Rocky Mountain mammal size comparisons

In this NPS photo below of a Yellowstone wildlife montage by Robert ‘Bob’ Hynes, you can compare the difference in size / heights of various animals / birds we may see on the Outdoor Club trips to Grand Teton National Park.

Animals, (left to right): a Coyote, a Mule Deer, a Bighorn sheep, a Bull elk, a Wolf, a Grizzly bear and cub, a Bull Moose, a Uinta Ground Squirrel, a Black bear, a Bison and calf, a Marmot, a Pika, and a Pronghorn (antelope)

At the top of the illustration are, in flight, an Osprey on the far left, then past the moose antlers, (left to right) an American White Pelican, a Lesser Scaup, two Trumpeter Swans, and above them, a Green-winged Teal. (Grand Teton birds has close-up photos of some of them.)

NPS photo Yellowstone wildlife montage Robert Hynes 560 pxls:

And in a drawing (not to quite the same scale) of (left to right) a deer, elk, moose and a man you can make a comparison of the difference in size / height of various mammals versus a human.


and in a third, not to quite the same scale, a comparison of the sizes of a wildlife of Mount Rainier National Park, at the top a Clark’s Nutcracker in flight, below it, an Elk, Mountain Goat, Black Bear, Hoary Marmot (left) and Chipmunk (right).

animals and a bird

and a fourth drawing, also not to the same scale, shows, left to right, comparison of heights and sizes / proportions of Big Horn Sheep, Elk, Bear and Moose as seen from the side:

standing Big Horn Sheep, Elk, bear and Moose as seen from the side


More photos and descriptions of most of the animals above are below at this webpage.



elk (5 foot tall) compares in size to a horse.

nps elk bugling: photo of an elk with it's mouth open, looking as though it is bugling earlymorningsmallelkherd80pixels:

Yellowstone park notes:

Elk “Antlers are usually symmetrical and occur on males and, only rarely, females.

•The average, healthy, mature bull has six tines on each antler, and is known in some parts of the US as a “ six point ” or “ six by six. ”

•One-year-old bulls grow 10–20-inch spikes, sometimes forked.

•Two-year-old bulls usually have slender antlers with four to five points.

•Three-year-old bulls have thicker antlers.

•Four-year-old and older bulls typically have six points; antlers are thicker and longer each year.

•Eleven- or 12-year-old bulls often grow the heaviest antlers; after that age, the size of antlers generally diminishes.”

A 23 minute old elk:

elk calf and cow



Moose are 6.5 to 7.5 feet tall, (one source says 5 1/2 to 7 1/2 feet at the shoulder) with antlers that spread 4 to 5 feet (record 6’9″) and can weigh up to 1,400 pounds (usually 1,000 male, 900 female (cow). Lives up to 20 years.

NPS photo of moose in comparison to a SUV:

bull moose and SUV NPS photo:

moose calves2 moose calves crossing a stream

moose pair

male and female moose



Below mountain goat nanny and kid:

mountain goat and kid on steep rock face

Mountain goats (5 foot long, 3 feet tall), black horns are much smaller than bighorn sheep (6 feet tall / 3 1/2 feet to shoulder, muscular male bighorns can weigh over 300 pounds. Females are roughly half this size.):

mountngoatonridgeNPSphoto: bighornsheeplooking NPS photo: NPS photo bighorn sheep 100 pixels: a bighorn sheep from the side

NPS photo pronghorn: Pronghorn Male (buck) weighs 100–125 pounds; female (doe) weighs 90–110 pounds, adult length is 45–55 inches and height is 35–40 inches at shoulder. (can run 30 mph for 15 miles with spurts up to 70 mph, another surce says can run for sustained sprints of 45–50 mph) from the Smithsonian “communicate with each other visually by raising the mane on the back of the neck into a stiff brush and erecting the white hairs on their rump”)

Newborn pronghorn fawns can walk within 30 minutes of birth and are capable of outrunning a human in a couple of days.
The park service notes that “A pronghorn buck (male) is easily distinguished from a doe (female) by his black cheek patch.”

pronghorn buck NPS photo



Both male and female bison 4-5 feet tall at their shoulder, 10-12 feet long, have a small beard, but only the male has a bushy forehead. Males (2,000 lbs/900 kg) are larger than females (1,100 lbs/500 kg).

