A Brief History

Once numbering in the tens of millions, American bison were nearly driven to extinction in the 19th century. By 1902, only around two dozen remained in Yellowstone. Thanks to conservation efforts and protective legislation, the population has since rebounded. Today, 4,000–5,000 bison roam the park freely—descendants of the few that survived, and one of the only genetically pure, continuously wild herds in North America.

Behavior and Social Structure

Bison are social animals. Females and calves travel in large herds, while males often form small bachelor groups or roam solo outside the mating season. Despite their bulk, bison are surprisingly agile and they can run up to 35 mph, pivot quickly in mid-air, and leap over fences or obstacles up to 6 feet high.

These skills help them navigate Yellowstone’s diverse and often rugged terrain. Their massive heads also serve as snowplows in winter, sweeping away snow to reveal the grasses underneath.

The Rut: Summer's Thunder

Late July through August marks the bison rut, when the valleys of Yellowstone echo with bellowing bulls, dust clouds from wallowing, and thunderous clashes. Bulls compete for females by posturing, grunting, and engaging in full-body battles. It's one of the most dramatic wildlife events in North America.

Fall: Building Strength

As mating season fades, bison herds shift their focus to feeding. Bulls drift apart from the main groups. Autumn’s cooler temperatures and golden grasses make this a peaceful time to observe them. You will often see large herds grazing in Lamar and Hayden Valleys. The calm before winter sets in offers excellent photography opportunities, especially during early morning fog.

Winter: Survival Mode

Winter in Yellowstone brings a quiet beauty that few get to witness. Blanketed in snow, the park offers an incredible backdrop for photographing bison in their thick winter coats. Their woolly fur protects them from the cold as they sweep away snow with their massive heads to reach the grasses below. Steam rises around them in geothermal areas like the Firehole River and Norris Geyser Basin, creating dramatic, almost otherworldly scenes.

With fewer visitors in the park, winter provides a rare chance to photograph bison in peaceful, snow-covered landscapes, often with just the sound of crunching snow and distant geysers in the background.

Spring: New Life on the Landscape

From late April through May, bright orange “red dog” calves begin to appear. These young bison are energetic and alert within hours of birth, often seen bounding alongside their mothers. The herd spreads out across the landscape as they seek fresh grazing areas, and females become especially protective during this time.

Spring is one of the best times to witness the full family dynamics of a bison herd in action, from nurturing behavior between cows and calves to the herd’s constant movement and communication. It’s a lively, engaging season that offers a deeper look into the social fabric of bison life.

Give Bison Space

Bison may appear slow or calm, but they are wild animals capable of sudden and aggressive behavior, and they injure more visitors in Yellowstone than any other species. They can run up to 35 mph, pivot quickly, and charge with little warning. Signs of agitation include head bobbing, pawing the ground, snorting, or bellowing. If you see any of these, back away immediately.

Always stay at least 25 yards (23 meters) away. For closer views, use a long telephoto lens or binoculars. Respecting their space not only keeps you safe, it ensures these animals remain undisturbed in their natural behavior.

A Symbol of the Wild

Watching Yellowstone’s bison through the seasons offers a rare chance to witness raw nature in motion. From newborn calves to rutting bulls and snow-dusted herds weathering winter storms, these animals embody endurance, wildness, and resilience.

Whether you visit in spring, summer, fall, or winter, the bison of Yellowstone will leave a lasting impression.

We offer guided photography tours to Yellowstone in fall and winter, when bison are especially photogenic, framed by golden foliage or blanketed in snow. These seasons offer fewer crowds, dramatic light, and unforgettable wildlife moments. Check our photo tours and workshop pages for more information.