• A bull elk bugles in Yellowstone National Park

    Yellowstone

    National Park ID,MT,WY

Yellowstone Bison

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Yellowstone is the only place in the United States where bison (Bison bison) have lived continuously since prehistoric times. Yellowstone bison are exceptional because they comprise the nation’s largest bison population on public land and are among the few bison herds that have not been hybridized through interbreeding with cattle. Unlike most other herds, this population has thousands of individuals that are allowed to roam relatively freely over the expansive landscape of Yellowstone National Park and some nearby areas of Montana. They also exhibit wild behavior like their ancient 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. However, some Yellowstone bison are infected with brucellosis, a livestock disease that can be transmitted to wild bison and elk as well as cattle through contact with infected fetal tissue. To prevent conflicts with ranching and other activities outside the park, the National Park Service works with other federal, state, and tribal agencies to manage and develop policies for bison access to winter range there. Conservation of wild bison is one of the most heated and complex of Yellowstone's resource issues. All of the interested parties bring their own wide-ranging values and objectives to the debate. Learn more...

Quick Facts on Bison in Yellowstone

  • Population estimated at 4,600 in two breeding herds, northern and central.
  • Male (bull) weighs up to 2,000 pounds (900 kg), female (cow) weighs up to 1,000 pounds (500 kg).
  • May live 12–15 years, a few live as long as 20 years.
  • Feed primarily on grasses and sedges.
  • Mate in late July through August; give birth to one calf in late April or May.
  • Can be aggressive, are agile, and can run up to 35 miles per hour (55 kph).
 

Additional Resources

Bison Management
Bison References

Did You Know?

Bison in Yellowstone.

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.