An Inside Look at Capturing Yellowstone's Bison

In mid-February the Stephens Creek bison capture facility (the trap) opened for business inside Yellowstone. The National Park Service runs the trap--a deadly cog in the controversial Interagency Bison Management Plan (IBMP). 

Two concepts sit at the heart of that plan: migration and social tolerance. Bison--in a race between starvation and spring--migrate out of Yellowstone and into Montana each winter in search of grass not locked away under ice or snow. But the Montana has no tolerance for bison outside the park near Gardiner and West Yellowstone. State officials claim this is because some bison are infected with brucellosis that can be transmitted to cattle. But there has never been a documented case of brucellosis transmission from wild bison to cattle. On the other hoof, wild elk have transmitted brucellosis to cattle numerous times and Montana has survived.

This unfounded fear of brucellosis was one factor leading to the creation of the IBMP—a court-ordered coalition of federal and state agencies and some Native American tribes. The IBMP calls for the capture of bison at Stephens Creek and for their shipment to slaughter in Montana. It also calls for a hunt (a firing squad, really) just outside the park to further reduce Yellowstone's bison population. This winter the IBMP goal is to remove 600-900 bison from Yellowstone's herd.

Along with members of the media and conservation organizations, I toured the Stephens Creek facility in the winter of 2016 and 2017 when bison were in the trap. The 2018 tour was cancelled due to security concerns. Unfortunately, no tours have been scheduled since then. I publish this post each year the trap is open so that what goes on inside is not a secret.

Below are photos I took during the tours. I've added captions that explain how bison are handled once captured at Stephens Creek. 

Processing began as NPS employees on horseback rode into the pen that holds captured bison. During the tours we observed the shipping of some bison and the processing for later shipment of more.

Shouting, whistling, and waving their hands, horseback riders ran the bison toward a second pen.

The bison were hazed from the second pen into a long chute that leads to a device with the brand name “The Silencer.” NPS employees used long poles to prod the bison out of the chute and into The Silencer, one at a time. 

The Silencer performs a number of functions. In this photo, a park bison biologist waiting to work stands to the left of the machine, while a supervisor on the catwalk makes sure the machine is ready for bison. (As of 2017, NPS had painted over The Silencer brand name on the equipment.)

We watched many bison go through The Silencer. They bucked and kicked and grunted, the whites of their frightened eyes obvious. Once a bison is in The Silencer, an operator slides levers that slowly moves the sides of the machine inward, squeezing the animal and holding it in place. Once the bison is still, a bar pushes the animal’s head to the side and holds it there so the biologist can draw a blood sample. The large needle used to draw blood is in the biologist's right hand in the photo. 

In addition to a blood draw, each bison was weighed, and its sex, age, and brucellosis status was determined. 

An employee showed us the blood samples. We were told that an NPS bison biologist analyzes the samples at a small lab at Stephens Creek. A positive test result means that a bison has been exposed to brucellosis, but does not necessarily mean that the bison can transmit the disease. Test results, say NPS officials, are not used to determine which animals are shipped to slaughter. Instead, they use them to understand the disease status of the population and to identify a few animals that are appropriate for brucellosis research studies.

After release from The Silencer, bison were directed to various holding pens, depending on age and sex. In the photo, female bison are seen through a small hole in one of the sheets of plywood that cover the fence of the holding pens. NPS officials said that if bison can't see past the plywood, can’t see an escape route, they stay calmer. 

These captured calves--born the previous spring--were waiting to be shipped to slaughter. This view is from a catwalk above the holding pens. An armed law enforcement ranger accompanied each of us when it was our turn to observe from the catwalk. 

About eight employees work on the catwalks. They open and close gates and keep bison moving. Four other employees draw blood and gather data at The Silencer. Workers often communicate with silent hand signals.

Once a bison has been processed and assigned a number by a tag placed on its back, it's ready to be shipped. The blood on this bison is either from an injury to this animal or from rubbing against another injured bison.

A trailer from a Native American tribe backed up to the loading gate, and the door of the trailer was opened. Bison were released from the holding pen and hazed down a chute. NPS employees prodded the animals with long poles from above to make them step through the open door of the trailer. 

In this photo, sixteen bison were in one of these trailers and fourteen in the other. Once the bison were loaded, the trailer was sealed. The trailers left together, followed by a Montana Department of Livestock law enforcement officer in a DOL truck. The officer was armed and ready to shoot the bison in case there was an accident and a bison escapes or was injured. We were told this procedure is required by the state of Montana. 

Since 1985, more than 12,500 bison have been captured and sent to slaughter or killed by the firing squad, according to Buffalo Field Campaign. During this bison season, 600 to 900 more could be killed. 

The original bison management plan requires this capture and slaughter and hunt. In 2016, an NPS spokesperson told us that they have outgrown the old plan. In 2017, a different spokesperson said that it could be up to ten years before a new plan is in place. 

Early this year, the NPS said they want to evaluate bison management based on new scientific information and changed circumstances. They want to explore ways to reduce bison being sent to slaughter, while continuing to work closely with Tribal Nations and agency partners in bison management. In the meantime, this capture and slaughter and hunt will continue.

Since 1952 the image of a bison has appeared on the arrowhead patch—the official emblem—worn by NPS employees. In the time I spent touring Stephens Creek, I heard numerous NPS employees state that they do not want to be sending these genetically pure bison to slaughter. They added, however, that they are required to do so by the IBMP. I was also told that the Montana Department of Livestock wants a quicker return from Yellowstone's current population of around 5,000 bison to the IBMP target of 3,000. To reach this target population, of course, even more bison--our national mammal--must be killed. 

The Interagency Bison Management Plan 

controls the shooting, capture, and slaughter of 

Yellowstone bison our national mammal.

This court-ordered coalition is composed of eight members:

National Park Service

USDA-Forest Service

USDA-Animal and Plant Health Inspection Service

Montana Department of Livestock

Montana Fish Wildlife and Parks

The Confederated Salish and Kootenai Tribes

The Inter Tribal Buffalo Council

The Nez Perce Tribe

The two annual IBMP meetings are open to the public.
If you want to speak for bison,

public comment is allowed at each meeting.

Next meeting: April 13, 2022 in Bozeman, MT.

Rick Lamplugh writes and photographs to protect wildlife and wild lands.

His bestselling In the Temple of Wolves; its sequel, Deep into Yellowstone; and its prequel, The Wilds of Aging are available signed. 

His books are also available unsigned or as eBook or audiobook on Amazon.

All photos by Rick Lamplugh