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Robbie Magnan is seeing signs of progress.

The Fish and Game manager for the Fort Peck Tribes has watched 60 bull bison enter his quarantine pens so far this year — five in February and 55 in August. The program is meant to produce brucellosis-free bison that can enhance other herds or start new ones, and he’s overseeing the final round of testing at the tribal corrals. One of the bulls that arrived in February died, but the other four cleared the final hurdle, graduating the quarantine process. They’ve been released to join the reservation’s main bison herd.

The other 55 have a few months to go, but Magnan has already been taking calls from Native American tribes that want them when they’re ready.

For now, they’re doing OK out on the prairie.

“They’re really picking up weight,” Magnan said. “They’re looking real nice.”

More bison may soon be on the way. The Animal and Plant Health Inspection Service has a group of bison in corrals near Corwin Springs it hopes can go north soon. Yellowstone National Park has 24 in its pens near Gardiner and park officials will trap even more this winter. Maybe as many as 110 could enter quarantine next year, assuming the park can capture enough to make that happen.

The plan for this winter represents the immediate future of bison quarantine, with federal officials agreeing to fill double-fenced corrals with animals that could go through the program. APHIS and Yellowstone both have space to fill between the park’s bison trap and APHIS’ Corwin Springs facility, and they want to fill it.

“We’re collaboratively maximizing space for quarantine,” said Tim Reid, Yellowstone’s bison program manager.

This inertia suggests quarantine will become a regular feature in the management of Yellowstone bison, a somewhat consistent alternative that spares some bison from the slaughterhouse. All the government officials involved have confidence that the process works and that it doesn’t increase the risk of spreading brucellosis, a disease feared by the livestock industry because of the potential economic consequences of its spread.

Jay Bodner, executive vice president of the Montana Stockgrowers Association, said his group has followed quarantine closely and has been concerned about it. But so far, it seems to be working OK.

“I think the process that we have laid and put in place is working to a certain degree,” Bodner said.

There are still critics, most prominently the Buffalo Field Campaign, which has opposed quarantine for years. Stephany Seay, a spokesperson for the group, said quarantine doesn’t end the slaughter of bison. She called it a “tool of the oppressor,” saying the years bison spend in corrals take their wildness from them.

“It’s a livestock paradigm, plain and simple,” Seay said. “Instead of quarantine, we feel buffalo should be allowed to migrate.”

A number of other conservation groups are cheering this progress along, however, as it comes after years of conflict over the process. Chamois Anderson, of Defenders of Wildlife, said at a meeting of bison managers last week that this year’s shipments of bison show an improvement in relations between the various officials involved.

“We’ve come a long way,” Anderson said.


The entire idea of quarantine begins with brucellosis, a disease that can cause animals to abort. It’s known to exist in the elk and bison of the Yellowstone ecosystem. The disease can infect humans and cause undulant fever and was once considered a major public health risk, though that risk has been dulled.

Ranchers still worry about the spread of the disease. They worry it could lead to Montana losing its brucellosis-free status. Bodner said losing that status could cause other states to restrict cattle imports from Montana and make life harder for ranchers.

That fear is why controlling brucellosis is one of the stated reasons for the Interagency Bison Management Plan, which restricts where bison can go and calls for population reduction through hunting and ship-to-slaughter.

Critics of the plan, like Seay and the Buffalo Field Campaign, think that reason for restricting bison is bogus, arguing the same restrictions aren’t forced upon elk. There has never been a documented case of bison passing brucellosis to cattle in the wild. Meanwhile, elk have spread the disease.

“This isn’t really about brucellosis. It’s about the grass and who gets to eat it,” Seay said.

Ryan Clarke, a senior veterinarian with APHIS, said it’s not as simple to put the same restrictions on elk because they are harder to track and control. He also said bison have other characteristics that make them a concern.

“They’re a social animal that will interact with cattle and will actually breed with cattle,” Clarke said.

People involved in bison management have long seen quarantine as a potential way to erase the disease risk. It involves keeping the animals in groups separate from wild animals and testing them repeatedly for the disease. After a certain time of testing negative, they can be considered disease free.

Keith Aune, who worked for Montana Fish, Wildlife and Parks for three decades, said quarantine was talked about in the 1990s during the negotiations on the management plan, but that it was never the top priority.

“It was kind of put on the back burner,” he said.

