VANDO, Mont. - Greg Neudecker stopped his truck on a wooden bridge over Monture Creek and stretched out his arm toward the wilderness lands to the north, and Canada beyond that.

"This is the interstate," he said without irony, gesturing to the little stream, maybe 15 feet across. "Everything connects here, from the wild country down into this valley."

A corridor of the wild through the high country of North America - Yellowstone to Yukon - has long been a dream of environmentalists and biologists like Mr. Neudecker, who say that grizzly bears, elk, wolves and other four-legged commuters need help in looking for mates or new habitats. The great national parks of the West, they say, are becoming genetically isolated islands, cut off by development, urbanization and their ever-present iconic symbol, the barbed-wire fence.

But in places like this, on a patchwork of public and private lands, and through a tangle of human motivations that often have little to do with saving the planet, the wild road north along the spine of the northern Rockies is becoming reality.

Conservation and government groups say most of the 150 miles or so from here to the Canadian border, called the Crown of the Continent, is now largely protected through land buying and conservation agreements with private owners. In December the Nature Conservancy of Canada is expected to lock in the northern anchor - 98,000 acres just over the border in British Columbia that a forestry company has agreed to sell.

A result will be the creation of a sheltered land bridge where the animal societies of Canada and the United States can intermingle. Conservationists say linking the two pieces of the wildlife road will be as important for its political symbolism as for the animals that will make their way across - and could become more crucial over time if global warming changes alpine climates, forcing animals to migrate permanently.

"Spanning the international border means getting the cooperation and understanding of how natural systems work irrespective of boundaries, and that is a big deal and very, very hopeful one," said Steven J. McCormick, the president and chief executive of the Nature Conservancy in the United States., which has invested more than $45 million to preserve land along the corridor in recent years, an amount matched by the Nature Conservancy of Canada. The centerpiece of the project is a better understanding of how animals really move around. Knowing, for instance, that elk travel to their wintering grounds here in the Blackfoot Valley northeast of Missoula from the high peaks around Glacier National Park is one thing. Knowing exactly how they come - through what bramble of river valleys and passes - has allowed wildlife experts to focus precisely on which lands need protecting, and which ones, given limited resources, can be ignored.

Monture Creek, for example, and its equally humble counterpart to the west called Dunham Creek, are divided by a local landmark called Center Ridge. By a quirk of the glacial age, the three pieces of that triangle - upland and two waterways - wend their way directly back into the Bob Marshall Wilderness that begins north of Ovando. From there, animals connect with the river and ridge systems in Glacier National Park on the border with Canada .

A better understanding of animal mass transit has in turn allowed a downsizing of ambition about the Crown of the Continent project. The goal is not to create new wilderness or new public parks, say conservationists and wildlife experts like Mr. Neudecker, who works for the United States Fish and Wildlife Service, but rather to allow movement of animals through the landscape with the least possible human conflict.

Somewhat paradoxically, that has meant in some cases building more fences, not fewer. Here in Ovando, for instance, the owners of the Two Creeks Ranch had three miles of new electrified grizzly bear fence built and installed this summer, without charge to them, by a team of conservation workers. The $13,000 project sealed off the ranch's calving area, where the baby animals most vulnerable to hungry bears spend their first few days of life. The idea is that bears without easy food sources will keep on moving and not become a nuisance or a threat.

Much of the money spent by groups like the Nature Conservancy has gone into the bank accounts of ranchers like Karl Rappold, who has agreed to sell the development rights to most of his land near the town of Dupuyer, about 50 miles from the border. Those contracts mean that Mr. Rappold and his family can continue ranching, but it also means - a crucial point for the wildlife corridor - that the ranch can never be subdivided or developed.  

That arrangement has been repeated across roughly 170,000 acres of private land on both sides of the border. Mr. Rappold, whose grandfather started the ranch in the 1880's, said that selling the development rights had given him peace of mind.

"I want my grandson, and his children, to be able to saddle up and ride across this ranch," he said. And he said he had come to understand that the wild creatures are a big part of what makes the land work. "Without them, it wouldn't be the wild country that it is," he said.

Other ranchers have come to embrace the idea of a wildlife corridor for equally specific and personal reasons. Dusty Crary, who raises cattle south of the Rappold place and has also sold his development rights, said that his views about the land and nature changed suddenly, eight years ago, when his father was killed in a ranch accident.

"It made me stop and think, none of us are going to live forever, and how do I want this to be when I'm gone," Mr. Crary said. "It was a little transition for me, a realization that we have to pass things on."

Motivations like that also reinforce what conservationists and wildlife experts say is so unusual about the Crown of the Continent project. No one person is really building it. People are thinking locally and personally, and the resulting combined quilt of their contributions is what creates the corridor.

Other scientists and ranchers say the real question raised by the project is whether any of it is remotely natural. Mr. Rappold, for instance, is so fond of the grizzlies - and so convinced that a grizzly with a full belly will not bother his cattle - that he has begun feeding them. He puts out barrels of molasses for his cows, and then a few more, he says, for the bears. In spring, when bears are emerging from hibernation, he salts the high plateau with winter kills so that by the time the bears come down into his valley, they are no longer famished.

Some wildlife experts cringe at the idea of feeding wild animals, saying it trains them to look to people for food. Others say that keeping bears from becoming marauders is the priority, because the health of the corridor will depend on relationships across the human-animal border.

Others describe a sort of race between two evolving, interconnected forces - more animals, especially grizzlies, moving up and down the corridor, even as environmentalists work to minimize the impact.

Concern about humans crossing the border here - especially terrorists or other unauthorized travelers - is playing only a small role in the project planning, participants say, mainly because the Crown region, far from major population centers, is so remote and rugged.

"We're doing all these things to avoid conflicts, but maybe that just means the animals move on to the places where people aren't doing those good practices," said Geof Foote, a biologist and landowner here in Ovando.

That was apparently the outcome this year on the corridor's eastern edge. A late-spring storm devastated the wild chokecherry crop that grizzlies depend on, and so many of them simply strayed east, in some cases 35 to 40 miles from the mountains, farther from their regular grounds than most local residents had ever seen. One storm affecting one type of wild berry altered the animals' path, and for all the grand designs of man, the bears went where they needed to go.

Source:  The New York Times - http://www.nytimes.com/2004/12/02/national/02border.html?oref=regi