BILLINGS, Mont. (AP) — US officials were transferring 33 disease-free bison Monday from Yellowstone National Park to an American Indian reservation in Montana as part of efforts to reduce the slaughter of bison that migrate from the park.

Robert Magnan with the Fort Peck Tribes said the shipment was expected to arrive on the northeastern Montana reservation later in the day.

The shipment included bison and descendants trapped by park administrators under a legal agreement with the state of Montana that’s intended to prevent the spread of the disease brucellosis.

The bison were tested repeatedly during a Yellowstone-area quarantine run by the U.S. Department of Agriculture to make sure they were disease-free.

“We’ve run enough animals through this process that I’ve got confidence it’s effective,” Montana State Veterinarian Martin Zaluski said.

Brucellosis can cause pregnant animals to abort their young. It’s been eradicated in the U.S. except for the Yellowstone area, where it persists in herds of elk and bison.


Yellowstone has captured thousands of bison and sent them to slaughter for disease control over the past few decades.

Efforts to spare some of those animals have been going on more than a decade, but struggled in early years amid strong opposition from the livestock industry. Some elected officials worried about cows becoming infected.

Fort Peck has previously received Yellowstone bison, including 55 bulls over the summer. But those moved Monday included the first group of females to be transferred under current brucellosis testing protocols. The disease typically is transmitted through females, meaning they present a higher risk to livestock.

“The many years of trying to come together between the state, the tribes, the feds and (outside groups) have finally come to fruition,” said Chamois Andersen with Defenders of Wildlife, which helped pay for the shipping costs.

“This is a really good sign when you have these females that are the most scrutinized” being transferred, she added.

The bison moved Monday included 14 calves born in the government quarantine, said Joelle Hayden with the U. S. Agriculture Department’s animal health service.


There are 58 bison remaining in quarantine, she said.

Officials have announced plans to potentially kill or slaughter between 600 and 900 bison this winter to reduce the size of the park’s herds, which comprised almost 5,000 animals at last count.

Bison can be killed by hunters as they leave the park, and large groups are often captured at the boundary and sent to slaughter.

Some of those captured could end up in quarantine, but its capacity is limited.