antelope, skunk, tree squirrels, voles, weasels, minks, ferrets, wolverines, wolves. Photo #2 by Susan Renee

Bison herd at mud pots across the river from Mud Volcano. According to the 2013 Yellowstone Trip Planner (.pdf), “Big as they are, bison can sprint three times faster than humans can run. No vacation picture is worth personal injury. Your best view may be from inside a hard-sided vehicle.” If you are interested, then here’s more about American Buffalo Traffic Jams: Bison of Yellowstone National Park. Photo #3 by Diane Renkin / Yellowstone National Park Service

Yellowstone Wolf in Woods. About Yellowstone mammals, NPS wrote, “Wild animals, especially females with young, are unpredictable and dangerous. Keep a safe distance from all wildlife.” Photo #4 by Jeremy Weber

Black bear cub digging into the old log for grubs and ants. Yellowstone Park Service explained, “Yellowstone is home to the largest concentration of mammals in the lower 48 states. Sixty-seven different mammals live here, including grizzly bears and black bears. Seven native ungulate species—elk, mule deer, bison, moose, bighorn sheep, pronghorn, and white-tailed deer live here. Non-native mountain goats have colonized northern portions of the park and numerous small mammals are found throughout the park.” Photo #5 by Pat Gaines

Bull elk bugling in the Gibbon Meadow in the Yellowstone National Park. NPS stated, “Each year a number of park visitors are injured by wildlife when approaching too closely. Approaching on foot within 100 yards (91 m) of bears or wolves or within 25 yards (23 m) of other wildlife is prohibited. Please use roadside pullouts when viewing wildlife. Use binoculars or telephoto lenses for safe viewing and to avoid disturbing them.” Photo #6 by Erwin & Peggy Bauer / U.S. Fish and Wildlife Service

Twenty five minute old elk calf in Mammoth Hot Springs. Bold print on NPS, It is illegal to willfully remain near or approach wildlife, including birds, within ANY distance that disturbs or displaces the animal. Photo #7 by Jim Peaco / Yellowstone National Park Service

Grizzly bear on Swan Lake Flats. Before you visit Yellowstone, please do read up on NPS advice first. For example, NPS states, “If The Bear Stands up on Two Legs: Some people mistakenly believe that when a bear rears up onto two legs that the bear is about to charge, that rearing up on two legs is an aggressive posture that means the bear is going to attack (people have learned this from Hollywood Movies), THIS IS NOT TRUE! When a bear stands up on two legs it is trying to gather more information about what you are and what your intentions are. Bears gather this information through a combination of scent, sight, and sound. Standing up on two legs improves the bears ability to gather sight and scent information. This is a good time to start backing away, talking to the bear in a calm voice, and letting the bear know that you are a person and that you mean no harm to the bear or its cubs.” Photo #8 by Jim Peaco / NPS

Leopold wolf following grizzly bear. Photo #9 by Doug Smith / Yellowstone National Park Service

Red fox in Lamar Valley. NPS History states, “The human history of the Yellowstone region goes back more than 11,000 years. From then until to the very recent past, many groups of Native Americans used the park as their homes, hunting grounds, and transportation routes. These traditional uses of Yellowstone lands continued until a little over 200 years ago when the first people of European descent found their way into the park. In 1872 a country that had not yet seen its first centennial, established Yellowstone as the first national park in the world. A new concept was born and with it a new way for people to preserve and protect the best of what they had for the benefit and enjoyment of future generations.” Photo #10 by Jim Peaco / Yellowstone NPS

Wolf in Lamar Valley. NPS Did you know? “There were no wolves in Yellowstone in 1994. The wolves that were reintroduced in 1995 and 1996 thrived and there are now over 300 of their descendants living in the Greater Yellowstone Area.” Photo #11 by Jim Peaco / Yellowstone National Park Service

The photographer said, “I took this photo in the wee hours of the morning.” Photo #12 by Steve Wall

Mountain lion climbing down rock. According to Wikipedia, “The mountain lion (Puma concolor), also called the cougar, is the largest member of the cat family living in Yellowstone. Mountain lions can weigh up to 200 pounds (~90 kg), although lions in Yellowstone are thought to range between 140 and 160 pounds (~65 and ~70 kg) for males and around 100 pounds (45 kg) for females. Two to three kittens may be born at any time of year, although most arrive in summer and fall. For reasons that are not clear, only about 50 percent of kittens survive their first year. The current population of lions in Yellowstone is estimated to be 18-24 animals and is thought to be increasing. Mountain lions live an average lifespan of about 12 years in the wild.” Photo #13 by K Fink / NPS