Yellowstone park says:

Q: How do you tell male from female bison?

A: A bull’s head is wider and shaped more like a triangle than the female bison; its ‘forehead’ fur is much thicker, as is the fur on its forelegs; and its beard is thicker. A cow’s horns are slightly more curved and slender than a bull’s. In addition, a cow’s shoulders are narrower than its hips while a male’s shoulders are broader than its hips.

In the NPS photo below, the female bison is on the left, the male on the right.

female and male bison

baby bison butts head with adult

Bison calves are born with a reddish coat that darkens after the first months:

bison calf

In this photo of a bison about to cross a road, note the size of the bison in comparison to the people and their cars. If the bison decided to change his direction of travel, or move quickly, people could have been injured.

a row of cars along a highway and a bison about to pass between some of the cars. People are leaning out of their cars for photos, or are right along the roadway

from a Yellowstone National Park report:
“Despite their size and seemingly slow moving habits, bison are surprisingly agile and can be quick to react.”

This photographer might have thought he was far enough away because he had a wall between him and the bison, but bison (1,000 to 2,000 pounds) are capable of hopping quickly over walls:

bison halfway over a wall

Before bison charges has more, including what people were doing before a bison charged them, and injuries they received.

NPS photo Chevy after collision with a bison: NPS photo Chevy with front end damage after collision with a bison.



A marmot 16 inches long plus a 6 1/2 inch tail (can be two feet in length and weigh up to 11 pounds)

and a pika 7–8.4 inches long, 5.3–6.2 ounces (about the size of a guinea pig)

on a trail, for a size comparison:

marmot and pica on trail: marmot and pica on trail



From a distance it can be hard to tell which small animal you see swimming. But each swims differently.

Muskrat swimming:

muskrat in water

Beaver swimming:

beaver in water
River otters undulate through the water. One source says when a beaver swims, only his head shows above the water; muskrats show both their head and part of their back. Another source says that muskrats usually swim with their thin tails “snaking in the water behind them or arched out of the water; you never see a beaver’s tail as it swims.”

Muskrats have been observed swimming underwater for up to 17 minutes, surfacing for three seconds, and then going back underwater for another 10 minutes. Adult muskrats are the size of a football, (their body 16-24 inches long, long narrow tail 7-11 inches),

beavers four times as big. (Beavers reach lengths of three to four feet and weights of up to 40 pounds and can live up to 24 years in the wild.).

Otters are 3 to 4 feet long, minks (rarely seen) half that size.
Otters can remain submerged for several minutes, dive to 55 feet and swim up to a quarter-mile underwater.

Otter “Ears and nostrils close when underwater; whiskers aid in locating prey.”

river otter on land

2 river otters on a grassy bank by water

otter at edge of water

Beavers use their tails as rudders as they swim, to slap the water when they want to warn other beavers they see something dangerous (like you, perhaps) and to help them stand up to reach for and chew branches.

beaver standing upright

Below is a beaver (see the lodge and one of the dams in the background)

beaver lodge Grand Tetons:

beaver nibbling



A golden-mantled ground squirrel 6-9 inches, has stripes that stop before it’s neck, and has a shorter tail than a chipmunk 5 inches to 4 1/2 inches, is a little smaller and has stripes across it’s back and up it’s head.

NPS photo golden-mantled_ground_squirrel: NPS photo golden-mantled ground squirrel sitting up on a tree stub NPS photo chipmunk: chipmunk munching

Larger squirrels include (likely seen in trees) 11–15 inches long Red Squirrel (also known as) Chickaree

squirrel on a tree branch

Unita Ground squirrels, 11–12 inches long, live in burrows they dig. They go into hibernation as early as mid-July and stay in hibernation as long as through March.

2 ground squirrels standing in a meadow



Sightings of bobcat, lynx or mountain lion (cougar) , are not common, but here are their faces for comparison:

nps photo bobcat: nps photo of a bobcatnps photo lynx: nps photo of a lynx nps photo of a mtn lion: nps photo of a mountain lion

and here is a bobcat on the grounds of a Yosemite National Park hotel:

bobcat walking on a pathway

A Yellowstone study found that cougars mostly eat elk, followed by mule deer, bighorn sheep, and pronghorn.

