News Release

View Bison from Long Distance to Protect Their Health and Yours

Date: May 4, 2016
Contact: Kristy Burnett, 970-267-7205

FORT COLLINS, COLO. – Visitors come from around the globe to view the bison ranging freely in Yellowstone National Park. However, when people get too close to bison, problems can arise. In 2015, five people were injured while approaching bison in the park. This follows two years of no reported injuries from bison in Yellowstone. At the Epidemic Intelligence Service conference May 2–6, 2016, Cara Cherry of the National Park Service (NPS) presents research about human injuries due to encounters with bison in Yellowstone. Nearly half of the 25 injuries from 2000–2015 occurred when people approached bison too closely while taking photographs of them.

Cherry analyzed the human injuries resulting from bison encounters from 2000–2015. During this time, bison injured 25 individuals, with the 5 injured people in 2015 being the greatest number in one year. Researchers classified these injuries as butting (hitting person with head), goring (puncturing body with horn), or tossing (throwing person into the air). Goring is the most severe injury. Of the 25 hurt individuals, 22 required medical treatment, and 12 of them were hospitalized. There were no deaths.

Most of the injuries caused by bison encounters are preventable. The majority (80%) of people hurt by bison in Yellowstone actively approached the bison leading up to the event despite the regulations to stay 25 yards away to protect both people and wildlife. The NPS is conducting additional investigation to determine if other messaging is needed. The research serves as a good reminder to respect wildlife and provide them with the space they need to keep both people and animals healthy.

To protect both humans and wildlife, Yellowstone prohibits approaching within 100 yards of bears or wolves and within 25 yards of any other wildlife, including bison. Despite this rule, all of the people in the study hurt by bison were within 6.5 yards of the animal leading up to the incident. Bison are the largest land-dwelling mammal in North America, so visitors may not expect them to run up to 35 miles per hour or jump over objects 5 feet tall.

Injuries from bison are not a new public health concern. From 1980–1999, bison caused more injuries to pedestrian visitors than any other animal in Yellowstone. Then, from 1983–1985, 33 visitors to Yellowstone sustained injuries from bison. This high number prompted a major public outreach campaign; graphic posters and brochures at entrance stations and campgrounds now warn visitors of the dangers of approaching wildlife. As a result of the awareness effort, the number of injuries fell to an average of one per year from 2000-2015.

Recovering bison in Yellowstone is a great conservation success story. In 1900, bison were nearly extirpated (extinction in a local area) across North America, leaving only a small number of animals in central Yellowstone. Thanks to protection and stewardship, the number of bison has increased to approximately 7,500 in nine different NPS units, according to a 2014 Department of the Interior report.

For more information about this report on human injuries from bison, contact Cara Cherry. Visit this website to learn more about the National Park Service’s Wildlife Health Branch.