The other mammals of Yellowstone. The photographer called this “The Badgerazzi. There was over $100K in glass pointed at a badger hole just off the road up in the Lamar Valley. These guys were out at dawn and there until dusk, waiting for the poor badger to show up. I dropped by on 5 separate occasions hoping to see the badger, but would loose patience after about 30-45 minutes of staring at the dirt. I guess that’s what separates the great nature photographers from the rest of us! That, and about 10K in gear!” Photo #14 by Pat Gaines

Screeching mammoth ground squirrels. Uinta Ground Squirrels live only in the states surrounding Yellowstone National Park. The photographer stated, “If you stay at the cabins at Mammoth Hot Springs, you’ll be living in a colony.” Photo #15 by Carol Vinzant & #16 by Carol Vinzant

The photographer wrote, “I dont know why anyone would find this beautiful animal ‘scary’ or a nuisance. I have seen coyotes up close and they are beautiful, bold and independent animals. All qualities admired in humans but not in animals by the conventional mindset.” Photo #17 by numbphoto

Bald eagle along the Yellowstone River in Hayden Valley. Thus spake Wikipedia: “Since the creation of the park in 1872, 318 species of birds have been documented within its boundaries.[16] Although Yellowstone is not a birding mecca because of its high altitude and cold winters, it is home to a variety of interesting bird species that attract visitor attention every year. The park has a good resident population of Bald Eagles, Trumpeter Swans, Common Loons, Ospreys, American White Pelicans, and Sandhill Cranes.” Photo #18 by Jim Peaco / NPS

Trumpeter Swan with unfolded wings. Photo #19 by Alan Vernon

The photographer wrote, “A momma grizzly up near Mammoth Hot Springs has four cubs this year. It is rare for a grizz to have so many – this is only the 3rd time in park history that this has been documented. One of the other times was a case where one had adopted two cubs from a mother that had died. In this case, all four were from the same mother (not sure how they know this). The bears were hanging around a pond just North of Mammoth Hot Springs, but then headed West across the road towards Swan Flats. This is them crossing the road on Monday. Note that one of the bears is much lighter in color than the others. I wonder if it is a case of 3 identical twins with one fraternal?” Photo #20 by Pat Gaines

The quiet way to show, “I spent a few days in Yellowstone.” Yellowstone Park Service explained, “Seven native ungulate species—elk, mule deer, bison, moose, bighorn sheep, pronghorn, and white-tailed deer live here.” Photo #21 by NaturesFan1226

Plains bison in winter at Yellowstone National Park. NPS reported that “the bison population fluctuates from 2300 to 4500 animals.” Did you know? “There are more people hurt by bison than by bears each year in Yellowstone. Park regulations state that visitors must stay at least 25 yards away from bison or elk and 100 yards away from bears.” Photo #22 by Jim Peaco / NPS via USGS

130 pound wolf watches biologists in Yellowstone National Park after being captured and fitted with a radio collar on 1-9-03. Photo #23 by William Campbell / U.S. Fish and Wildlife Service

Stampede of the Wild Horses. The photographer wrote, “After a long hike through the mountains of Yellowstone, I came across over 40 horses sprinting from one meadow to the next. I stepped behind a tree to get out of the way and shot this one.” Photo #24 by Trey Ratcliff

Yellowstone sign warning that wildlife in the park is not tame. In fact, NPS advises (pdf): “If any wild animal changes its behavior due to your presence, you are too close. Do not approach wildlife, no matter how tame or calm they may appear to you in the moment.” Photo #25 by NPS

Apparently when 2,000 pounds of buffalo wants to walk on the road, he or she makes the rules. There were dozens of images of buffalo sharing the road with Yellowstone tourists. This photographer’s story “Looking death in the eye” was rather amusing. “I rounded a corner near Gibbon Falls in Yellowstone Park early one morning and encountered about 10 buffalo blocking the road. I pulled off to the side – they started approaching my rental car and I wasn’t sure what to do as the car behind me blocked my exit. The lead buffalo, the one in the center, came to within 6 inches of the drivers side window, stopped for a bit, and snorted at me. The others gathered around, completely surrounding my car. The lead buffalo started moving – but 2 seconds later it was whump, whump, whump – he was hip-checking the back of the car! It felt like an earthquake. All I could think of was how to explain it to the rental car company – yes, my car was damaged by a hip-checking buffalo – but there was no damage, just a lot of dirt and buffalo hair – what a strange experience!” Photo #26 by Frank Kovalchek

