In winter a portion of the Yellowstone buffalo population migrates across Park boundaries to traditional winter range following the Yellowstone River valley, a trek that once reached beyond present-day Livingston, Montana - a 55 mile journey from the Park's gateway Arches in Gardiner, Montana. Buffalo also move from geothermal habitats into the Madison River corridor in search of wintering range and spring calving grounds. Nomadic migrations by wild buffalo in Yellowstone originally stretched across the Gallatin River valley, and into the Snake River Plain.
Today, under the banner of "disease risk management" and the so-called Interagency Bison Management Plan, Montana Dept. of Livestock inspectors and National Park Service Rangers intercept and harass buffalo off their winter range and spring calving grounds and capture wild buffalo in a slaughter program done in partnership with Yellowstone National Park that has destroyed over 3,200 wild buffalo in the last decade.
Arbitrary boundaries are drawn and America's last buffalo are destroyed for stepping across a line into Montana, Idaho and Wyoming.
The undocumented claim by the state of Montana and Yellowstone National Park is grazing cattle in the buffalo's range are at risk of contracting brucellosis - a disease introduced by exotic cattle to native elk and buffalo before 1917. Buffalo calves captured from the wild were "mothered with domestic bovine cows" and pastured with cattle that were brought into Yellowstone to feed Park tourists.
Recent investigations of brucellosis transmission to cattle in the Yellowstone ecosystem indicate that elk are the suspect source of infections in Montana, Wyoming and Idaho.
There has never been a documented case of a wild buffalo transmitting brucellosis to livestock.
Meagher, Margaret M. 1973. The Bison of Yellowstone National Park. Scientific Monograph Series Number One. National Park Service, Washington, D.C. 161 pp.
Meagher, M. and Margaret E. Meyer. 1994. On the Origin of Brucellosis in Bison of Yellowstone National Park: A Review. Conservation Biology 8(3): 645-653.
Beja-Pereira, Albano, Betsy Bricker, Shanyuan Chen, Claudia Almendra, P. J. White, and Gordon Luikart. 2009. DNA Genotyping Suggests that Recent Brucellosis Outbreaks in the Greater Yellowstone Area Originated from Elk. Journal of Wildlife Diseases 45(4): 1174-1177.