Also a predator, also not commonly seen, the Pine Marten, (NPS notes) 18–26 inches long, is active throughout the year; hunts mostly on the ground. Rests or dens in hollow trees or stumps, in ground burrows or rock piles, in excavations under tree roots.

pine martin on a tree trunk

NPS notes: Ringtailed cats “are known to invade buildings in search of food or to hunt rodents, but they are strictly nocturnal and make every effort to avoid detection. Ringtails weigh only about two pounds and can be up to 32 inches long, adding another 12 or more inches for their fluffy, ringed tail.

Combining their small size and incredible agility, there are few spaces inaccessible to a determined ringtail. Using their semi-retractable claws they can climb most walls and perform cartwheels and other acrobatics to negotiate tight spaces.”

ringtailed cat in rocks



The coyote (25 inches tall, large ones up to 55 pounds) compares in size to a large family dog. One way to tell if what you see from a distance is a dog or a coyote is that when a coyote runs, it generally holds its tail down at an angle, and a dog runs with its tail up. We’ve read that Rocky Mountain coyotes are bigger than the ones we frequently see in Yosemite on our winter trips.

two photos of one coyote in Yellowstone:

Yellowstone coyote at Soda Butte creek winter: Yellowstone coyote winter 2007:

And a coyote walking next to a swimming pool fence in Yosemite National Park:

coyote behind fence railings



A wolf , up to 35″ tall, is much bigger than a coyote or family dog, but it can be hard to tell at a distance, which is where you will most likely see one if at all. Wolves can weight 70-120 pounds, coyotes only 25-40.

Wolves run on the average 5 mph, or up to 35 mph.

Wolves can be coal black, creamy white and everything (gray, tan) in between. Coyotes are gray, tawny, buffy or reddish gray, with some orange on it’s tail and ears.

A red fox barks but rarely howls or sings.It has red fur with white-tipped tail, dark legs; long, slender snout. It has a bushier tail than a coyote. Some are black or silver.

Adult males weigh 11–12 pounds; females weigh average 10 pounds.
Average 43 inches long.

fox sleeping


Below a NPS drawing showing the size comparison of a wolf, coyote and a fox.

wolf, coyote, fox size comparison NPS drawing:

And another National Park Service drawing comparing the size and coloration of a fox (front), coyote (center), and wolf (back), by Michael Warner from a Yellowstone Park webpage

National Park Service drawing of a fox ( front) coyote ( center) and wolf ( back), by Michael Warner from a Yellowstone Park webpage

Many years of maps / charts of wolf pack territories in Grand Teton National park and Yellowstone National park, as well as details about wolves, (inlcluding why wolves howl and how far away you can hear them) are at:
Wolf pack territories in Grand Teton and Yellowstone National Parks and wolf watching tips



The coyote often holds his tail between his legs when running. His nose is more pointed than a wolf.

The coyotes have a narrow, triangular shaped head. A wolf has a more square, blocky head.

A red fox barks, but rarely howls/sings. Wolves and coyotes both sing long howls, but the wolf does not add yips/yaps. Yellowstone park notes that that wolves howl for “intrapack communication, advertising territory, coordinating social activities.” Denali park notes that “Wolves are noted for their distinctive howl, which they use as a form of communication. Biologists do not know all of the reasons why wolves howl, but they may do so before and after a hunt, to sound an alarm, and to locate other members of the pack when separated. Wolves howl more frequently in the evening and early morning, especially during winter breeding and pup rearing. Howling is also one way that packs warn other wolves to stay out of their territory.”

To print a wolf / coyote comparison go to:

and click on wolf versus coyote comparison

Coyote front prints are usually 2 3/4 inches in length or less, some large dog breeds can have prints as big as a wolf, wolves are usually 3 1/2 inches in length not including the claws.

The International Wolf Center tells us that “The biting capacity of a wolf is 1,000 to 1,500 pounds of pressure per square inch… In comparison, a German Shepard has a biting pressure of 750 pounds per square inch. A human has a much lower biting pressure of 300 pounds per square inch.”