Grizzly Bear in Field. The park service tells visitors: “Safe traveling in bear country begins before you get on the trail. Learning about bears before you come to the park can help you avoid a confrontation. Read about bear spray and what to do if you encounter a bear. When you arrive at the park, check at the nearest backcountry office or visitor center.” There is a plethora of bear information and videos that visitors should watch before they arrive at Yellowstone.” Photo #27 by Terry Tollefsbol / U.S. Fish and Wildlife Service

Wolverine. Yellowstone Park Service explained, “Wolverine and lynx, which require large expanses of undisturbed habitat, are also found in the Yellowstone ecosystem.” Photo #28 by NPS

Mountain goat with Cutoff Peak in the background. Yellowstone Park Service explained, “Non-native mountain goats have colonized northern portions of the park and numerous small mammals are found throughout the park.” Photo #29 by Nathan Varley / NPS

Big horn sheep. NPS mammals explained, “Annual surveys of bighorn indicate that the resident herd on Yellowstone’s northern range consists of at least 150-225 animals. In 1997, a new study done by researchers at Montana State University began to investigate bighorn population status and behavior in northern Yellowstone. Of particular interest to these investigators is the effect of road use on the bighorns’ ability to use their summer and winter range. Sheep are commonly seen along the road through the Gardner River Canyon, where visitors should be alert for bighorns crossing between their preferred cliffs and the river where they drink.” Photo #30 by William S Keller / NPS

American Badgers. Photo #31 by Yathin

Buffalo Snort. Photo #32 by Matthew Paulson

Grizzly Bear: “Bears may be seen in Yellowstone March through November. Yellowstone is one of the only areas south of Canada that still has large grizzly bear populations.” Visitors to Yellowstone are required to keep food and garbage in a bear-proof manner. Visitors are also advised to stay in groups of three or more people and make a noise if you can’t see far ahead. You must be alert for bears. The 2013 Yellowstone Trip Planner (.pdf) states: “Do not run from a bear. Carry bear spray and take time to learn how to use it safely and effectively. If you have a surprise encounter with a bear, do not run. Slowly back away. If a bear charges, stand your ground and use your bear spray. It has been highly successful at stopping aggressive behavior in bears. If a bear charges and makes contact with you, fall to the ground onto your stomach and ‘play dead‘.” Photo #33 by Terry Tollefsbol / U.S. Fish and Wildlife Service

Bull bison crossing Yellowstone River. Answer to the frequently asked NPS questions: “Yellowstone is the only place in the United States where bison have lived continuously since prehistoric times. A number of Native American tribes especially revere Yellowstone’s bison as pure descendants of the vast herds that once roamed the grasslands of the United States. The largest bison population in the country on public land resides in Yellowstone. It is one of the few herds free of cattle genes.” Photo #34 by Jim Peaco / Yellowstone National Park Service

Pika in Yellowstone. Wikipedia says, “As they live in the high and cooler mountain regions, they are very sensitive to high temperatures, and are considered to be one of the best early warning systems for detecting global warming in the western United States. Temperature increases are suspected to be one cause cause of American pikas moving higher in elevation in an attempt to find suitable habitat, as well as cooler temperatures. American pikas, however, cannot easily migrate in response to climate change, as their habitat is currently restricted to small, disconnected habitat ‘islands’ in numerous mountain ranges. Pikas can die in six hours when exposed to temperatures above 25.5°C (77.9°F) if individuals cannot find refuge from heat.” Photo #35 by JR Douglass / NPS

Mule deer. “Both mule and white-tailed deer live an average lifespan of 10 to 15 years in the wild” at Yellowstone. For a coolness factor, you can watch Old Faithful Area Live-Streaming Video WebCam. Photo #36 by George Marler / NPS

Young moose walking. NPS states, Moose “were reportedly very rare in northwest Wyoming when Yellowstone National Park was established in 1872. Subsequent protection from hunting and wolf control programs may have contributed to increased numbers but suppression of forest fires probably was the most important factor, since moose here depend on mature fir forests for winter survival.” Also, “the moose calf crop has been declining since the fires of 1988.” Photo #37 by Ryan Hagerty / U.S. Fish and Wildlife Service

A female grizzly bear family rambles through the park. “USGS researchers study population dynamics of these bears, as well as hazards they face. This information is used by resource managers and decision makers.” Photo #38 by Kim Keating / U.S. Geological Survey

