The First Nation of Na-Cho Nyak Dun, and the Tr'ondek Hwech'in, along with the Yukon Conservation Society and the Yukon chapter of the Canadian Parks and Wilderness Society, filed their lawsuit in Yukon Supreme Court last February.

The case stems from the territorial government's adoption of a land-use plan for the watershed that litigants claim was unilateral and unlawful because it breached the co-operative process outlined in the territory's aboriginal land-claim settlements.

“Yukon government's unilateral decision to accept their own plan for the Peel undermines our final agreements," said Chief Ed Champion of the Na-Cho Nyak Dun. "Government's decision is also creating uncertainty for resource companies that want to do business in the Yukon, and it makes meaningful business relations between First Nations and resource companies difficult."

Karen Baltgailis, outgoing executive director of the Yukon Conservation Society, said the case "will set a precedent for how land claims are interpreted across the North. What it will determine is whether governments can simply pay lip service to the land claims agreements or whether they will actually have to listen to the spirit and intent of these agreements.

"That's important not only for First Nations but for all Yukoners because our land claims are Yukon law and they're embedded in the Canadian constitution. So it's every Yukon person's responsibility and every Canadian's responsibility to make sure that they are properly implemented."

Baltgailis also highlighted the growing importance of the 68,000-square kilometre watershed as a carbon sink and shelter for wildlife seeking refuge from climate change in the future.

"Areas of this size that are unroaded and intact are becoming increasingly rare in the world so it's really important to be able to preserve some of these really large natural areas for wide-ranging wildlife like grizzly and caribou and wolverines," said Baltgailis, currently the conservation society's co-ordinator for the watershed.

Tr'ondek Hwech'in Chief Eddie Taylor said the fresh water that the seven rivers of the Peel watershed provide is by far the most valuable resource within the Peel.

Though his community sought 100 per cent protection, Taylor said it is "willing to compromise" and accept the Peel commission's final recommended land-use plan.

"We will stand up for our rights in court. The Peel watershed is sacred to us as it was to our ancestors, and we want it to be around for our grandchildren."

The showdown comes in the wake of last month's landmark Supreme Court of Canada ruling granting aboriginal title to a First Nation in British Columbia, establishing the importance of consultation in negotiations between governments, First Nations and public organizations across the country.

The Yukon chapter of the Canadian Parks and Wilderness Society has been given permission by the court to record part of Monday's proceedings for archival purposes.

It said a silent half-hour vigil for the Peel will take place outside the law courts on the opening day of the hearing. In Dawson City, the Danoja Zho Cultural Centre will host a prayer circle between noon and 1 p.m. during the week-long case.

More than 50 elders from the communities of Mayo, Dawson, and Mackenzie Delta are expected to join First Nations leaders to witness the proceedings.