Where the bison roamed

'Good morning, ladies," says Karsten Heuer, brightly. The ladies – 10 bison heifers, each weighing as much as 1,000 pounds – don't look up, but you can be sure they notice the fit, stubble-faced human in their midst. These are prey animals: hyper-alert and wary of outsiders. Mr. Heuer's job title is "bison reintroduction project manager." He's overseeing an initiative to bring back the continent's largest land mammal to Banff, Alta., Canada's oldest national park.

On this crisp January day, Mr. Heuer is at Elk Island, also a national park, located 35 kilometres east of Edmonton. If you've ever seen a bison in Canada, it probably had Elk Island lineage. For the past century, the park – a grassy, 194-square-kilometre enclosure – has been a cradle of life for the species. Its personnel study bison, monitor their health and occasionally transfer them to other parts of the continent.

Mr. Heuer, a Parks Canada employee, is a conservationist in the deepest sense of the word. To preserve wildlife, he argues, we must keep it wild, although such an approach is difficult. You can find bison "display herds" – sad, penned-in clusters of animals – at parks and ranches across the country, but wild herds are comparatively rare. (There are three unfenced herds in North America. The Banff herd will be the fourth.)

Ironically, restoring a species to something similar to its wild state requires intensive human intervention. Handlers must manage the bison – enticing them into enclosures, then corralling them into chutes or shipping crates – without destroying their self-reliance. It's delicate work, all to revive an animal with Ice Age ancestry that was once abundant.

In the 19 th century, the population of North American bison – colloquially known as American buffalo – may have been as high as 30 million, with herds that stretched to the horizon. In Indigenous legends from the Staked Plain (Texas and New Mexico) the animals emerged, fountain-like, from a secret wellspring in the canyons.

By 1890, the bison had been reduced to a population fewer than 1,000 animals. Settlers shot bison from trains, drove them over cliffs on horseback and shipped them eastward to urban slaughterhouses. This was both an industrial endeavour – bison leather was used for mechanical belts in factories – and an act of war. For Indigenous people of the plains, the bison was a food staple, a clothing source and a religious symbol. With its destruction came the end of an entire way of life.

"Historians often talk about the bison era and the postbison era," says Lauren Markewicz, an educator at Elk Island. The destruction of the bison forced Indigenous people into starvation and then onto reserves. The Indian Act and the residential schools are postbison phenomena.

When the bison disappeared from the landscape they also became pop-culture icons. In their time, they'd been an obstacle to "progress" – herds sometimes derailed trains or held them up for days – but once they were gone, they turned into symbols of the mythic frontier. Their horned, woolly faces graced postage stamps, coins, state flags and the neon signs above diners.

The plains bison might be nothing more than a symbol had it not been for a pair of mixed-blood ranchers, Michel Pablo and Charles Allard Sr., who, in the late 19th century, amassed a genetically diverse herd from Nebraska, Kansas, Texas, Saskatchewan and their home state of Montana. After the U.S. Dawes Act of 1887, which carved up Indigenous lands into individually owned parcels, Pablo no longer had space to range his bison (Allard had since died), so in 1907 he sold the animals to the Government of Canada. That's how bison arrived at Elk Island, long after they'd been all but wiped out from the landscape. Without the Pablo-Allard herd, plains bison would be dangerously inbred, and the species could have reached a genetic dead end.

Today, however, bison have made an extraordinary comeback, thanks largely to Elk Island, which has 480 plains bison (descendants of the Pablo-Allard herd) and another 330 wood bison, a physically larger, endangered sub-species from Alaska and the Canadian North. The wood-bison herd was discovered in the fifties, during aerial surveillance near the Alberta–Northwest Territories border. Because of limited space, the park keeps its bison population in check by "transferring" surplus individuals, ideally to parks or First Nations bands – or to bison ranchers, if necessary.