In the early 2000s, though, he and other scientists tasked with answering a crucial question: Would quarantining bison actually work?

Beginning in 2005, scientists ran a bunch of bison at Corwin Springs through the testing protocols prepared by animal health experts. They proved that bison that repeatedly test negative for the disease would stay that way, meaning quarantine worked.

The animals put through those tests got new homes elsewhere, but that study didn’t lead to a formal future for quarantine. Clarke said it took time to put together the quarantine study’s results and to decide what should come next.

Quarantine got moving again in 2016, when Yellowstone proposed establishing a quarantine program at Fort Peck. The tribes had built a facility they believed would comply with federal standards, and they were eager for bison.

Initially, legal and political conflicts got in the way. Agriculture officials wanted the bison certified as disease free before they left the “designated surveillance area” — a term for the area around Yellowstone where brucellosis is known to exist.

In 2017, Yellowstone turned two pens at its bison trap near Gardiner into quarantine corrals, which require two layers of fencing to prevent contact with animals outside the enclosure. Once the work was done, park officials went back-and-forth with APHIS for months before getting their corrals OK’d for quarantine.

Meanwhile, the park had been holding some bison to get the program started. They’d been in the pens for months by January 2018, when vandals cut the fences and set them free, creating yet another hiccup. In response, Yellowstone beefed up security at the corrals and caught more bison, determined to make something happen.

That spring, regional National Park Service officials formally signed off on a final quarantine plan. More than anything, it represented agreement between NPS and APHIS. Included in the deal were dozens of bison being held at the APHIS corrals at Corwin Springs. The bison were part of a study that had been discontinued and could now enter quarantine.


Quarantine happens in three parts. First, Yellowstone traps bison and tests them for brucellosis. Bison that test negative can go into quarantine.

Next, the animals go through a series of regular tests before being certified as disease free. For bulls, this period lasts a year. For females, the process is longer and more complex — they have to calve during quarantine. For mature females, the process lasts 1.5 years. For immature females, it’s 2.5 years.

Those two parts can only happen at Yellowstone’s corrals or at Corwin Springs. The last part, called assurance testing, can happen at Fort Peck. It’s one more year in isolation with two more tests. Then, it’s over.

A year-and-a-half removed from the park service’s formal approval, government officials are happy with how things have worked.

“I think that the quarantine process is on the right foot,” said Marty Zaluski, Montana’s state veterinarian.

The process will evolve over time. The science already has. The third stage of quarantine lasted five years when scientists were first studying the process. Now it’s one year.

It’s possible other terms will shorten, too, like the amount of time for bull bison to be in quarantine, Clarke said.

“Over a matter of years, all the testing history and experiments that we accumulate may help us shorten the interval that animals spend inside quarantine,” Clarke said.

Advocates for the program have said there needs to be more space for it. Yellowstone and APHIS are committed to taking in bison for quarantine for as long as possible, but that’s only so many animals. Adding 110 animals this year — if it happens — would leave less space available for additional animals next year.

Reid said expansion is a complicated endeavor. A new facility would require land and someone to run it. So for now, it will be about maxing out what’s available.

“It’s just kind of a twisting of the spatial Rubik’s Cube,” Reid said.

A solution some see to this problem is letting the Fort Peck Tribes conduct the second round of testing, the longest part of quarantine. Tribal officials have lobbied for that, but APHIS has thus far been opposed to that happening outside the surveillance area. Lyndsay Cole, an APHIS spokesperson, said in an email that the conversation is “still active” but that no change is expected in the immediate future.

“We are still early in the development of this process and have to ensure the program develops and works for the bison and all parties involved to ensure brucellosis-free bison are being shared outside of the park and to the nations (sic) tribal lands,” Cole wrote.

Magnan is hopeful that will change, but he’s used to slow progress. He said he’d been working since 2008 to get quarantine going on the reservation. Now that it is, he thinks his program will prove itself.

“Once we keep getting more and more out of here, we can show that we can do this,” Magnan said.

For now, he’s thinking about how best to use what he’s got. He plans to split his two pens into four. There would still be enough land for each to be at least 60 acres.

He’s also looking forward to getting some females and calves, a change that brings him family groups of bison, something he’s looking forward to sharing with other tribes.

“Now we can look at having organizations starting out with family units,” Magnan said. “So they’ll get a little group of a family unit to start a herd.”

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Michael Wright can be reached at or at 582-2638.

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