The Old Lady, Grandmother, Granny, Tsankui Theda, however she is called, is a watery deity borne of ancient times who’s said to live in a difficult-to-reach, frothy waterfall along the Lockhart, or Deshun Bedézé (Granny’s River).

Almost every Denes??iné knows some version of her story, which, astonishingly, harkens back 11,700 years to the Pleistocene epoch when beavers the size of bears (Castoroides ohioensis) roamed. The ailing Old Lady had asked for help, wanting blood from a giant beaver just harvested, but was denied. She refused to leave, and her lower body was absorbed into the rock of the falls where she said she’d stay until the end of time, helping people heal and ensuring an abundance of food and water in exchange for not disturbing her sacred abode.

It’s a creed that forms the spiritual apex for the 300-some people of the fly-in community of ?utsël K’é and another 600 in their Denes??iné (Chipewyan) diaspora, many of whom hang Tsankui Theda’s image next to the Virgin Mary in their homes. This hallowed grandmother figure has been a driving force, a mandate, behind a modern-day crusade to forever protect the biodiversity of her vast ecosystem. She is woven into a Denes??iné prophecy that says her waters will be a sanctuary when the globe reaches peak ecological destruction.

“We are creating a refuge that hopefully we will never need,” says Stephen Nitah, a former chief of ?utsël K’é who became lead negotiator for his people’s efforts to preserve the Land of the Ancestors, Thaidene Nëné, as Canada’s 47th national park.

“The prophecy speaks about a time in the future where the economy as we know it today collapses, societal structure as we know it collapses, food security is non-existent, a great migration of people will be looking to places that have water,” Nitah says. “You need to find deep water holes because fish will be our last sources of food and the water table is going to drop. And we’re starting to see signs of that already.”

Located in North America’s subarctic central Barren Lands, a vast expanse between Great Slave Lake and Hudson Bay, Thaidene Nëné stretches 400 kilometres across the 62nd parallel, sliced in a northwest-southeast direction by the treeline and the permafrost line. Two major drainage basins, the Mackenzie watershed, leading to the Arctic Ocean, and the Thelon watershed, emptying into Hudson Bay, support incredible biodiversity including birds, waterfowl, fish, small mammals, caribou, muskox, moose, wolverine and grizzlies.

Each fall, the Barrens burst into a riot of crimson when ground leaves turn and vitamin-rich berries erupt. Preserving that veritable breadbasket has required unwavering vigilance. Guided by the cultural axiom of Tsankui Theda, the ?utsël K’é Denes??iné have waged a strategic 50-year conservation battle that began, ironically, by thwarting federal government efforts in 1970 to turn Thaidene Nëné into a national park.

Nitah says the relationship then between Parks Canada and Indigenous Peoples was “dark and ugly.” Not wanting to lose their harvesting way of life to park expropriation, the late chief Pierre Catholique issued a resounding no to the proposal. Nonetheless, as power companies started staking out potential hydro sources along the waterways, the federal government permanently withdrew 7,349 square kilometres of potential parkland, including the Lockhart River, from staking, exploration and development. Hereditary chief Joe Lockhart famously told federal officials to “pack up their maps and go” during a second negotiation attempt in 1982.

Then came diamond mines.

By the late 1990s, two mines built along the migration route of the barren ground caribou coincided with the start of the herds’ precipitous decline and spurred interest in settling land claims and self-government agreements. ?utsël K’é is part of the Akaitcho process, a modern-day negotiation between five First Nations of the southeastern Northwest Territories and the federal and territorial governments to reinterpret Treaty 8.

?utsël K’é Elders observed that their Gwich’in and Inuvialuit neighbours were assigned land quantums (discontinuous pockets of surface and subsurface rights to areas that don’t allow for intact biospheres) under their final deals. Worried about preserving caribou habitat and their sacred watershed, the Elders suggested a park would allow for broader protections. A new conservation strategy was born.

Then-chief Felix Lockhart opened the door to Parks Canada discussions in 2000, but only if his people would participate as full partners without colonial overlays. Talks began in earnest, and within seven years the park study area ballooned to more than 33,000 square kilometres. But putting that giant swath of potential park under interim land withdrawal did not stop industry from knocking.

Dezé Energy Corporation proposed stringing hydro lines across Tsankui Theda’s watershed to power the diamond mines. All former chiefs and Elders from ?utsël K’é made impassioned presentations to the Mackenzie Valley Environmental Impact Review Board — Elder George Marlowe spoke while holding a jar of water from Kache — in opposition.

The project quietly died after Dezé was ordered in 2010 to find alternative routes. Three years earlier, the people of ?utsël K’é  had pleaded against Ur-Energy’s proposal to drill exploration holes in the adjacent Upper Thelon Basin, “the place where God began,” according to them. The review board rejected Ur’s proposal, saying it would threaten the spiritual and cultural well-being of the Dene.