Bison leaving Stephens Creek, headed to Fort Peck as part of the Bison Conservation Transfer Program/NPS, Jacob W. Frank

Another truckload of bison from Yellowstone National Park has been sent to the Fort Peck Indian Reservation in Montana, where they will complete a quarantine period to ensure they don't carry brucellosis.

The 28 bison were shipped Wednesday to the Assiniboine and Sioux Tribes. All the bison completed Phases I & II of the brucellosis quarantine protocol at Yellowstone and the Animal and Plant Health Inspection Service facilities and will finish assurance testing (Phase III) at Fort Peck.

The National Park Service, APHIS, State of Montana, and Fort Peck Assiniboine and Sioux Tribes started the Bison Conservation Transfer Program to identify brucellosis-free bison and transfer them to new areas as an alternative to sending them to slaughter. The program has led to the largest transfer of live Yellowstone bison among Native American Tribes in history. Since 2019, 182 bison have gone to the Assiniboine and Sioux Tribes of the Fort Peck Indian Reservation. Of those, 82 animals were transferred to the InterTribal Buffalo Council, which distributed them to 18 tribes in 10 states.

Brucella abortus, a bacterium thought to have reached the country from European livestock, can cause spontaneous abortions or stillbirths in bison and cattle. Until 2010, if two or more herds in a state contracted the disease, or if a single herd detected to carry the disease was not sent to slaughter, all herds in that state were blacklisted from markets. Today that blacklisting applies only to the affected herd.

In Yellowstone, upwards of 60 percent of bison are thought to have been exposed to brucellosis; the park’s herds are judged to be “chronically infested” with the disease. But while bison long have been viewed as the key players in carrying the disease to livestock, that’s not the case at all.

“In tracing the genetic lineage of Brucella across the ecosystem and among species, elk are now recognized as a primary host for brucellosis and have been the major transmitter of B. abortus to cattle,” the National Academy of Sciences concluded in a 2017 paper.

“All recent cases of brucellosis in GYA cattle are traceable genetically and epidemiologically to transmission from elk, not bison,” the paper pointed out.

The bison transferred this week were captured at Stephens Creek in the northwest corner of Yellowstone back in March 2020. Twenty males completed quarantine in the park and a small family group of eight (1 male, 4 females, 3 calves) completed quarantine in the nearby APHIS-leased facility at Corwin Springs. Currently, 67 animals are still in the Bison Conservation Transfer Program and the park and APHIS intend to enter 80-120 new animals into the program this winter. 

To expand the program, Yellowstone has partnered with Yellowstone Forever and the Greater Yellowstone Coalition to increase the capacity of the facility within the park from holding 80 animals to 200 animals. Improvements will be completed this winter. These improvements and continued coordination with APHIS will result in transferring about 100 animals a year to Tribal Nations as an alternative to slaughter.