In these wild borderlands of the north country, the territorial imperative is the law. Wolves, bears, even migratory birds, fiercely defend their turf from outsiders.

Now man, a relative newcomer, has entered the primeval struggle. Though encumbered by courts and legislatures, he, too is staking out competing claims to the wilderness.

The territory in question is a million acres of northern Minnesota called the Boundary Waters Canoe Area. The largest federally protected wilderness east of the Rockies, it is a picture-postcard land of pine forests where urban environmentalists can escape the mechanized world.

But in small towns like Ely, the economy depends on mining and logging. Long winter boredom is relieved by snowbiles. Summer power boating to trout streams is considered a constitutional right. So citizens here claim environmentalists are out to destroy their way of life by creating a "rich man's preserve" in their own back yard.

Thus the struggle over the territory is a conflict of class, of geography, of culture and philosophy which goes to the heart of the environmental movement.

After five years of court battles between the environmentalists, recreation groups and commercial interest, the fate of this unique wilderness is about to be determined in Congress. Hearings will he held shortly on competing bills sponsored by two Minnesota Democrats.

Rep. James L. Oberstar, who represents northeastern Minnesota, including the wilderness area, would allow logging, motorboats and snowmobiles in 40 per cent of the area.

Rep. Donald M. Fraser of Minneapolis, 200 miles downstate, backed by 50-co-sponsors, would allow access only to back-packers and canoeists.

The conflict has galvanized such national environmental groups as the Sierra Club, National Wildlife Federation and Izaak Walton League, which say the Oberstar bill, would set a dangerous precedent.

The leader of the environmental coalition, Friends of the Boundary Waters Canoe Area, is Miron Heinselman, 57, a retired scientist who specialized in forest ecology. A mild-mannered man with single-minded dedication. Heinselman is now a full-time activist.

"People who live in an urban society have no idea how drastically man has changed the world," Heinselman said, adding that wilderness - land undisturbed by timbering, farming, roads or human settlement - is a living laboratory.

"We're just beginning to understand life system - from plans to man. We ought not to destroy the last remnants of the natural world until we know more about it."

Sigurd Olsen, 78, a writer who lives in Ely, has also joined the Boundary Waters fight. "The average urbanite thinks wilderness is a place to go fishing," Olsen said. "But once you've been there a few days, you start noticing the sunsets and the calling of the loons. A certain calm descends on you.

"The preservations of wilderness is more than rocks, trees, beautiful lakes and rivers - it's the salvation of the human soul. It satisfies our hunger to experience the primitive, the natural world."

For environmentalists, silence is an essential part of the wilderness. "I've been canoeing when the motorboats zoom by," said Janet Green, head of the Friends in Duluth. "It's obscene.

Ely natives, most of whom seem to oppose the environmentalists, are equally fervent in defending their territory. At Jerry Bibeau's barber shop last week, a random smapling of customers viewed wilderness advocates with ananimous hostility.

"These people want to go back to the way the Indian lived," said Bibeau, who doubles as a city councilman. "But we're civilized here in Ely. It's like yelling in church." There's no way I'm going to paddle a canoe."

Chet Jahnke, 44, a iron ore miner, spends his day off fishing. With his motorboat, it takes 45 minutes to get to his favorite spot. If he had to go by canoe, "it would take three hours out of my day," he said.

Ernest Earjes, 69, a retired tax assessor, said the Fraser bill would discriminate against the elderly, "he only people who'll go in [to the Boundary Waters] will be the young people who can paddle," he said. "Punching holes in water is hard work."

Controversy over the Boundary Waters is nothing new. Since it was first set aide in 1902, battles have been fought over logging, roads, fly-in resorts, motor vehicles, dams and mines.

The current controversy stems from a unique exception Sen. Hubert H. Humphrey (D-Minn.) wrote into the 1964 Wilderness Act. Although wilderness was defined as an area "untrammeled by man . . . retaining its primeval character," timber cutting and motorboats were specifically permitted in the Boundary Waters Canoe Area.

Thus, the Forest Service allows motorboats along 21 designated routes which cover 60 per cent of the water area. Snowmobiles were banned last year after a Sierra Club suit. Logging is permitted in 40 per cent of the Boundary Waters, although only 10,000 acres are under lease.

In 1972, environmentalists filed suit to stop the logging of virgin timber in the area. They won a ban, but it was overturned last year on appeal. At Oherstar's request, timber companies agreed to wait until this summer for Congress to resolve the issue.

Boundary Waters has the largest virgin forests in the East.Colonades of 90-foot pines have stood there untouched for centuries.

In the 540,000 acres of virgin forest where only fire, wind and insect have taken their toll, "the entire vegetation is the result of natural processes," Green said. "There's an aesthetic, as well as a scientific value, to know you're not looking at a tree farm."

However, local residents - who sport bumper stickers reading "Sierra Club, Kiss My Axe" - claim that if no cutting is allowed the trees will grow old and die, creating vast acreags of "cellulose cemeteries," vulnerable to forest fires.

While Oberstar would exempt virgin timber from logging, he would allow cutting in a 405,000-acre area. The nearby 2-million-acer Superior National is a patchwork where economically feasible lumber sales are hard to assemble, he said. "The Boundary Waters area is important for the future growth of the timber industry," he added.

Whether it's timber, motorboating or another issue, the argument on both sides is over how much is enough. Environmentalists say 14,000 lakes and 16 million acres of National Forest timberland in Minnesota, outside the wilderness area, are more than enough for motorboat enthusiasts and timber companies, the latter argue that the 600,000 acreas proposed for complete wilderness under the Oberstar bill - and 14 million acres in the federal wilderness system - are more than enough for canoeists and ecologists.

What's the use of wilderness, if everybody can't use it?" asks Jerry Bibeau.

Green counters, "If everybody could use it, it wouldn't be a wilderness."