Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In


Protect Our Parks

Culling the Last Wild Herd of Bison in Yellowstone National Park

These bison stem from an original population of 25 that survived mass killings. Yet, for the past 17 years, they have been sent to the slaughterhouse.

Herds of beautiful, massive bison move amongst the plains of their protector, Yellowstone National Park. These gentle giants are the last-known wild bison population in the entire world. This means that their DNA has not been tainted by breeding with cattle and domesticated bison. The Yellowstone bison stem from an original population of 25 that survived in Yellowstone during the mass bison killings of the 1800s and early 1900s. Yet, every year for the past 17 years, Yellowstone bison have been sent to the slaughterhouse. In 2017, more than 1,200 bison were slaughtered, the second most number of bison culled in the park’s history.

At the root of the culling is a disease called brucellosis.

“In part why bison are being killed and captured is because the state of Montana does not have a tolerance for bison in the state,” says Morgan Warthin, Yellowstone’s public affairs specialist. “That is driven by the fear of brucellosis.”

Brucellosis and Quarantine

Bison herd with two calves.
Bison herd with two calves. (Photo: Jerry Gates)

Brucellosis is a bacterial disease that is highly contagious for cattle, bison, elk and deer. It is transmitted by way of aborted fetuses, although there has never been a documented case of brucellosis being transmitted from bison to cattle. The bacterial disease, mostly carried by females, can cause infertility, abortions and scarce milk production, making it a very terrifying illness for those who depend on livestock for their livelihood. Cattle livestock makes up two-thirds of Montana’s agriculture industry, the largest industry in the state.

About 60 percent of female Yellowstone bison have tested positive for brucellosis. However, park officials note that this is not always a bad thing.

“Testing positive for exposure does not mean an animal can transmit the disease,” says Warthin.

However true this may be, Yellowstone National Park has no choice but to abide by state and federal law and keep the park’s bison population in check. In 1995, the state of Montana sued Yellowstone for bison that were wandering out of the park onto private land. The result? The creation of the Interagency Bison Management Plan (IBMP). The plan set a park limit of 3,000 bison in the park at a time. Since then, the park has had to adopt this population limit for bison in the park to avoid overflows. However, bison breed 10 times faster than the human population, making the population numbers rise up to 17 percent each year.

To avoid killing bison, Yellowstone officials believed they had found a middle ground for the beautiful beasts by sending them to Fort Peck, home to a quarantine facility and Native American reservation in northeast Montana where the animals would be tested for brucellosis instead of killed.The testing for brucellosis can take up to a year and involves blood testing as well as trial vaccines that have been tested on female and male bison. This vaccine is known as RB51, which was approved for cattle back in 1996, but not for bison yet.

Yet the state of Montana turned down the Fort Peck plan in the form of Bill 419 in February 2017 because ranchers believed it was still too risky to transport bison passed their cattle properties. The bill would have lifted a requirement that bison be certified brucellosis-free before being transported and then released somewhere else.

What Happens to the Bison?

Half buried, a lonesome Bison plow slowly to cross Yellowstone snowy landscape. Taken before sunrise in the middle of a brutal winter.
Half buried, a lonesome Bison plow slowly to cross Yellowstone snowy landscape. Taken before sunrise in the middle of a brutal winter. (: Surjanto Suradji)

With the door being closed on bison at Fort Peck, a portion of Yellowstone’s bison end up being shipped to slaughter. But first they are captured.

“The bison are rounded up and processed,” says Warthin. “This means that they are weighed, the biologist looks at their teeth to determine age and a blood sample is taken. Then the bison are put onto trailers and the size of the trailer depends on how many bison are put into a trailer. Typically, there are 10-15 bison in a trailer. When bison are processed they are separated into different pens based on their age so groups of similar size and age animals will be put together into trailers.”

“The National Park Service works with the Native American tribes,” says Warthin.

The National Park Service communicates with the tribes and lets them know how many bison are available.

“The tribes contract with trailers and drivers to go to Yellowstone to pick the bison up,” says Warthin.

Their big hides and plentiful meat then go directly to the Native American tribes who contracted with the drivers.

Fighting to Save the Bison

You can find many voices in the uproar over what is happening in Yellowstone and Montana, but you won’t find a louder voice than the Buffalo Field Campaign. This campaign, started by Mike Mease and Rosalie Little Thunder, is the only group working in the field to stop bison harassment and trapping.

Stephany Seay, media coordinator and volunteer for the Buffalo Field Campaign, has been a passionate member of the movement since 2004.

“What is happening to them now is the same thing that happened to them in the 1800s – it just looks different.” Seay says. “This issue represents a microcosm of what this culture (industrial civilization) is doing all over the planet,” says Seay when asked about the current bison management.

The Buffalo Field Campaign is a nonprofit organization working to save wild, migratory herds from harassment and slaughter since 1994. They are in the field occupying buffalo traps, locking themselves to gates, setting up tripods to block roads and other “in the field” type of work. The Buffalo Field Campaign also warns motorists in Hebgen Basin every year when bison are on their way to their calving grounds to decrease the number of bison killed by cars as well as to keep drivers safe.

What About the Elk?

Bull elk bugles in autumn near Yellowstone's Mammoth Hot Springs
Bull elk bugles in autumn near Yellowstone’s Mammoth Hot Springs (Photo: NPS/Neal Herbert)

Yet, the issue remains that bison are the only animal in Yellowstone not allowed outside of park boundaries. Elk, one of the main carriers of brucellosis, are allowed to roam free outside of Yellowstone limits. Meanwhile bison are being condemned in the park while also becoming free game when they cross park boundaries. State or federal agents are under jurisdiction to kill roaming buffalo outside of park limits.

“Montana livestock interests are in control of the state legislature, and they are anti-buffalo,” says Seay. “They always cry that it’s about brucellosis, but not even brucellosis-free bison are welcome anywhere. This is a war about grass and who gets to eat it,”

Another side to this issue is the elk and their rights to feeding grounds as well. Who is pushing for the elk? The hunters of Montana and Wyoming, some say. Elk is a popular big game animal for hunters, which means that elk have a built-in advocacy group of sorts.

“Elk bring in tons of money to Montana through hunting,” says Seay.

Hunting elk in Montana, on average, costs $25 for one elk permit as an in-state resident of Montana. The real money comes from out-of-staters who want a taste of a real Montana elk hunt. These permits can cost around $800-850 per elk. The state of Montana caps out at 17,000 permits for elk/big game. If you add the money spent by thousands of hunters looking for lodging, food and camping equipment in Montana, the state revenue from elk hunting increases dramatically. In 2014 deer and elk hunters that visited to Montana spend around $204.5 million, as reported by the Billings Gazette.

Bison Today

The Yellowstone bison issue continues to push at the forefront of the minds of Yellowstone and Montana state officials alike. With an almost record breaking culling in the year of 2017, not much has changed in 17 years since the Interagency Bison Management Plan took effect. The ranchers are caught in a net, bent on protecting their livestock to ensure their own economic survival. The bison are an unfortunate casualty. Yellowstone National Park officials find themselves in the awkward position of trying to protect the world’s last remaining wild bison while complying with a plan that mandates a portion of those bison are killed every year.

The bison is the national mammal, so it depends on our help to continue to roam the grasslands of Yellowstone and live out a long legacy. It has already survived near extinction at the turn of the last century. Yet, the bison of Yellowstone still face an uncertain future today.

“We have a long way to go, but we will never give up until wild, migratory buffalo know no boundaries,” Seay says.