Species reintroduction doesn't always work out, though, and Elk Island employees have had to learn from past mistakes. In 1978, they attempted to transfer a plains bison "starter herd" to Jasper National Park, but the animals scattered, some turning up near Grande Prairie, Alta., some 300 kilometres to the north. For bison to relate to their new environment as home, it's best if they give birth there. Mr. Heuer understands this animalistic connection to place. "Every time I walk by the river at the Banff Mineral Springs Hospital where my son was born," he says, "I feel instantly grounded by it."

The group of bison destined for Banff consisted of 10 pregnant heifers and six young bulls. They had been selected for genetic variety, but age diversity will come naturally in time. In Banff, the animals will be held in captivity until late spring 2018, long enough to calve twice. For approximately three years after that, Mr. Heuer and his colleagues will drive the bison from pasture to pasture in a 12,000-square-kilometre "reintroduction zone," acclimating them to the landscape until the fences are finally removed.

Driving bison is a complicated job, as much an art as a science. In the past, though, it was also a kind of sport. A slew of cowboy ranchers would swoop in on horseback, whooping and hollering, as the animals fled in panic. An eighties National Film Board of Canada documentary on Elk Island shows terrified bison being herded through a rickety corral system.

Today, that same structure has been rebuilt according to principles by Temple Grandin, the guru of compassionate livestock handling. The walls are concrete instead of wooden fencing, since bison are less likely to ram into solid barriers; the corridors are curvilinear, because circular movements have a calming effect; and the overhead catwalks enable humans to move among the animals unseen. The bison are corralled only rarely, to be examined by veterinarians, inoculated against diseases and potentially selected for transfer to other locales. To nudge a bison through the system, park employees silently assert their presence by leaning from the catwalk at strategically determined places. "Instead of pushing the bison to where you want them to go," says Pinette Robinson, an Elk Island resource management officer, "you entice them forward."

Directing bison on the ground is more delicate still. Mr. Heuer and his team use a technique called low-stress stockmanship, which requires an understanding of how wild animals relate to space. Mr. Heuer imagines a set of two concentric circles surrounding each bison. The outer bubble is the pressure zone: step into it, and the animal focuses on you and maybe backs off. Move into the inner bubble – the flight zone – and the animal will scamper away or potentially attack.

"It's all about working the narrow space between the two zones," Mr. Heuer says. Handlers enter the pressure zone when they want to assert their presence; they head to the edge of the flight zone when they want the animals to move. The method of approach determines the direction the bison take. "These zones change every day," Mr. Heuer says, "so you must read whatever cues the animals give you."

When feeding the bison, Mr. Heuer moves carefully among them, noting the sideways glances or the movements of tails – making his presence felt without inciting panic. The goal isn't to train the animals but rather to tap into their wild instincts. "You've got to go in there with the right energy, because they respond to your energy," Mr. Heuer says. "You cue into the animals' mentality and the subtleties of what they're telling you. You occupy the same mental space that you would've had hunting bison hundreds of years ago. It's an archaic instinct."

On January 31, Mr. Heuer and his colleagues herded the 16 bison into shipping containers and trucked them 430 kilometres to a government-owned horse ranch. The next day, they lifted them by helicopter to a pasture in the Front Ranges at Banff National Park, a place that hasn't had wild bison since Confederation. Hopefully in time, the animals will make the park their home, and the mythic buffalo will be returned to a corner of the Great Plains.

For Indigenous people of the West, this is a step toward an important goal. In September, 2014, eight nations or tribes, including the Blackfeet and the Blood Tribe, signed the Buffalo Treaty in Montana, which committed signatories to bison restoration. Other nations from north of the border have since signed on. If the decimation of the bison was an act of conquest, the species' return is a symbol of rejuvenation.

For everybody else, it offers a chance to encounter living history. Bison are fabled, charismatic and, above all, wild. "To see one," Mr. Heuer says, "is to be knocked out of your orbit or sidetracked from your urban way of thinking. It is to be in the presence of a deeply instinctive, ancient form of life."