The Ross River Dena Council is suing the Yukon government, challenging hunting permits issued for the region.
They say the Yukon government has failed to properly consult the Dena Council about the big game hunting permits issued each year in the region.
The suit was filed last Thursday on the eve of the 2014 hunting season.
Legal documents filed in Yukon Supreme Court point to seven First Nation traplines in the area. The First Nation says hunters are adversely affecting traditional rights of Ross River members.
Environment minister Currie Dixon says his government got no warning about the lawsuit.
"Of course, we are surprised," he says. "The implications or potential implications of this claim are very profound and we are very concerned with them."
Dixon says the suit will not affect the current hunting season.
The Ross River Dena recently won a lawsuit over consultation on mineral exploration in the region. That forced the government to change the rules for prospectors working in Kaska-claimed territory.