Cool USGS thermal image series of wolves at Yellowstone. Top: “A wolf howls in this thermal image of a captive wolf at the Grizzly and Wolf Discovery Center in West Yellowstone. USGS scientists are examining thermal imagery of wolves as one step in assessing impacts of sarcoptic mange on the survival, reproduction and social behavior of this species in Yellowstone National Park. All research animals are handled by following the specific requirements of USGS Animal Care and Use policies.” Lower left: “Note the bright red patch on the wolf’s hindquarters in this thermal image of a captive wolf at the Grizzly and Wolf Discovery Center in West Yellowstone. This is where fur was shaved to replicate the loss of fur associated with sarcoptic mange.” Lower right: “Adho mukha svanasana is the Sanskrit name for the downward facing dog yoga asana and this wolf shows how the pose got its name. The wolf’s eyes, muzzle and paw tips are warm and yellow in this thermal image of a captive wolf at the Grizzly and Wolf Discovery Center in West Yellowstone.” Photo #39 by U.S. Geological Survey & #40 by U.S. Geological Survey & #41 by U.S. Geological Survey

Mountain lion in yellow aspens. “Mountain lions are rather secretive, consequently, most visitors are unaware of their existence in Yellowstone. Lions probably live throughout the park in summer.” Photo #42 by WL Miller / NPS

Mama and cubs stop traffic. Photo #43 by dylans mom

Porcupine, wildlife at Yellowstone. Photo #44 by NPS

Pine marten. According to Wikipedia, “There are at least 50 small mammal species known to occur in Yellowstone National Park, including four common species of bats: Big Brown Bat, Little Brown Bat, Long-legged Bat, and Silver-haired bat. Squirrel, Rabbit, vole, mice, and shrew species are common, but many are nocturnal and rarely seen by visitors. The Uinta ground squirrel, Least Chipmunk, Golden-mantled ground squirrel and American Red Squirrel are commonly encountered by park visitors.” Photo #45 by DL Coe / NPS

A Moose Hidden in the Snow. As you can see on the National Park Service map (.pdf), Yellowstone and Teton National Parks are neighbors. The photographer had this tagged as both, but explained, “A Shiras Bull Moose lays down in the sage brush of Antelope Flats during a light winter flurry. Taken in Grand Teton NP, WY.” Photo #46 by Chase Dekker

Otter pups in the water at Yellowstone. The photographer wrote, “Somebody’s tail is about to be chomped.” Photo #47 by Pat Gaines

Little Bighorn. The photographer added, “Big-ness and horns not included. This lamb was trotting up a mountain road in Yellowstone National Park with the rest of its family.” Photo #48 by Matt Hintsa

Gorgeous growling wolves. NPS has the history of wolves at Yellowstone. Photo #49 by Jeremy Weber

Pronghorn antelope in Gardiner, Montana Yellowstone’s Photo Collection. “Early accounts of pronghorn in Greater Yellowstone described herds of hundreds seen ranging through most major river valleys. These populations were decimated by 1900, and declines continued among remaining herds. On the park’s northern range, pronghorn declined from 500-700 in the 1930s to about 122 in 1968. By 1992 the herd had increased to 536.” Photo #50 by William S Keller / NPS

Yosemite Sam used to mutter about ‘yellow-bellied marmots;’ this one is in Yellowstone. Photo #51 by Miller / NPS

Meadow vole. “A vole is a small rodent resembling a mouse but with a stouter body, a shorter, hairy tail, a slightly rounder head, smaller ears and eyes. …The average life of the smaller vole species is three to six months,” according to Wikipedia. Photo #52 by Gillian Bowser / NPS

Muskrat in the Yellowstone River. “Muskrats are most active at night or near dawn and dusk.” Photo #53 by Harry Engels / NPS

Grizzly bear sow & cub with radio neckband. Photo #54 by John Good / NPS

Bighorn Sheep near Tower. Photo #55 by Eeekster

Elk near Roaring Mountain. “More than 30,000 elk from 7-8 different herds summer in Yellowstone and approximately 15,000 to 22,000 winter in the park,” wrote NPS. Photo #56 by NPS

Mule deer doe & fawn. Photo #57 by J Schmidt / NPS

Skunk near Geode Creek. Photo #58 by Kevin Topping

Grizzly sow with three cubs on carcass at Alum Creek.” Photo #59 by Jim Peaco / NPS

Stand off, wolves at Yellowstone. Photo #60 by Doug Smith NPS