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Oct. 5, 2021

How We Helped Bison Make a Huge Comeback

Earthjustice is using the power of the law to restore and recover wildlife — including bison.

A bison grazes at American Prairie.
Ami Vitale for Earthjustice
A bison grazes at American Prairie.

In the middle of Montana, a group called American Prairie wants to see thousands of bison like this one roam free across America’s iconic prairie landscape.

Earthjustice is using its legal skills to make possible the vision of a great American bison comeback.

A herd of bison at a lake in Yellowstone National Park in 1905.
Library of Congress
A herd of bison at a lake in Yellowstone National Park in 1905.

In the 19th century, white settlers and market hunters hunted bison nearly to extinction.

Yellowstone National Park, one of the last havens for wild bison, contained about two dozen individuals, the last wild bison in the United States. Together, they carried the fate of the entire species on their broad shoulders.

Bison group in the road near Frying Pan Spring in Yellowstone National Park.
Jacob W. Frank / NPS
Bison group in the road near Frying Pan Spring in Yellowstone National Park.

A coalition of conservationists and scientists set about to recover the American bison. They began breeding formerly wild bison found on private ranches with the Yellowstone herd.

As the population grew to almost 5,000, Yellowstone bison started crossing park boundaries. Some were captured and shipped to slaughter; others shot by hunters and state agents.

Earthjustice managing attorney Tim Preso.
Doug Loneman for Earthjustice
Earthjustice managing attorney Tim Preso.

In 2001, Earthjustice began a series of legal battles that slowly carved out room to roam for the burgeoning Yellowstone bison population.

One of those fights resulted in a historic event for bison conservation. In 2012, after years of cattle interests blocking efforts by Native tribes in Montana to reestablish the bison herds that historically roamed their lands, Earthjustice’s litigation successfully defended the transfer of some of the last wild bison in Yellowstone to the Fort Peck and Fort Belknap Reservations in northern Montana.

“It was a return of wild bison to the people for whom the wild bison had meant everything,” says Earthjustice attorney Tim Preso, who began his legal career protecting bison.

Yellowstone bison exit the trailers at Ft. Peck Indian Reservation in 2019.
Jacob W. Frank / NPS
Yellowstone bison exit the trailers at Ft. Peck Indian Reservation in 2019.

After Earthjustice’s successful litigation, a new chapter of bison restoration began on the Great Plains where bison formerly roamed.

“When you have a people that have a history … with these magnificent animals, their absence has been felt tremendously. … And now that they’re back, our people are more centered,” says Stoney Anketell of the Fort Peck Tribal Board.

A bison roams at American Prairie.
Ami Vitale for Earthjustice
A bison roams at American Prairie.

Now, American Prairie want to go further in returning more bison to their ancestral home.

For nearly 20 years, the conservation organization has been buying up private ranching land in Montana from willing sellers and connecting it to existing public lands. The group’s goal is to establish a 3-million-acre nature reserve with thousands of bison.

Bison along Rose Creek in Lamar Valley in Yellowstone National Park.
Neal Herbert / NPS
Bison along Rose Creek in Lamar Valley in Yellowstone National Park.

When bison thrive, so does everything else on the prairie.

As they forage for grass, their powerful hooves and hungry mouths manipulate the landscape so fundamentally that they turn back the clock on spring, lengthening the growing season and creating greener and more nutritious grasses overall. The impact is so dramatic, scientists can see it from space.

A prairie dog takes in its surroundings at American Prairie.
A bison wallows on the ground at American Prairie.
Ami Vitale for Earthjustice
A prairie dog takes in its surroundings at American Prairie. A bison wallows on the ground at American Prairie

Bison foraging also creates ideal habitat for creatures like this prairie dog, which in turn feed coyotes and other natural predators.

Even in death, bison create new life. When left on the prairie, bison carcasses laden with seeds from wallowing in the dirt can eventually burst into clusters of wildflowers and new grass, which then attract birds, bees, and even pronghorn antelope.

A sign opposing bison outside American Prairie in Montana.
Ami Vitale for Earthjustice
A sign opposing bison outside American Prairie in Montana.

But some Montana cattle ranchers don’t share American Prairie’s vision. Based on an unfounded fear that bison could transmit a disease called brucellosis to their cattle, local ranchers successfully pushed to invoke a draconian county ordinance that required all the bison to be captured and tested — a process so stressful that the bison can die from it.

That’s when attorneys from Earthjustice’s Northern Rockies office came in. They helped negotiate an agreement in 2021 that calls for American Prairie to test a representative subset of its bison herd and share information with the community. Members of the ranching community are also invited to attend all the handling events.

The plan is meant to build trust and find common ground between the two groups, and it’s already starting to work.

Scott Heidebrink, right, is the bison restoration manager at American Prairie.
American Prairie
Scott Heidebrink, right, is the bison restoration manager at American Prairie.

Bison restoration manager Scott Heidebrink says that the plan Earthjustice negotiated allows American Prairie to continue “providing a proof of concept for pragmatic rewilding in the 21st century.”

If other large-scale rewilding projects are to succeed, American Prairie’s experience demonstrates that they must be able to adapt to or overcome significant cultural, economic, and legal barriers that make rewilding complex on the ground.

“We might view how to manage a resource a little differently, but the ranchers all love big, wide-open spaces. And they love wildlife,” says Heidebrink. “That was probably the most surprising thing to me is how much we actually all have in common.” 

A bison roams at American Prairie near sunset.
Ami Vitale for Earthjustice
A bison roams at American Prairie near sunset.
Map of Earthjustice offices.

Earthjustice’s Northern Rockies office protects large, intact ecosystems and seeks to build ecosystem resilience by reducing pressures caused by oil and gas development, logging, road building, and off-road vehicle traffic. Learn more.

Written by Jessica A. Knoblauch, senior staff writer at Earthjustice.