The argument First Nations groups made this week in an Edmonton courthouse wasn’t only aiming to block Alberta separatists’ petition drive toward a referendum, even if that was the specific, narrow goal of an injunction and a related hearing.

Sturgeon Lake Cree Nation and other litigants are challenging the very idea that a province can split from Canada, and in doing so sever their constitutionally protected First Nations treaties.

Athabasca Chipewyan First Nation (ACFN) is centred in northeast Alberta, but its ancestors followed caribou throughout what’s now Saskatchewan and Northwest Territories — and members today freely cross those boundaries to hunt, fish and trap, lawyer Kevin Hille told the court this week.

“Any constraint on those activities by an international border would violate those [rights],” Hille said.