View of Brucella melitensis colonies under a microscope.Larry Stauffer/MediaforMedical/Getty Images
In the 1930s, the federal government launched a decades-long, multibillion-dollar campaign to eradicate brucellosis. It succeeded, officials say, everywhere but Yellowstone.
By the 1960s, the Yellowstone bison population had grown back to more than 1,000. New ecologists, some of whom were instrumental in the passage of the 1969 Wilderness Act, counseled that it is the duty of national parks to allow native animals to roam free, not fenced in or fed like livestock. Park officials agreed, and the bison ranch closed for good.
Yellowstone bison became prized for the strength of their genes, their heritage and their popularity with millions of visitors.
“They’re a unique resource,” said James A. Bailey, who taught wildlife biology at Colorado State University and wrote a book about bison. “And an irreplaceable one.”
But the park’s break from ranching enraged the cattle industry. Starting in the 1970s, livestock associations around Yellowstone passed resolutions demanding that the National Park Service eradicate brucellosis, something the ranchers said was possible only by capturing and testing bison like domestic cattle, and killing any that had the antibodies.
When Yellowstone’s bison count topped a few thousand in the 1980s, some reclaimed ancient migration routes, tromped along river channels and crossed the border into the state of Montana. There they were gunned down. Livestock officials said this was necessary because of the possible presence of brucellosis.
“I have seen grown men and families fallen because of brucellosis,” Jim Hagenbarth, 65, who ranches in Montana and Idaho, said of the financial burden. “This is a tough disease.”
A brucellosis outbreak in a domestic herd triggers tests from the Animal and Plant Health Inspection Service, a part of the U.S. Department of Agriculture. The cost can cripple ranchers, officials say, because in the past entire cattle herds were slaughtered when an animal tested positive for the disease. Whatever the immediate costs, the threat to American beef markets is such that brucellosis “must be contained,” said Department of Agriculture spokeswoman Joelle R. Hayden. The last outbreak was in 2012 and was traced to an elk.
Even when an outbreak is stanched, livestock officials say, their industry is still hurt by stigma long afterward.
“Brucellosis affects the marketability of cattle coming out of Montana,” said Errol Rice, executive vice president of the Montana Stockgrowers Association.
But in 2010, in an effort to balance conflicting interests, the federal government set new testing rules for the area around Yellowstone to better protect ranchers by requiring that only infected animals be slaughtered, instead of whole herds, and at the same time giving more leeway for park animals.
But wildlife advocates said it wasn’t enough.
“It still entrenches livestock management techniques to be used on native wildlife,” said Darrell Geist, habitat coordinator for the Buffalo Field Campaign, an activist group that has protested Yellowstone bison slaughters since the 1990s.
Environmentalists like Geist are quick to cite veterinarians, who say wild animals develop natural immunity to brucellosis. And they add that the chance of a bison infecting a cow is close to zero.
“But it’s still a possibility,” said Vincent Smith, a visiting professor of economics at Montana State University who researched the brucellosis issue for the conservative think tank the American Enterprise Institute.
Indeed, state officials in Montana, Wyoming and Idaho insist that the only reason no bison has ever infected a cow is because of their zero-tolerance policy.
But environmentalists and some sportsmen suggest that a wiser approach would be to treat bison like all other big-game animals in Yellowstone and allow them to live not just in the park but along a buffer of public lands around the park where they could be managed through regulated hunts. The cattle industry has resisted this.
The result of this push-pull is that bison control has become more ad hoc in recent years. Now Native Americans hunt some, others are herded back into the park with helicopters, and others are tested and shipped to slaughterhouses — an echo of the bison-ranch era in Yellowstone from the early 1900s through the 1960s. The meat is still donated to Native American tribes.