Get ready for another big aboriginal rights decision from the Supreme Court of Canada.

On Friday, the Supreme Court will release a crucial decision on the wording of a 1873 treaty between the crown and the Ojibway Nation. The agreement, called Treaty 3, covers about 142,000 square kilometres in what is now a large part of northwestern Ontario and a small part of eastern Manitoba.

The legal rights of aboriginals have soared in public attention after the Supreme Court released its game-changing June decision that recognized the Tsilhqot’in Nation’sclaim to aboriginal title in a case called Tsilhqot’in Nation (Roger William) v. British Columbia.

Much of the discussion about the Roger William case focuses on its implications for British Columbia. Most aboriginal groups in the other provinces have ceded their land to the crown by treaty. B.C. is unique because First Nations claim title to most of the provincial land mass. This raises questions about the certainty of tenure for resource projects located in B.C., and it leads to the suggestion that projects located in the treaty provinces might be more secure because they won’t be affected by aboriginal title claims.

Yet the existence of a treaty alone may not provide absolute certainty of tenure. It all comes down to how the courts interpret the wording used in those treaties. This is why a lot of Canadian mining, logging and energy companies are anxiously awaiting Friday’s Supreme Court ruling.

Treaty 3 contains a “harvesting clause” which says the Ojibway have the right “to pursue their avocations of hunting and fishing throughout the tract surrendered” except on lands “required or taken up for settlement, mining, lumbering or other purposes by [the] Government of the Dominion of Canada.”

Natural resource companies believe the wording of Treaty 3 means that any rights enjoyed by aboriginals within the treaty lands are subject to the Ontario government’s right to allow those lands to be “taken up” and used for forestry, mining and other activities. Grassy Narrows First Nation disagrees and has mounted a legal challenge to a logging permit the province issued to a company now known as Resolute FP.

The Ontario Court of Appeal upheld the province’s right to issue the permit in a March 2013 ruling. Members of Grassy Narrows First Nation appealed that ruling to the Supreme Court, which heard oral arguments in the case in May.

Ontario’s provincial borders didn’t extend to the entire treaty area until 1912. Since the treaty specifically mentions that the right to take up belongs to the “Government of the Dominion of Canada,” the band argues that the government of the province of Ontario lacks the authority to issue any resource permits.

Ontario’s Court of Appeal ultimately held that the right to take up passed to the province when the federal government extended Ontario’s borders. Ontario’s Court of Appeal found that insisting on a literal meaning that would grant only the federal government the right to issue permits would create a “legalistic straightjacket,” because only provinces have the constitutional power to issue permits for things like mining or forestry. The court therefore rejected the argument that Ontario needs to obtain Canada’s approval before issuing any resource permits.

The Treaty 3 situation might be unique because much of the legal wrangling emerges from the federal government’s decision to transfer federal territory to Ontario at the beginning of the last century. Yet legal observers will be looking to see whether the Supreme Court has anything to say about the definition or process of “taking up” itself. This process, which is basically expropriation with a softer name, has led to litigation involving other treaties in Ontario.

There’s potential for the court to surprise a lot of people. One of the most overlooked aspects of the SCC’s Roger William decision is that it confirms the right of a province to allow certain developments to be built on aboriginal title land. Following that logic, it would be hard for the SCC to find that treaty language can limit the reach of a province’s take-up power.

Yet it’s best to wait until Friday. Appellate rulings come with the same caveat as mutual funds — prior performance is no guarantee of future results.

Financial Post