A tiny Dene community in the Northwest Territories and the federal government agreed on Friday to begin formal talks to create a new national park.

The park, to cover between 25,000 to 38,000 square kilometres, would include the most pristine part of the deepest lake in North America, Great Slave Lake.

A fire-feeding ceremony was held to mark a reversal of position for the people in the tiny Dene community of Lutsel K'e.

Thirty years ago, they turned down a proposal to create such a park, fearing it would interfere with their hunting rights, as it had done with First Nations farther south.

"For thousands of years our grandmothers and grandfathers lived off the land and the land is very much a part of our people, and it's very important to protect that," community member Sayese Catholique told CBC Radio.

The community now views Parks Canada as an ally that may be able to prevent mining claims in the region from disturbing its main food source, caribou.

"We've noticed that the caribou are much skinnier. They're not coming around as much as they used to," said James Marlowe of the Lutsel K'e Dene. "And the elders say the mines are polluting the area through emissions from their oil stoves, the noise, the dust."

The proposed park, bridging pristine boreal forest and tundra, is home to herds of caribou as well as moose, and grizzly and black bears.

Aboriginal people in the area seek to call it Thaydene Nene National Park, which means "land of the ancestors."

If the Lutsel K'e Dene and Parks Canada stick to the schedule they have agreed to, boundaries for the park will be ready for parliamentary approval in three years.