The New Buffalo Killers

"We were looking at how pretty they were in the snow," says the 70-year-old Hill, who describes himself as an avid hunter. "Then, when the wildlife rangers suddenly shot the bison where they stood, I was so upset I started shaking and damned near cried. I thought, 'Isn't this a fine way to slaughter one of our national symbols?' Now, I think I'll stop hunting."

The slaughter of the bison began as the result of a suit successfully brought by the state of Montana and the Church Universal and Triumphant, a survivalist compound whose New Age leader is Elizabeth Claire Prophet. The Church, which maintains a huge arsenal of explosives and weapons, operates a large cattle ranch adjacent to the park's northern boundary near Gardiner, Mont.

The suit claimed that bison wandering out of Yellowstone might be carrying brucellosis, a disease of bacterial origin, which -- when transmitted to cattle -- can cause spontaneous abortions of the calves. Only a small percentage of the Yellowstone bison carry the bacteria, and to date, there has never been a documented case of brucellosis being transmitted from bison to cattle on the open range.

Even if the Yellowstone bison herds were contaminated with the brucellosis bacteria in large numbers, there would be little chance of them transmitting the disease to nearby cattle, says Dr. Jasper Carlton, director of the Biodiversity Legal Foundation, in Boulder, Colo. That's because the disease is only transmitted through contact with infected, aborted fetuses or contaminated birthing fluids or tissue. Bison rarely experience abortion. In Yellowstone in the past 75 years, there have been only four bison abortions, and it is not known if these were the result of brucellosis.

"The real absurdity is that when the bison, following their ancient migratory routes, return to Yellowstone in the spring to give birth, there are no cattle around to be infected," says Steve Kelly, director of the Montana Ecosystem Defense Council. "Even if you buy the state of Montana's brucellosis threat argument, the rangers should at worst only be killing pregnant female bison. They are killing every bison that wanders out of the park."

It is one of the bitter ironies of this story that brucellosis is an exotic disease, passed on to bison in the 19th century by European cattle. Moreover, the brucellosis bacterium is now carried by most of the mammals in the Northern Rockies, from elk to field mice.

The motivation of the state of Montana is to assert increasing control over the management of Yellowstone, particularly its wildlife and its recreational activities. As part of its ideological battle with the federal park, Montana, backed by timber, mining and ranching interests, claims the right to kill not only bison but also any grizzly bear or gray wolf that strays beyond Yellowstone's borders.

The reason male bison and calves are being killed even though they pose no threat of transmitting the disease is that the Church Universal and Triumphant claimed in its suit that the wandering bison were knocking down its fences. Yellowstone Park sits on a high plateau, and the natural migratory pattern is for the elk and bison to descend to lower elevations -- such as that now occupied by the Church's ranch -- in the hard winter months, when the park is buried under as much as 20 feet of snow.

The bison observed by Hill and Koski had followed a new trail out of the park: a groomed path for the hordes of snowmobilers who have invaded Yellowstone in recent years. The reason the bison death count is so high -- the original Park Service estimate had been that perhaps 200 animals might be killed -- is because the packed snowmobile trails have allowed the bison to move quickly through what would otherwise be impenetrably deep snow.

The Bison Action Project, based in Missoula, Mont., is coordinating protests. Let the Montana State Department of Tourism (406-444-3111) know your feelings and maybe where you won't be going this summer.