BADLANDS NATIONAL PARK, S.D. (AP) — Perched atop a fence at Badlands National Park, Troy Heinert peered from beneath his wide-brimmed hat into a corral where 100 wild bison awaited transfer to the Rosebud Indian Reservation.

Descendants of bison that once roamed North America’s Great Plains by the tens of millions, the animals would soon thunder up a chute, take a truck ride across South Dakota and join one of many burgeoning herds Heinert has helped reestablish on Native American lands.

Heinert nodded in satisfaction to a park service employee as the animals stomped their hooves and kicked up dust in the cold wind. He took a brief call from Iowa about another herd being transferred to tribes in Minnesota and Oklahoma, then spoke with a fellow trucker about yet more bison destined for Wisconsin.

By nightfall, the last of the American buffalo shipped from Badlands were being unloaded at the Rosebud reservation, where Heinert lives. The next day, he was on the road back to Badlands to load 200 bison for another tribe, the Cheyenne River Sioux.

Most bison in North America are in commercial herds, treated no differently than cattle.

“Buffalo, they walk in two worlds,” Heinert said. ”Are they commercial or are they wildlife? From the tribal perspective, we’ve always deemed them as wildlife, or to take it a step further, as a relative.”

Some 82 tribes across the U.S. — from New York to Alaska — now have more than 20,000 bison in 65 herds — and that’s been growing in recent years along with the desire among Native Americans to reclaim stewardship of an animal their ancestors lived alongside and depended upon for millennia.

European settlers destroyed that balance when they slaughtered the great herds. Bison almost went extinct until conservationists including Teddy Roosevelt intervened to re-establish a small number of herds largely on federal lands. Native Americans were sometimes excluded from those early efforts carried out by conservation groups.

Such groups more recently partnered with tribes, and some are now stepping aside. The long-term dream for some Native Americans: return bison on a scale rivaling herds that roamed the continent in numbers that shaped the landscape itself.

Heinert, 50, a South Dakota state senator and director of the InterTribal Buffalo Council, views his job in practical terms: Get bison to tribes that want them, whether two animals or 200. He helps them rekindle long-neglected cultural connections, increase food security, reclaim sovereignty and improve land management. This fall, Heinert’s group has moved 2,041 bison to 22 tribes in 10 states.

“All of these tribes relied on them at some point, whether that was for food or shelter or ceremonies. The stories that come from those tribes are unique to those tribes,” he said. “Those tribes are trying to go back to that, reestablishing that connection that was once there and was once very strong.”

HERDS SLAUGHTERED

Bison for centuries set rhythms of life for the Lakota Sioux and many other nomadic tribes that followed their annual migrations. Hides for clothing and teepees, bones for tools and weapons, horns for ladles, hair for rope — a steady supply of bison was fundamental.

At so-called “buffalo jumps,” herds would be run off cliffs, then butchered over days and weeks. Archaeologists have found immense volumes of bones buried at some sites, suggesting processing on a major scale.

European settlers and firearms brought a new level of industry to the enterprise as hunters, U.S. troops and tourists shot bison and a growing commercial market used their parts in machinery, fertilizer and clothing. By 1889, few bison remained: 10 animals in central Montana, 20 each in central Colorado and southern Wyoming, 200 in Yellowstone National Park, some 550 in northern Alberta and about 250 in zoos and private herds.

Piles of buffalo skulls seen in haunting photos from that era illustrate an ecological and cultural disaster.