Bison Conservation Transfer Program

A bison leaping out of a trailer
Release of 55 Yellowstone bison on the Fort Peck Indian Reservation.

Due to high rates of survival and reproduction, the bison population is currently increasing by 10% to 17% per year. Predation by wolves and bears has little effect on bison numbers. Until there is more tolerance for bison outside Yellowstone, the population will be controlled by hunting outside the park and capture near the park boundary. Captured bison are transferred to American Indian tribes for slaughter and distribution of meat and hides to their members. However, many people are uncomfortable with the practice of capturing bison and shipping them to slaughter to reduce numbers. Thus, the National Park Service initiated the Bison Conservation Transfer Program to identify bison that don't have brucellosis and transfer them to new areas as an alternative to sending them to slaughter. The State of Montana, Animal and Plant Health Inspection Service, Yellowstone National Park, and Fort Peck Tribes spent several years figuring out how and where to implement the program, which is now underway. Since 2019, 154 bison have been transferred to the Fort Peck Tribes. Of those, 82 were transferred to 17 other tribes across the country. Another 110 animals are in the program right now and will be transferred to the Fort Peck Tribes in the coming years.

Relocating Bison

During August 19-23, 2019, Yellowstone National Park moved 55 bison to the Fort Peck Indian Reservation in northeastern Montana. It was the first direct relocation of bison to a new home as an alternative to slaughter and was the culmination of eight years of compromise between the federal government, State of Montana, and Fort Peck Tribes. Those bison had been held in a rehoming facility in the park for the previous 17 months and undergone rigorous testing to show they did not have a disease called brucellosis.

Up until 2020, rehoming bison has not been possible because of brucellosis. Some Yellowstone bison are infected with this disease, which affects bison, elk, and domestic cows. It reduces production in livestock and marginally affects bison health. To help stop the spread, Montana law prohibits the live transfer of Yellowstone bison to new areas unless they are first certified as brucellosis-free. Brucellosis-causing bacteria evade the immune system in early stages, such that an infected bison may not test positive for the first several months or longer after contracting the disease. Proving a bison does not have brucellosis takes much more than testing them one time when animals are rounded up. It takes placing them in fenced quarantine pastures with similarly aged animals and holding and repeatedly testing them for one to three years. During 2005-2012, APHIS developed and verified procedures for identifying Yellowstone bison that don't have brucellosis. Afterward, Yellowstone National Park, the Fort Peck Tribes, the State of Montana, and APHIS agreed on how to implement the procedures.

Yellowstone continues to roundup hundreds of bison that migrate out of the park each winter, but beginning in 2018, some captured bison are moved into the conservation and transfer program. Once in the program, animals are moved between facilities to undergo different testing phases. The first two phases of testing are completed in facilities in Yellowstone or on private lands leased by APHIS near the northern park boundary. APHIS and State of Montana animal health officials certify bison as brucellosis-free at the completion of Phase 2. Certification allows their transfer across the State of Montana to the Fort Peck Indian Reservation. Bison complete Phase 3 at the Fort Peck Indian Reservation. After Phase 3, the Fort Peck Tribes transfer some bison to the InterTribal Buffalo Council, who distribute them to member tribes throughout North America.

A graphic showing the different stages of bison testing
The phases of selecting, testing, and transferring bison.
A map of North America with lines to indicate where bison have been transferred
Transfers of Yellowstone bison to start new or augment existing herds.

The Fort Peck Tribes started their Yellowstone herd by accepting bison that completed the 2005-2012 pilot study. In 2012, 63 animals were transferred, and 138 animals were transferred in 2014. Today, the Fort Peck Tribes conserve 300-400 bison across more than 18,000 acres on their lands. Yellowstone and APHIS transferred 93 bison to the Fort Peck Tribes in 2019, 11 in 2020, and 50 so far in 2021.

The conservation and transfer program has led to the largest transfer of Yellowstone bison among Native American Tribes in history. The Fort Peck Tribes recently transferred 40 of the animals received in 2019 to the InterTribal Buffalo Council, who distributed them to 16 member tribes across nine states. There are 110 more bison being held in the Yellowstone National Park and APHIS facilities undergoing testing, which could qualify for transfer to the Fort Peck Tribes within the next 1-2 years.


Expanding the Bison Conservation Transfer Program

Currently, there is not enough space for all the bison that qualify for the program. The first two phases of testing require that animals are held within state and federally approved quarantine facilities. There are currently two such facilities, one inside Yellowstone National Park and the other on private land leased by APHIS near the northern park boundary. Yellowstone wants to more than double the capacity of its facility. Currently, the facility consists of a 10-acre pen that holds about 30 animals, and a 20-acre pen that holds about 70 animals. We want to divide the 20-acre pen in half and construct at least two additional pens. Each pen requires double fencing to prevent nose-to-nose contact. The water infrastructure must be reconstructed to provide the amount needed for the larger number of animals. We also need to construct a low-stress handling corral to support the increased testing that comes with more animals.

These improvements will go a long way toward eliminating sending program-eligible animals to slaughter. Right now, about 75% of program-eligible animals are sent to slaughter. These improvements will reduce that number to 35%. We will be able to increase capacity of the program from entering 100 animals to entering 250 animals over three-year intervals and increase the number of bison transferred to new areas from 30 to 80 animals per year. Yellowstone Forever, Greater Yellowstone Coalition, Defenders of Wildlife, and other nongovernmental organizations want to work with the National Park Service and Fort Peck tribes to help expand the program. They are supporting tribal engagement, transporting animals, improving public awareness, and helping to increase program capacity.


Conserving large herds is one of the greatest wildlife restoration challenges of our generation. Yellowstone bison remain the model of restoring large, wild herds. There is not another bison population who, by their sheer numbers, restore lost ecosystem processes across large landscapes. The large herds provide unparalleled reconnection of people to the long-lost herds that once roamed the continent, but the benefits of large numbers come with the challenge of managing large numbers. The Bison Conservation Transfer Program cannot solve the dilemma of needing to remove large numbers of bison from the population each year, but it may go a long way to making conserving large herds more doable.

Yellowstone bison have some of the most valuable genetics for long-term conservation of the species and can only be augmented into other herds through the conservation and transfer program. Bison completing the program are transferred to Native American tribes to help restore their lost cultures and ways of life. Yellowstone bison may mean more to them than most other people. Entire cultures are intertwined with bison and the great herds that once roamed North America.

"I longed for that time when Tatanka Sicun, Buffalo Spirit as ancestor, mingled with mine...
... then yesterday it came... ... it came in the form of trucks and trailers carrying sacred beings
into the realm of our higher plains..." LOIS RED ELK, member, Fort Peck Sioux

Many tribes see Yellowstone bison as uniquely linked to their ancestral descendants because they were never completely extirpated from the park. To many tribal members, returning bison to tribal lands goes well beyond finding an alternative to slaughter. It is about restoring a part of themselves that is missing. Negotiating more tolerance for bison outside Yellowstone is going to take a long time. In fact, we may never find enough tolerance outside the park to eliminate the need for some population control. In the interim, identifying brucellosis-free bison and moving them to new homes may be part of the solution to giving bison some more room to roam. It is the beginning of returning Yellowstone bison to the lands where they once roamed.


Last updated: October 20, 2021

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