First photo below of mollie’s wolfpack in Yellowstone: (in social situations like the first photo, the height the tail is carried generally relates to the social status of that wolf).

mollie's wolfpack NPS Photo by Dan Stahler: five wolves playing in the snow FWS photo gray wolf 130 pixels: head and shoulders of a gray wolf

NPS photo gray wolf pauses along riverbank: gray wolf starting to wade into the water



The main differences between a grizzly and a black bear are:

Two photos below black bears and six of grizzlies are courtesy of NPS:

NPS black bear 220 pxls: NPS Yellowstone black bear and cub: cub, looking towards camera, follows a black bear through a deep grassy area

nps photo grizzly walking on beach: nps photo of a grizzly bear walking on beach by a lake NPS grizzly 220 pxls: nps photo griz number 539: nps photo griz number 539 NPS photo of a grizzly bear identified as by photographer Peaco: NPS photo of a grizzly bear identified as by photographer Peaco NPS grizzly bear cubs 220 pxl: G399 cubs NPS photo by Gary Pollock: two bears just out of hibernation walking on the snow

grizzlies have a dished, or concave face; black bears have a straight facial profile

grizzlies have a large hump of muscle above the shoulders (used for digging and running) This hump is higher / taller than their rump.

grizzly claws (long, for digging) are visible from a distance, black bears claws (short, curved for climbing) are not

grizzlies are bigger (males 300-700 pounds, black bears 210-315 pounds) but an adult male black bear can be bigger than a female griz

coloration in both is so variable, that it isn’t a good way to tell them apart. Black bears are not just black in color, they can be light, medium or dark brown, cinnamon/reddish or blond. Grizzlies can be any of the above, sometimes with silver-tipped guard hairs that give them their grizzled gray / silver appearance.

If you have reason to report a bear sighting, try to notice the color as described above, including any colors of patches on the chest or of girth bands. Be ready to describe the size. A two year old is about 1/2 to 3/4 the size of a female, a yearling about 1/4 to 1/2 the size of a female and the cub of the year is about 1/4 the size of a female. Was there an ear tag, radio collar or paint to identify the bear?

black bears are more likely to stalk a human than grizzlies, although this is quite rare

both can climb trees

grizzly bears can run 40 miles per hour, black bears more likely 30 mph

both hibernate, but sometimes awake during winter and leave their dens (occasionally some black bears in Yosemite, for example, never do hibernate)

both have occasionally become too used to humans and/or human food and have had to be destroyed.

What do Grizzly bears sound like? Griz vocalizations description from Yellowstone Park “Grizzly bears sometimes vocalize when agitated or nervous.. . sounds of huffing, jaw-popping, and low growls are warnings that you’re too close.”

To watch a Grand Teton National park video comparing black bears and griz, go to

and click on Which Bear Did I See?

NPR black bear drawing and tracks: drawing of a black bear and front and hind tracksNPS griz drawing and tracks: drawing of a grizzley and front and hind tracks

The NPS photo of a bear on it’s back shows why bear rear paw prints really do look a lot like footprints of a human:

bottoms of four bear feet


Check out a close encounter with a bear in Yellowstone park, by people who admitted they left their bear spray in the car and will never do so again:


This NPS image of a man spraying bear spray shows the comparison in size of a man and a very large bear:

NPS line drawing of a bear and a man spraying bear spray at it

See links to bear spray videos as well as maps of where grizleys live in the western United States at:
your safety in grizzly bear country

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NPS photo swan landing: a Trumpeter swam with outspread wings landing on a waterway

The difference between a tundra swan and a trumpeter swan (8′ wingspan) is that the tundra swan has a yellow spot near the eye and the trumpeter swan has a thin pink stripe at the base of their upper mandible.

The other huge white birds are pelicans with a huge yellow beak and throat pouch.

two pelicans floating next to each other - photo courtesy of NPS

and here a photo showing the size difference between a Pelican and a seagull:

pelican on a rock, seagull nearby on shore

thin line of various colors of rocks

NPS photos of adult and juvenile Bald Eagles:

The juvenile Bald Eagle above will not get white head feathers until it is about 4 years old.

Osprey also hunt along the water, often in the vicnity of Bald Eagles:

Osprey with wings wide out

and see: Grand Teton National Park birds which includes Bald Eagle, Canada Goose, Golden Eagle, Great Gray Owl, Harlequin Duck, Loon, Magpie, Northern Flicker (woodpecker), Osprey, Pelican, Ouzel, Peregrine Falcon, Raven, Sandhill Crane, Steller’s Jay and Trumpeter Swan, with links to calls from most of them to listen to.

a narrow band of sunset reflected on the water

A note about feathers, courtesy of David Allen Sibley in Sibley’s Birding Basics. Numbers of feathers vary from 940 on a hummingird to 1,500-2,600 on a sparrow to 25,000 on a tundra swan. Feathers “commonly account for 15 % of the bird’s total body weight – about twice as much as it’s skeleton.”



