Bison are the largest land animal in North America and the one animal you’re almost guaranteed to see in the park, regardless of season. They once roamed the prairies by the millions, but wanton slaughter in the late 1880s reduced their numbers to 24 — all in Yellowstone National Park. Prolific breeders, the bison have restored their populations to several thousand. But they remain the only wild animal in the country that is largely confined to the borders of a national park. There are two separate bison herds in Yellowstone National Park— one in the northern range and another that frequents Hayden Valley.  Grand Teton National Park also has a bison herd.

• The Yellowstone National Park population is the only genetically pure and continuously wild bison herd in the world.
• There are 200,000 domesticated bison on ranches in the U.S, the source of bison meat found in stores and restaurants.
• Though docile, bison can run up to 35 mph when provoked.
• More Yellowstone National Park visitors are injured by bison than any other animal.

Best viewing: Lamar Valley, Hayden Valley, Yellowstone’s North Entrance

Photo credit: Len Trout