Managing Yellowstone's Bison Herd

Agreement Ends Eight Years of Difficult
Negotiations, Seven Months of Mediation

The Compromise plan aims to resolve a controversy that led to the killing of more than a thousand Yellowstone bison that migrated out of the park and onto Forest Service and private lands during severe winters in the mid 1990s. Montana officials fear that bison carrying brucellosis could infect cattle and damage the state's livestock industry.

The Bison Management Plan for Yellowstone aims to end the unnecessary killing of buffalo that leave the park in search of winter range. The plan is designed to preserve the largest wild, free-ranging population of bison in the United States while minimizing the risk of transmitting brucellosis disease (between bison and cattle) to protect the economic interest and viability of the livestock industry in Montana.

The NPS signed the joint management plan with the U.S. Depart-ment of Agriculture's Animal and Plant Health Inspection Service and U.S. Forest Service on Dec. 19, 2000. The final plan will keep cattle off land outside the park where bison have grazed until winter is over, the buffalo are back in the park, and there is little danger of bacterial contamination. The pact took more than eight years of negotiation and seven months of mediation between the federal agencies and the State of Montana.

The plan uses an adaptive management approach allowing agencies to gain experience and knowledge before proceeding to the next step. Ongoing research will aid managers by determining the life expectancy of live brucellosis bacteria; the most effective vaccine; and ways of vaccinating buffalo on the hoof.

In cattle, brucellosis causes abortions or the birth of weak caves, and reduces milk production and fertility. Because it is contagious, a single case in a herd can require the destruction of the entire herd. While the new management regime is not intended to be a brucellosis eradication plan, it uses many tools to manage and reduce the potential risk of brucellosis transmission from bison to cattle.

Limited numbers of bison will be allowed on public lands outside the park in winter when cattle are not present. Bison will not be allowed to intermingle with cattle and will be hazed back into the park when the weather typically moderates in the spring (mid-April on the north side and mid-May on the west side). The agencies will capture or remove bison still remaining outside the park that cannot be hazed. Any possible risk to cattle will be further minimized before cattle are allowed to return to public lands by waiting a sufficient amount of time to ensure that the bacteria which cause the disease are no longer alive outside the park.

The agencies will further manage the risk of transmission of brucellosis to cattle by limiting the number of bison outside the park in the north (Reese Creek) and west (West Yellowstone) management areas through intensive monitoring and hazing. When necessary, the agencies will capture, test, and slaughter seropositive bison--those that have tested positive for the brucellosis bacteria. Management activity will be increased as bison move toward the edges of management zones outside the park. The plan also provides that the agencies will maintain a spring bison population of up to 3,000 animals. The agencies also agree to increase nonlethal management measures should severe winter conditions result in a large management removal or natural winter dieoff.

To further reduce the risk of transmission and protect cattle, the agencies will require vaccination if 100 percent of all vaccination-eligible cattle in north and west management zones are not vaccinated within one year. DOA's Animal and Plant Health Inspection Service will pay for all direct vaccination costs. Allowing untested bison outside the park in the north and west boundary management zones will begin after the agencies have had experience with seronegative bison in certain areas outside the park during winter and when the NPS initiates vaccination of bison with an effective vaccine using a safe delivery system in the park.

By adopting the plan, federal agencies and the state of Montana recognize that bison are an essential component of the greater Yellow-stone ecosystem and that the cooperation of several agencies is needed to fully manage the herd. More information on the Joint Management Plan is online at http://www.nps.gov/planning or call 307-344-2159