Expert insights from: Daniel Kinka, director of rewilding at American Prairie, and Scott Heidebrink, director of landscape stewardship at American Prairie
American bison have come back from the brink, from just a few hundred animals in the late 1800s to roughly 440,000 today. But the numbers don’t tell the whole story. Most bison live in commercial herds. Far fewer are managed for conservation, and fewer still have the room to roam, graze and shape the prairie the way they have for thousands of years.
That’s where the real work begins. Through reintroduction, habitat restoration, genetic management and partnerships with tribal nations, conservation programs are returning bison to parts of their historic Great Plains range. American Prairie’s herd in Montana shows what’s possible for the bison and for the grasslands that depend on them.
Key takeaways
- Around 20,500 plains bison live in conservation herds, compared with about 420,000 raised commercially, so a big population doesn’t mean a fully recovered one.
- Bison aren’t listed as threatened or endangered, but wild, wide-ranging herds are still rare.
- No single hero saved the bison. Tribal nations, private individuals, conservation groups and government agencies did it together.
- Restoration is more than adding animals. It means protecting grassland, monitoring herd health and managing genetic diversity.
- American Prairie started with 16 bison in 2005. By 2025, the herd had grown to roughly 900 to 1,000 animals across nearly 50,000 acres.
- Bringing bison back can revive prairie processes, but results depend on habitat, herd size, movement and long-term stewardship.
How many American bison are left?
It depends on which bison you count. The U.S. Fish and Wildlife Service estimates about 20,500 plains bison live in conservation herds and another 420,000 live in commercial herds.
A smaller share of that conservation population is managed by the Department of the Interior: roughly 11,000 bison across 19 herds in 12 states.
| Bison population | Approximate number | What the number represents |
|---|---|---|
| Commercial plains bison | 420,000 | Animals generally raised for agricultural or commercial purposes |
| Plains bison in conservation herds | 20,500 | Herds managed for species, genetic, cultural or ecological conservation goals |
| Department of the Interior herds | 11,000 | A subset of conservation bison living across Department of the Interior and adjacent lands |
So the categories aren’t interchangeable. A big total doesn’t mean the species has fully recovered, not until wild, genetically diverse, ecologically functioning herds are back on the landscape.
What happened to North America’s bison?
Picture 30 million to 60 million bison moving across North America before the mid-1800s, most of them in the Great Plains. In just a few decades, that was nearly gone. Commercial hunting, habitat loss and a U.S. Army campaign meant in part to weaken the tribal nations that depended on bison drove the animals down to only a few hundred by the late 1800s.
Yellowstone was the last place in the contiguous United States to hold a wild, free-ranging herd into the 20th century. Everywhere else, a handful of small captive and privately managed groups became the seed stock for the earliest conservation herds.
Are bison still considered endangered?
No. American bison aren’t listed as threatened or endangered in the United States. But wild bison are still far less common than commercially managed animals. Conservation work continues to tackle habitat limits, isolated herds, genetic diversity and the loss of natural movement and selection.
In other words, bison have cleared the immediate risk of extinction, but their ecological comeback isn’t finished. Yellowstone, for example, holds the country’s largest public bison population and one of its best examples of a wild, migratory herd.
Who helped save bison from extinction?
No single person or organization saved the American bison. Private individuals worked alongside tribal nations, states, conservation organizations and the Department of the Interior to protect the animals that remained and build new herds.
The American Bison Society, formed in 1905, helped establish public conservation herds. In 1913, the society and the New York Zoological Society sent 14 bison to Wind Cave National Park. Descendants of the Wind Cave herd have since contributed to restoration efforts across the United States and Mexico.
How did American Prairie reintroduce bison?
American Prairie started its herd in 2005 with 16 bison from Wind Cave National Park in South Dakota and gave them something most bison don’t have: room to roam. Even with hundreds of thousands of bison in North America, relatively few are managed as wild animals with space to move across a large landscape. American Prairie’s restoration program is built to change that, giving a conservation herd more chances to graze, wallow, travel and interact naturally with Montana’s prairie.
