Hooves plodded through an alleyway toward the trailer. A park ranger standing on a catwalk above the alleyway counted the individual units of Yellowstone’s population of the country’s national mammal as each entered the trailer. When the trailer filled, a representative from the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service placed locks on the trailer doors, a legal requirement and symbol that the trucks could travel on Montana’s roads.
This routine played out three times, and when the final trailer was loaded and sealed, the trucks took off. Another 45 Yellowstone bison off to slaughterhouses, where they’ll become meat for various Native American tribes. But that wasn’t the end of the day for the workers here — there were another 60 or so to prepare for shipment.
It was just another day at the park’s Stephens Creek Capture Facility, where bison are caught for slaughter each year. Park officials brought a group of bison advocates here Wednesday to watch. This season has been busier than the last, as harsh winter conditions have pushed more bison downhill from Mammoth Hot Springs than in recent years. The number of bison killed is approaching 1,000.
“And the winter’s not over,” said Rick Wallen, a Yellowstone bison biologist.
This all happens because of an agreement between the state of Montana and the park that calls for a population of 3,000 bison in the Yellowstone area. About 5,500 live there now. Officials want to remove as many as 1,400 from the population this year.
They cull the herd through public hunting and shipping bison to slaughter. Whether enough bison can be killed to reach the goal depends on how many bison migrate into the Gardiner basin — where the trap is and one place where they can be legally hunted.
Both hunters and the slaughter operation have reaped the benefits of this year’s large migration. Andrea Jones, a spokeswoman for Montana Fish, Wildlife and Parks, said hunters from five tribal nations and some licensed through the state have confirmed the take of 417 bison this winter.
Wallen said roughly 650 bison have been caught for slaughter so far and about 400 have been shipped, an average of roughly 100 per week since the beginning of February. That means they are approaching the goal, and since more shipments are scheduled and capture for slaughter is scheduled to run through March, they may reach a point where the work can stop.
“We’re going to have to make some hard decisions,” Wallen said.
Shipping bison to slaughter has long been controversial, and some of the most outspoken critics of the practice watched it happen Wednesday. Once the trucks full of bison left, the spectators were back on the tour bus. They watched from inside the bus as a vintage Chevrolet Blazer and four rangers on horseback lined up behind a corral full of bison.
“They call this domestication before assassination,” said Mike Mease, of the Buffalo Field Campaign.
The SUV and the men on horseback chased the bison into the narrow alleyways of the facility and into a holding pen. One-by-one, the bison entered a hydraulic squeeze chute.
Before operations began this year, park officials stamped parts of the chute with “2016-2017” in white lettering. They put that there so photos from the operations correlate with the correct year. That grew out of displeasure with old photos of bison wearing nose tongs surfacing online. Nose tongs haven’t been used here since the mid-2000s, park spokeswoman Morgan Warthin said.
Cattle producers worry bison could lead to transmit the disease to their herds, and even the perception of disease risk near their herds could subject ranchers to increased testing to ensure meat from infected animals doesn’t end up in grocery stores.
The disease is passed primarily through afterbirth. About half of Yellowstone bison are believed to have been exposed to the disease, though exposure doesn’t mean infection. Elk have transmitted the disease, but there has never been a documented case of bison transmitting the disease to livestock.
“A very small number of animals are truly threatening,” Wallen said.
After the blood sample is taken, the machine weighs the animal. Then, the animal is sorted into a pen based on weight and sex. Some come in bloodied, missing a horn or with a gash in their side.
Suspended above them is a ring of aluminum beer cans — Rainier in one pen, Pabst Blue Ribbon in another. Each ring is connected to a rope stretched across the pen. When it’s time to move bison out, park employees will use the rope and beer can halo to chase them. Until then, the bison wait their turn to board trailers some cold morning.