Grand Teton National Park rules say do not approach wildlife, stay 100 yards from bears or wolves and 25 yards from other wildlife including nesting birds. If you have an accidental, surprise or inadvertent closer encounter with wildlife you must remove yourself to those distances.

For your safety while wildlife viewing, stay 25 yards away, at least, for most wildlife, and 100 yards for bears, moose, elk, bison and wolves, whether on foot or in your car.

Keep the animal’s line of travel or escape route clear and move away if wildlife approaches you.

How far away is 100 yards? Picture the length of a football field without the end zones.

25 yards? picture four car lengths or six kayak lengths, or the width of an Olympic-sized pool like ours at the college.

NPS drawing of a human and various animals showing how far away we need to stay from wild animals

NPS drawing of a row of buses depicting the distance people need to stay away from animals

Safe Distances from Wildlife includes reasons to stay away from even friendly seeming animals in parks, and charts and photos to better be able to determine and visualize how far away from wildlife you need to stay to be safe (and obey laws that do have penalties).

Grand Canyon National Park rangers say: “Follow the rule of thumb: if you can cover the entire wild animal with your thumb you’re at a safe distance. This distance is usually 25 yards from most wildlife and 100 yards from large wildlife . . . If you are close enough to take a selfie with an animal, you are too close. ”

Selfies can be great, OR dangerous. The use of cell phones for photography (with or without a selfie stick) has made preventable injury or even death by selfie common. They were only taking a selfie.

Parks Canada warns, along with keeping a proper distance from animals :

“If you spot the following defensive warning signals, pull back even more or leave the area:

Bears make a ‘woofing’ noise, growl and snap their jaws;
Bull elk and moose put their heads down and paw at the ground;
Cow elk flatten their ears, stare directly at you and raise their rump hair.

If you cause an animal to move, you are too close.”

You will really want your own binoculars.

and a telephoto lens for your camera.

Using a drone for your photography is illegal in national parks. NPS notes: “Drones can be extremely noisy, and can impact the natural soundscape. Drones can also impact the wilderness experience for other visitors creating an environment that is not conducive to wilderness travel. The use of drones also interferes with emergency rescue operations and can cause confusion and distraction for rescue personnel and other parties involved in the rescue operation. Additionally, drones can have negative impacts on wildlife nearby the area of use, especially sensitive nesting peregrine falcons on cliff walls.”


See also: animal sign comparisons (how to use tracks and scat to distinguish species) grizzly:grizzly bear scat photo by J Schmidt:

Please do not handle scat. Wolf scat, for example, can transmit tapeworm eggs to humans.

Watch a Grand Teton National park video identifying and comparing animal tracks

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your safety in grizzly bear territory tells you what to do if you see a bear in the distance or a bear charges you and has info about Bear Pepper Sprays and what might happen before a bison charges.

NPS chart of where grizzly bears live in the Greater Yellowstone Ecosystem (the blue outline) in 2008:

nps griz range chart: chart of grizzly range

Recommended reading
Yellowstone Grizzly Bears: Ecology and Conservation of an Icon of Wildness

$39.95 or a free download

Grand Tetons biking has details about rare fatal (often preventable) encounters between bike riders and grizzlys.

This NPS historic photo collection shows people much too close to an elk:

NPS historic photo collection road trip and elk:

For more actual incidents of injuries from animals, usually caused by approaching them too closely, go to: fatal, near fatal or close call incidents/accidents in camping, backpacking, climbing and mountaineering

Look for the BEARS, MOUNTAIN LION, BISON, ELK and MOOSE sections.

For details about our next club trip to Grand Teton National Park, go to: Grand Tetons.

Grand Tetons trip pages index has brief descriptions of most of the pages about this trip.

Grand Tetons kayaking

Grand Tetons sightseeing


Hiking Advice has hot weather hiking advice, hiking logistics and the answer to the question: When is the best time of day to cross a mountain stream?

People often get too close to animals when they are trying to take a selfie.