OTTAWA -- For the first time, the Supreme Court of Canada has recognized a First Nation's title to a specific tract of land -- a historic decision with major implications for contentious energy projects such as the Northern Gateway pipeline.

Thursday's 8-0 decision, which overturned an appeal court ruling, will essentially make it easier for First Nations to establish title over lands that were regularly used for hunting, fishing and other activities.

The landmark ruling is the Supreme Court's first on aboriginal title and will apply wherever there are unresolved land claims.

"The claimant group bears the onus of establishing aboriginal title," Chief Justice Beverley McLachlin wrote in the decision.

"The task is to identify how pre-sovereignty rights and interests can properly find expression in modern common law terms."

Title, however, is not absolute, the top court declared; economic development can still go ahead on land where title is established as long as one of two conditions is met.

Economic development on land where title is established would require the consent of the First Nation. Failing that, the government would have to make the case that development is pressing and substantial and meet its fiduciary duty to the aboriginal group.

In other words, the decision places a greater burden on governments to justify economic development on aboriginal land.

The court also makes it clear that provincial law still applies to land over which aboriginal title has been declared, subject to constitutional limits.

Chief Roger William of Xeni Gwet'in, one of six bands that make up the Tsilhqot'in First Nation, said he welcomed the Supreme Court's decision to grant a recognition of aboriginal title to 1,750 square kilometres of territory.

"First Nations across this country have taken legal action, entered into treaty, practised their language and demonstrated use of the land and through this they have supported us -- we thank you," he said in a statement.

The case dates back to the early 1990s, when the Tsilhqot'in First Nation first began using the courts and a blockade to stop logging operations in the area, setting off a two-decade legal odyssey that has cost tens of millions of dollars.

The Tsilhqot'in, whose territory is near Williams Lake, B.C., is made up of six aboriginal bands that together include about 3,000 people.

One of those bands, the Xeni Gwet'in, claimed aboriginal title over two areas it considered its traditional land. A forestry company attempted to secure access to those areas beginning in 1980s, eventually setting off the current court case.

In May of 1992, the Tsilhqot'in staged a blockade to prevent work on a bridge related to proposed forestry activity, which ended when then-premier Mike Harcourt promised there would be no further logging in the area without the consent of the Xeni Gwet'in.

Much of the area in dispute was turned into a provincial park in 1994, but the band and the province have been fighting over the remaining land ever since. The area at the centre of the court case represents about five per cent of what Tsilhqot'in band considers its traditional territory.

The trial, which began in November 2002 and continued for nearly five years, heard evidence that the Tsilhqot'in have been present in the area for more than 250 years.

But the trial also heard the Tsilhqot'in were "semi-nomadic," with few permanent encampments, even though they saw the area as their own and protected it from outsiders.

Jody Wilson-Raybould, British Columbia regional chief for the Assembly of First Nations, called Thursday's decision a "game changer." Unlike other provinces, British Columbia does not have modern-day treaties with its First Nations, so the ruling has significant implications.

"The court has clearly sent a message that the Crown must take aboriginal title seriously and reconcile with First Nations honourably," she said in a statement.

"The decision is an opportunity to truly settle, once and for all, the land question in B.C. -- where our nations are not simply making claims to the Crown under an outdated federal policy but where there must be true reconciliation based on recognition and where the outcome of negotiations is certain."