GREAT WHALE, QUEBEC -- Aboriginal leaders in this remote sub-Arctic wilderness have vowed that the next major confrontation between native groups and the Canadian government involving land claims will be over a $6 billion hydroelectric project that they say will flood 2,000 square miles of ancestral hunting grounds, erasing a way of life that has existed for millenniums.

Emboldened by a highly publicized 76-day armed standoff between militant Mohawk Indians and Canadian army troops over a disputed golf course near Montreal, Eskimos and Cree Indians who live along the east shore of snow-swept Hudson Bay are reaching out to an unlikely source of support of their campaign to try to stop the next phase of what eventually will be the world's largest hydroelectric project.

The northern Quebec natives' new ally: Kayapo Indians from the rain forests of Brazil, who, recently linked to Canadian and U.S. environmentalists by the technology of the facsimile machine and computer communications, are trying to marshal worldwide pressure against the Quebec and Canadian governments to force them to halt construction of a 125-mile service road to the site.

The 3,060-megawatt Great Whale River project is part of a $62 billion hydroelectric plan designed to generate $25 billion in exports of power to the United States and to give the predominantly French-speaking province of Quebec the kind of economic self-sufficiency it needs as it pursues a more independent relationship with the rest of Canada.

While Hydro-Quebec, the state-owned public utility, has said it will go ahead with the project, using barges and even dirigibles, if necessary, to haul construction equipment to the site, spokesmen for the natives from Brazil and Canada said they will defend the wilderness at all costs.

Erik van Lennep, director of the Vermont-based Arctic-to-Amazonia Alliance, said the Kayapo activists will tour New York and the New England states, which have signed energy purchase contracts with Quebec, to lobby utility companies and prospective investors in the Quebec project.

"I am here to warn you: You must watch your land very closely or it will be taken away from you," Tapiet, a Kayapo Indian from Gorotire, a village in central Brazil, told a group of Inuit -- popularly known in the United States as Eskimos -- and Cree Indians at a meeting at the University of Montreal this month.

Speaking before the start of a study trip to this village on the southern edge of Hudson Bay by a group of 35 American environmentalists, Tapiet and Kuben'I, another Kayapo activist, said they united their fractious tribal members last year to stop construction of a series of dams that would have flooded more than 1,600 square miles of rain forest in central Brazil.

They did it after some of the chiefs of Gorotire, who were educated in cities, invested profits from Indian gold mining in video cameras, a satellite dish and an airplane and took their cause to support groups throughout Brazil. Tapiet and Kuben'I, who speak no English, have traveled widely in the United States and Europe with Terry Turner, a University of Chicago anthropologist who has worked with the Kayapo for 28 years, to promote wilderness preservation.

"For us, holding onto our land is like holding onto our lives, our way of living. We're here to make you aware of why we need our land, and of why you must shame your leaders to make them stop these policies of taking your land," Tapiet said.

His message appeared to strike a responsive chord with the Cree and Inuit leaders, who have observed with growing dismay what they call the ecologically ruinous effects of the first phase of the development plan. When completed, it will account for nearly a quarter of North America's hydroelectric power.

The Great Whale project, coupled with the already-operating Le Grande River project and the planned Nottaway-Broadback-Rupert project to the south, eventually is to harness the energy of 15 rivers in a 135,000-square-mile area of the Hudson Bay-James Bay region of northern Quebec.

Because of the huge size of the project and the fact that no environmental impact hearings have yet been held, environmentalists are demanding to know what ecological damage might result from an energy plan that will reshape the geography of such a vast region.

The first phase of the project, said Karen Lohr, chairman of the James Bay and Northern Quebec Task Force, flooded more than 4,400 square miles of land and ecologically altered 67,954 square miles.

Acidity of water in the new reservoirs, resulting from acid rain and decaying vegetation under the surface, has caused methyl mercury to leach from the soil, contaminating the water and the entire food chain to six times the levels considered safe for human consumption, she said.

Richard Drouin, chairman of Hydro-Quebec, contended that the first phase of the James Bay hydroelectric development, begun in the 1970s, has not harmed the people or the environment. In a recent speech in Montreal, he assailed the "tenacious myth" that northern ecosystems are fragile, saying that wildlife and plant life have survived the passage of glaciers and natural disasters and will do so again.

The protest task force, operating under the sponsorship of the Sierra Club, has brought together 14 North American environmental groups to oppose the project. Leaders said they will focus efforts on potential investors in Hydro-Quebec bonds. Besides making environmental arguments, the group plans to show that Quebec will be taking on $62 billion of debt at a time when its political stability is in question because of a growing separatist movement.

The 550 Cree and 400 Inuit of Great Whale village, a cluster of prefabricated houses built on the desolate sand dunes alongside an airstrip on the shore of Hudson Bay, say that from an ecological viewpoint, more damage will be done if the next phase of the project -- costing $6 billion -- is built just east of here.

For thousands of years, the Cree and Inuit have trekked and paddled canoes into the bush from the estuary of the Great Whale River to fish, tend trap lines and hunt caribou, bear, beaver and geese for their families.

Before they agreed to a 1975 land settlement that gave them $230 million and some control of 30,000 square miles in exchange for the province's right to develop the area's water resources, they lived in pole tents without electricity, sewerage, schools or any other public services, recalled Matthew Coon-Come, grand chief of the Quebec Cree.

Now, most of the pole tents are gone, replaced by modern, heated houses equipped with satellite television. There are schools, stores, a medical clinic, a social club and a new indoor hockey arena.

"But don't be fooled by what you see," Coon-Come said. "Our people still live off the land. They spend six months of the year in the bush, on their trap lines and in their bush camps. If they can't hunt and fish, they will be dependent on expensive packaged food that has to be flown here and that is culturally alien to them anyway."

Many Great Whale Cree and Inuit migrate into the bush each hunting season to fulfill the requirement of a guaranteed income program that the provincial government instituted as a way of getting natives off welfare. Now, however, many of them lash their canoes onto the pontoons of a seaplane that ferries them to their bush camps, while their children remain in white-run schools in the village.

Native leaders here say the hydroelectric project will wipe out even these last vestiges of their formerly primitive lives. They say that valleys in which the Cree and Inuit have maintained trap lines for generations will disappear and rivers in which they fish will be flooded, destroying the migratory routes used by the caribou and other animals they hunt.