Bison Freed In Yellowstone Herded Toward Interior Rangers Capture Animals As Part Of Temporary Plan

The National Park Service has released 107 bison it held captive in pens near the park border, and it is hoping they now will stay in the park’s interior.

The animals were herded Thursday toward the park interior, said park spokeswoman Marsha Karle.

Park rangers captured the animals during the winter as part of a temporary bison plan that called for bison approaching private land along the park’s northern border to be shipped to slaughterhouses.

But as the death toll climbed toward 1,000 this winter, the Park Service backed off on the plan. Instead, it began testing captured animals for brucellosis, and sent only positive animals to slaughter. Those testing negative were held in pens near the park’s northern entrance at Gardiner, Mont.

With spring arriving in Yellowstone, the bison, including seven cows now wearing radio collars, were herded toward the park’s interior by rangers on horseback, Karle said.

“Green-up is starting to occur,” Karle said. “It’s time to get them out” of the pens.

Only time will tell if the animals will stay in the interior. After a steady diet of hay for the past couple months, some fear they’ll just turn around and come back to the pen.

“We’re afraid they’ve learned bad habits, that they’ll return and teach others the way back,” Karle said.

The agency had hoped a quarantine facility would be set up somewhere outside the park boundaries that could accept the bison.

Although the bison tested negative for exposure to brucellosis, they cannot be certified as disease-free until they undergo repeated tests while quarantined. That process can take more than a year.

Indian tribes had offered to set up quarantine facilities and Montana officials considered it but no final action was ever taken.

Brucellosis is a cattle disease that causes cows to abort. In humans, it causes undulant fever.

About half of Yellowstone’s bison have been exposed to the disease. The U.S. Agriculture Department had threatened to revoke Montana’s brucellosis-free certification if the bison were allowed to wander free on Montana rangeland.

That led to the plan under which state and federal officials captured bison for slaughter as they left the park.

The radio-collared cows will be monitored to see “if they head back and where they wind up,” Karle said.