Oldest and Largest: The Bison of Yellowstone

There is perhaps nothing more representative of the Great Plains of North America than the image of a herd of bison thundering across a vast expanse of grassland.

Millions of these massive creatures, known so well for their enormous heads and long shaggy brown coats, historically ranged across the continent from the Appalachians to the Rockies, and from the Gulf Coast to Alaska. By 1889, due in large part to market hunting, numbers were reduced to just over 1,000. Today bison numbers have rebounded, mostly in places like national parks and wildlife conservation areas.

Today, there are estimated to be roughly 500,000 bison living across North America. 

Yellowstone National Park, perhaps best known for its geothermal features like Old Faithful and Mammoth Hot Springs, is one place where these animals have always done well. The Park preserves the most important bison herd in the United States because it is the only place where bison have lived continuously since prehistoric times. The herd here, estimated in 2015 to be at 4,900, is the oldest and largest public bison herd in the United States. Believe it or not, Bison are fast. As in they can run up to 35 miles-per-hour fast! They’re also relatively agile and strong swimmers. Do you have a 5 ft high fence? They can leap it! Their vision and hearing are excellent as well as their sense of smell. While Bison can be active at night, they are much more active during the day and at dusk. Females tend to be in charge of the herds, which can fluctuate in size between winter group sizes of about 20, to summer group sizes of around 200 with the maximum herd sizes reaching 1,000 during the rut, or breeding season, which is July and August. 

Bison are ruminants with a multiple-chambered stomach that includes microorganisms such as bacteria and protozoa to enable them to effectively digest plant material. They alternate between eating and ruminating, which is regurgitating partially digested food and chewing it again, to allow microorganisms to further break down plant material into volatile fatty acids and other compounds. Their large digestive tract allows them to digest lower quality foods with greater efficiency than other ungulates such as cattle, deer, or elk.

Bison have two large predators to be concerned with. Wolves and Grizzly can, and will, attack to which Bison defend themselves as a group, making them more difficult to kill than animals like elk who’s strategy are to run away. Yellowstone bison are exceptional. Unlike most other herds this population has thousands of individuals that are allowed to roam relatively freely over the enormous expanse of protected habitat. This herd exhibits wild behavior similar to their ancestors, congregating during the breeding season to compete for mates as well as migration and exploration that result in the use of new habitat areas. These behaviors have enabled the successful restoration of a population that was on the brink of extinction just over a century ago.

We have all seen images of the great Bison. Whether in films (think Dances With Wolves) or in photographs, magazines, or galleries, these massive beasts are striking and are highly sought after by wildlife photographers, like us!  

Bison are a big attraction for Backcountry Journeys guests and photography tours like our Yellowstone Wildlife Safari, Spring Comes to Yellowstone & Grand TetonYellowstone & Grand Teton in Autumn, and Yellowstone in Winter will get you and your camera in the front row for all the action! In fact, bison are a HUGE attraction with grown males weighing in at up to 2,000 lbs. These big guys are the largest land-dwelling mammal in North America.

Yellowstone is, without doubt, one of the most diverse and unique natural habitats in the world and is the largest single intact ecosystem in the United States. Wildlife like the great Bison thrives across the Park’s vastness of the protected natural landscape. It is here in the American Serengeti that the oldest and largest roam plentiful and free, just as they once did across the entire continent of North America.


Kenton Krueger








Kenton Krueger has spent the past several years guiding backpackers, hikers, and photographers into the wild places of the American West such as Grand Canyon, Yellowstone, Yosemite, Glacier, Katmai, Zion, Bryce Canyon, Arches, Canyonlands National Parks, as well as internationally in Costa Rica & Brazil. In addition to backpacking and camping, his adventures include rock climbing, exploring the slot canyons of southern Utah, mountain biking, and bagging 14ers in Colorado’s San Juan Mountain Mountain Range. Kenton is a trail runner, former pilot, and spent roughly five years writing and photographing for the award-winning Omaha World-Herald newspaper, out of his hometown, Omaha, Nebraska. Kenton looks forward to utilizing his years of trip leading and guiding experience, combined with his passion and experience behind the lens, to provide memorable and unforgettable experiences at the wild places we will visit together.

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