Dr. Daniel Kinka, director of rewilding at American Prairie, put the ecological stakes plainly: “Bison are maybe the most important species in this ecosystem in terms of being an ecosystem engineer.”
But restoring that role takes more than turning animals loose. A herd needs the right habitat and enough room to move, graze unevenly and interact with other prairie species. That founding herd carries its own history, too. It traces back to the 14 bison the American Bison Society brought to Wind Cave in 1913.
American Prairie bison restoration timeline
1913: The American Bison Society brings 14 bison to Wind Cave National Park.
2005: American Prairie receives 16 bison from Wind Cave.
2023: The herd grows with 80 bison from Colorado’s Laramie Foothills herd and the Fort Belknap Aaniiih Nakoda community herd in Montana.
2024: Calves are born carrying a mix of Wind Cave, Elk Island, Yellowstone and tribal lineages.
2025: American Prairie reports roughly 900 to 1,000 bison across two properties totaling nearly 50,000 acres.
How do conservation efforts help bison herds?
Conservation isn’t one action. It’s many, working together. Bison conservation supports herds in several connected ways:
- Reintroduction: Moving bison to suitable parts of their historic range can establish new herds or expand existing ones.
- Genetic management: Transferring animals among herds helps preserve genetic diversity and reduce isolation.
- Habitat restoration: Protecting connected grasslands gives bison room to move and behave naturally.
- Health monitoring: Wildlife professionals track disease, reproduction, nutrition and population growth.
- Shared stewardship: Federal agencies, states, tribal nations and conservation groups coordinate management and animal transfers.
- Cultural restoration: Returning bison to tribal lands can renew cultural practices, food systems and relationships that go back generations.
- Ecological restoration: Wider-ranging herds can graze, wallow and move nutrients across the prairie.
It adds up to a shared blueprint. The Department of the Interior’s current bison strategy pulls these threads together: wild and healthy herds, genetic conservation, shared stewardship, and ecological and cultural restoration.
How do bison shape prairie ecosystems?
Bison are what scientists call a keystone species and an ecosystem engineer. Almost everything they do on the prairie, from grazing and wallowing to simply walking and leaving dung behind, reshapes the land around them. How much depends on herd density, habitat, rainfall, fire and how the land is managed. A restored herd works the prairie in several ways:
| Bison behavior | How it can affect the prairie |
|---|---|
| Selective grazing | Creates a patchwork of shorter and taller grasses that different wildlife species use |
| Wallowing | Forms shallow depressions that can collect water and create different growing conditions |
| Walking and movement | Disturbs soil and carries nutrients across the landscape |
| Producing dung | Returns nutrients to the soil and provides resources for insects and other organisms |
| Moving through snow | Can expose buried plants and open paths other animals follow |
Still, bison alone don’t rebuild a prairie. Healthy grasslands also depend on native plants, the right herd size, fire, water, habitat connections and the return of other native species.
For a closer look at grazing, wallowing and bison’s role as an ecosystem engineer, explore Restoring the Bison, Reviving the Prairie.
Scott Heidebrink, director of landscape stewardship at American Prairie, said the herd keeps moving — an average of 3 to 3 ½ miles a day across the year — so it grazes a shifting patch of ground instead of staying in one place. That constant movement is what leaves the prairie uneven, which is the point.
“What that’s doing is creating different heights of vegetation, which different birds, different animals, prairie dogs, pronghorn, mice and voles use at different times of the year,” Heidebrink said.
Why do genetics and partnerships matter in bison conservation?
Small herds carry a hidden risk: isolation. When a conservation herd stays cut off from others, its genetic diversity narrows over time. That’s where partnerships come in. Moving bison between herds keeps the gene pool healthy and reconnects populations that would otherwise stand alone.
