Buffalo Roam at Their Own Peril

As spring advanced on the rolling hills of the northern range, park workers on horseback herded more than 200 bison into corrals near the massive stone arch that marks Yellowstone’s original entrance.

While protesters recorded the roundup on video and law enforcement officials followed in squad cars with flashing lights, 61 bulls, 116 cows and 54 10-month-old calves were loaded into livestock trailers, trucked across the Yellowstone River past the motels and gas stations of the little tourist town of Gardiner, and hauled to slaughterhouses.

The National Park Service was executing its own icon, the brawny beast it helped save from oblivion, the one that is emblazoned on Park Service uniform badges.

At the same time that Yellowstone’s buffalo herd is celebrated for its wildness and genetic purity, it is maligned by cattle ranchers as a disease-carrying threat to livestock grazing next to the park.

Today the bison are free to roam just as their ancestors did, as long as they don’t act too wild and wander over the park boundary into Montana. Then they can be driven back into the park and carted off to slaughter, lest they infect cattle with brucellosis -- a disease the buffalo probably got originally from livestock.

The story of the largest continuously free-ranging bison herd in the U.S. is also about the limits of wildness in America’s first great wilderness park. Nature is supposed to reign supreme in Yellowstone’s 2.2 million acres, determining what lives and what dies. Yet when it comes to Yellowstone’s few thousand bison, nature’s rules have been subordinated to those of the cattle industry.

The New West’s appetite for wildness is likely to be further tested as the federal government moves to ease or drop endangered-species protections for two of Yellowstone’s other fabled species: the gray wolf and grizzly bear. Will they be allowed to truly roam free, or will they be safe only within the federal parks?

“Where can these large carnivores reside? What is socially tolerable and economically feasible?” mused Nina Fascione, vice president of species conservation for Defenders of Wildlife. “I don’t think anybody knows. We’re new at this. We just know how to kill them off.”

After a 60-year battle with brucellosis, cattle herds in all but two states, Texas and Missouri, have been officially declared free of the disease, which causes cows to abort, decreases milk production and induces sterility. The U.S. Department of Agriculture expects brucellosis to be banished soon from livestock in those two states as well, which will make the Yellowstone area’s bison and elk the nation’s last known carriers of the disease.

The government wants it gone from them too.

“As long as it’s endemic in wildlife in the Greater Yellowstone Area, it does pose a threat to cattle in surrounding states,” said Jack Rhyan, senior staff veterinarian for the USDA’s National Center for Animal Health Programs.

Infected cattle herds are destroyed, and if a state loses its brucellosis-free status, stockmen have to test livestock before shipping it out of state.

The disease was found in Yellowstone bison in 1917. It has had little effect on the herd and, for the first half of the last century, the park infection was not much of an issue.

But as the government campaign against brucellosis mounted and the size of the Yellowstone herd grew after the park stopped culling buffalo in the late 1960s, so did pressure on the Park Service to do something.

Montana has been so riled about the brucellosis threat that, over the years, it has approved a hunting season for bison roaming outside the park, sued the federal government and declared Yellowstone buffalo “a species in need of disease management.”

The hunting season was repealed in 1991 after turning into a public relations nightmare, but this spring the state legislature voted to reinstate it in a bill now awaiting the governor’s signature.

The brucellosis controversy reached a boiling point during the winter of 1996-97, when bison headed out of the park’s deep snow and ice en masse in search of food and more than 1,000 were shot by the Montana Department of Livestock and the Park Service. A few hundred more died of starvation, thinning the herd from 3,500 to 2,000 animals in months. The killings made headlines across the country and prompted a public outcry.

In 2000, the park adopted a compromise in the form of a bison plan that recognizes the herd as wild and free-roaming but, paradoxically, limits its size and movement out of the park.

That is why the Park Service says it rounded up 231 of the large animals this spring and shipped them off to slaughter like so many feed-lot cattle. The herd was approaching 4,000 animals, exceeding the plan’s target size of 3,000, a figure above which bison movement from Yellowstone is likely to increase, according to a National Academy of Sciences report.

As he stood on a wooden plank above the pens a few weeks after the trapping, park wildlife biologist Rick Wallen conceded that it was “difficult to swallow.” But the plan eventually will allow a limited number of buffalo to cross the park boundary into adjacent cattle-free zones without being shot.

“Is it a plan that would be the first choice of everyone? No,” said Wayne Brewster, deputy director of the Yellowstone Center for Resources. “Is it a plan that everyone can live with for a while? It seems to be. And it will conserve bison and manage the risk” of brucellosis infection.

The risk is small -- so small that there is no documented case of brucellosis transmission from wild, free-ranging buffalo to domestic cattle. There have been a handful of cases in the Yellowstone area in which wildlife is suspected of infecting cattle herds, but in the majority of those cases, elk are believed to be the culprit.

Yet elk are allowed to wander in and out of the park with impunity. State and federal officials explain the discrepancy variously: There are far too many elk to control in the same manner as buffalo, and elk have a lower brucellosis infection rate than bison. Also, because elk hunting is big business, the game animals have a powerful political constituency that bison lack.

Dan Flores, a professor of Western history at the University of Montana, suggests yet another, more amorphous reason. In a region not that far removed from the frontier, bison can represent something ominous: the untamed. “I think it has to have a great deal to do with the symbolic role of buffalo in history,” Flores said. “Everybody loves having elk around. But because of the association of bison with a land-use policy linked with Indians, wilderness and not much control of nature ... the animal symbolizes some sort of reversion for a lot of people in the West, especially for stockmen.”

Yellowstone’s bison herd barely survived the 19th century. Poaching and hunting continued even after the park was established in 1872, and by 1901, only 23 buffalo were counted in the park. Congress authorized $15,000 to rebuild the herd, and the following year, the park bought 21 captive buffalo from ranches in Montana and Texas.

Though native and imported animals later intermingled, some of the Yellowstone herd has always been wild. It is one of a few free-roaming herds in the country. That has helped it retain a valuable genetic pedigree.

Though U.S. buffalo numbers have climbed to more than 300,000 from near extinction at the end of the 1800s, most herds are captive, privately owned, and carry the genetic legacy of early ranching efforts to interbreed buffalo with domestic cows to produce bigger and better beef cattle. In other words, they are not completely buffalo.

But the federal herds are for the most part genetically pure, according to associate professor James Derr of the Texas A&M; College of Veterinary Medicine, who is doing genetic research on the 15,000 bison in federal parks and preserves. He has so far tested more than 500 Yellowstone buffalo and found no evidence of cattle genes. What he has discovered is an impressive genetic richness.

Conservationists argue that the brucellosis issue could be easily defused if cattle grazing were stopped around Gardiner and West Yellowstone, the two spots bison use to exit the park.

“I’ve worked on environmental issues for 25 years and I’ve never seen a simpler issue: Move the cows,” said Will Patrick, coordinator of the Greater Yellowstone Wildlife Alliance.

The Gallatin National Forest, which borders Yellowstone on the north and west and leases grazing rights to ranchers, says it is looking for alternative sites for the cattle. But that would still leave some private grazing in the area. The park is also about to embark on a new brucellosis vaccination program for the bison. Yet no one knows how well it will work. And no one has figured out how to make a wild, nomadic animal observe a boundary that it instinctively wants to trample.

“We’re trying to confine bison in a high-elevation area where hundreds of years ago they would have hardly been in the winter,” said Dan Bjornlie, a trophy game biologist with the Wyoming Game and Fish Department who has studied the Yellowstone herd.

“Eventually, they’re going to push against whatever boundary line you draw,” Bjornlie added.