The American Bison Is Returning to Its Home on the Range

The bison is back.

Numbering 40 million strong when Europeans arrived in the American West, the bison were hunted to near extinction by settlers, with just 25 animals remaining in the wild by 1902. Today some 10,000 bison are managed by the U.S. Department of Interior on federal land in 12 states. (Another 200,000 are in private hands, 51,000 of them owned by media mogul and conservationist Ted Turner.)

Extinction no longer is a threat for an animal that can stand six feet tall and weigh more than 2,000 pounds. But if the bison is to thrive as more than a tourist attraction, it needs to retake its place in the larger ecosystem. On Tuesday, the Interior Department released a plan for repopulating the bison beyond national parks.

“To achieve ecological restoration of bison across large landscapes, we cannot rely solely on DOI lands,” the report states. “Instead, we need to build partnerships with other landowners to weave together landscapes large enough to cultivate the full interplay between bison and the surrounding ecology, which would also help promote biological diversity of other plant and wildlife species.”

A key partner will be Native American tribes for whom the bison carries spiritual and historical significance, according to the report. (Interior Secretary Sally Jewell just might want to give Ted Turner a call, given that he’s the nation’s second-largest private landowner, with some 2 million acres under his control.)

The Interior Department also identified potential bison habitat on federal lands in Arizona, Colorado, Nebraska, New Mexico, and South Dakota.

The issue is that most bison are not exactly wild. Of the 17 herds managed by the Interior Department, only six are free-ranging; the rest live behind fences. Ranchers have resisted setting the bison free—as they have the reintroduction of the gray wolf—fearing the impact on their cattle. While the huge herbivores pose no predatory threat to livestock, bison can carry a disease called brucellosis that can infect cattle.

Those fears have kept the bison population at Yellowstone National Park—with 4,600 animals, it’s the largest—isolated owing to a prohibition on moving them elsewhere. That poses a problem, as biologists have determined that the Yellowstone bison belong to a key genetic line that survived near extermination.

“The Yellowstone bison genetic lineage is crucial to the long-term conservation of the species across its historic range,” the report’s authors wrote.

But there’s good news. Biologists have found that a long-running experiment to quarantine wild bison calves has proved successful at preventing them from contracting brucellosis. That has resulted in the transfer of the first Yellowstone bison to other areas. Now the Interior Department is planning to build a bigger quarantine facility so more bison can seed new populations around the country.

“However, significant work remains to restore the species to its ecological and cultural role on appropriate landscapes,” the report concluded.