The 16 bison released onto American Prairie in 2005 were a return nearly a century in the making. As of 2025, the herd has grown to between 900 and 1,000 animals across two properties totaling nearly 50,000 acres.
That exchange flows in both directions. American Prairie has distributed more than 550 bison to tribal and conservation herds across the country, working with partners including the InterTribal Buffalo Council. And in 2023, it welcomed 80 animals of its own — from Colorado’s Laramie Foothills herd and Montana’s Fort Belknap Aaniiih Nakoda community herd — descendants of Yellowstone bison, brought in to broaden the herd’s genetics.
Genetic management like this can ease the risks that come with small, isolated herds, but it’s slow, deliberate work: long-term monitoring and carefully planned transfers.
For Heidebrink, the payoff shows up in the calves.
“The calves born in 2024 represent a mixing of all of these lineages, from Wind Cave National Park in South Dakota to Elk Island National Park in Alberta, Canada,” he said.
Those calves are proof of how transfers among conservation and tribal herds can knit isolated populations back together. Still, no single herd — or single transfer — can secure the species’ future on its own.
How successful are American bison reintroduction efforts?
Bison reintroduction has pulled the species back from the brink of extinction and established conservation herds across the country. The Department of the Interior now supports 19 herds across 12 states, and tribal nations, states and nonprofits manage many more.
American Prairie’s own jump from 16 bison in 2005 to between 900 and 1,000 today is one local success story. But numbers are only part of it. A herd’s real success is measured by more:
- Enough suitable habitat
- Room to move and behave naturally
- Herd health and genetic diversity
- Ecological effects on the grassland
- Relationships with neighboring communities
- Return of bison to tribal and ancestral lands
- Long-term capacity of the land to support the herd
That’s why reintroduction is a long game, not a one-time release. Ongoing monitoring, habitat stewardship and collaboration decide whether a herd stays healthy and whether it contributes to the bigger work of ecological and cultural restoration.
See the bigger prairie restoration story
Bison are just one thread in a much larger grassland community. Watch Rewilding the American Prairie to see how bison, prairie dogs, burrowing owls and conservation partners are working to reconnect wildlife across America’s prairie.
Bison restoration frequently asked questions
What’s bison reintroduction?
Bison reintroduction is the work of returning animals to suitable parts of their historic range. It usually means choosing a release site, transferring animals, monitoring their health and genetics, and managing habitat so the new herd can take hold.
Are bison and buffalo the same animal?
Yes — in North America, “bison” and “buffalo” refer to the same animal: the American bison. “Bison” is the preferred scientific term, while “buffalo” carries long-standing cultural and everyday use. True buffalo, like the African Cape buffalo and Asian water buffalo, are different species.
Why aren’t all American bison considered wild?
Because most bison are raised in commercial or closely managed herds, often behind fences. Truly wild, free-ranging conservation herds have room to migrate, choose their own habitat, form natural social groups and interact with predators and other wildlife. Management varies from herd to herd, so the line between “wild” and “managed” isn’t always clear.
Why are bison protected if they are not endangered?
Because their value goes beyond population numbers. Bison remain vital to grassland ecology, Indigenous cultures and North American conservation history. Protecting conservation herds preserves the genetic diversity, natural behavior and ecological relationships that a headcount alone can’t capture.
Sources:
U.S. Fish and Wildlife Service. Plains Bison. Accessed July 2026. fws.gov/species/plains-bison-bison-bison-bison
National Park Service. Protecting Bison. Updated July 14, 2025. Accessed July 2026. nps.gov/subjects/bison/protecting-bison.htm
National Park Service. Bison Ecology. Updated May 4, 2026. Accessed July 2026. nps.gov/yell/learn/nature/bison.htm
National Park Service. The Bison Beat. Updated June 3, 2025. Accessed July 2026. nps.gov/articles/000/the-bison-beat.htm
