In the end, the answer was, “It depends.” It depends on the species of animal, slope steepness, vegetative cover, human use within and adjacent to the corridor, and corridor length. We frequently found human-tolerant species like elk, deer, and coyotes using 100-yard-wide constrictions, for example, whereas wolves, cougars, and lynx seemed to avoid anything less than 300 yards wide. Corridors across steep slopes required greater width, as did those without many bushes or trees. Little to no human use was best, we discovered, and where it did occur, predictability made a huge difference. (A small suburban neighborhood with people and dogs spilling into an adjacent corridor was worse than one fringed by a busy, fenced highway, for example.) Finally, there were the physical dimensions. All else being equal, the longer the corridor was, the wider it needed to be.
Although we couldn’t provide land developers, managers, and other people with one easy prescription for a functional corridor, we did create a simple series of sliding scales that not only matched corridor dimensions to a specific landscape and situation, but also helped form recommendations where such corridors had been lost. Where our guidelines were followed, we witnessed some remarkable results. After removal of a horse stable, army cadet camp, and grass airstrip from one such impacted corridor, for example, wolf use increased by 700% in 12 months.
It was every biologist’s dream—not only had we pioneered new research, but it was being used to improve the situation for wildlife on the ground. But the movements of Pluie and other tagged wolves, lynx, bears, cougars, and wolverines still haunted me with their message to think big: Single-valley and single-park approaches weren’t enough. Armed with my sliding scales, I reconsidered the Y2Y proposal and guesstimated inter-park corridor dimensions that, in some cases, would be hundreds of miles long. Assuming they were well forested, they would need to be tens of miles wide.
Even with low-intensity developments—things like selective forestry and predator-friendly ranching—I wasn’t sure such swaths of open land existed. And if they did, were they publicly owned or private? And would the people who lived and worked in these areas ever support such a scheme?
Curious, I called colleagues on both sides of the international border and visited the local university library. But I found no answers. Weeks passed, then months, and still the question burned in my mind. Was Y2Y possible? Finally I realized there was only one way to find out how a wolf or grizzly bear might move through the region: Walk the 2,200 miles from Yellowstone to Yukon myself.
Over the course of the next 18 months, I encountered ridge-top blizzards, dodged lightning storms, swam rivers, triggered avalanches, and encountered bears. During the journey, I ended a romantic relationship with my first hiking companion and began another with a second woman (whom I would eventually marry). Not only did we meet numerous people while walking and skiing the distance (loggers, trappers, hunters, fishermen, ranchers, canoeists, hikers, and off-road vehicle enthusiasts), but we also talked to more than 70 chambers of commerce and other community groups about the Y2Y idea, stopping in numerous towns along the way. The receptions varied—everything from warm, hearty welcomes to rooms full of scowling loggers—but the end result was always the same. Once we clarified that Y2Y wasn’t a huge national park proposal but a necessary system of reserves linked by lightly developed corridors, arms unfolded and suspicious looks softened to smiles.
On our final leg of the journey, we encountered two hunters who were drying out after five days of chasing Stone sheep in the rain. They ushered us inside, and offered us whiskey and a wood stove. After we told them of our travels, they asked the question on everyone’s mind: “So what did you find out about the wildlife corridors?”
Before answering, I explained that the line we’d taken from Yellowstone—zig-zagging up Montana’s Gallatin, Bridger, and Big Belt mountains and then the Continental Divide into Canada—was only one of many potential connections in the Y2Y system. From Yellowstone, for example, there was another, equally valuable route for wildlife along the Centennial Mountains, connecting to eastern Idaho’s Salmon Selway Bitterroot and Frank Church Wilderness areas before it, too, headed north to Glacier National Park.
“I was pretty skeptical when we started out,” I admitted. “But in terms of barriers to wildlife movement, the news is good. Only ten paved roads, only five railways, and of the unprotected lands we crossed, less than ten percent are private, of which half are in conservation easements.”
The two hunters threw me a blank look.
“That means they’ll never be subdivided or used for anything more than ranching,” I explained.
“Only ten paved roads?” asked one, wondering if he heard right.
I nodded, then qualified it with a summary of the hundreds of oil, gas, and forestry roads we’d crossed. “At last count, there’s a road, pipeline, or oil exploration cut-line in all but 292 of the 320 watersheds in the Y2Y region,” I said.
One of the hunters nodded.
“Those are the same reasons the two of us spent two grand to fly in here with a bush plane. Everything you’re talking about—especially the industrial forestry and gas development—it’s happening up here in northern British Columbia as well. It’s getting to the point where we can’t find a valley where someone isn’t going to roar in on a motorbike, Jeep, or quad and ruin our hunt.”
“I’m not against development,” he quickly added. “Hell, I work in the oil industry. But there are problems. It’s happening helter-skelter. We’re cutting off wildlife. There’s no greater plan.”
The look on his face as he reached for the bottle matched my own sentiments about the Y2Y region—a love for its wild beauty tempered by a worry that it might not be saved in time. I watched him take a few swigs, then explained how hundreds of scientists and environmental groups were working hard under the Y2Y banner, mapping, identifying, and, in some cases, already securing critical wildlife corridors in the region.
“Believe me, those corridors still exist,” I said, following up with the most encouraging discovery of the journey: In 2,000 miles of searching, we’d seen fresh signs of grizzly bears—tracks, digs, scat, rub trees, and the animals themselves—85 percent of the way.
We made a toast to the promise of Y2Y, and later that evening, as we prepared ourselves for bed, a pack of wolves echoed the sentiment, their howls fading into the black night. I imagined them padding along the same game trails we’d followed earlier that day, retracing our footsteps to the steep riverbank where my companion and I had lunched, the windy pass where we’d piled on clothing, and the valley where we’d camped on wildflower seeds as thick as snow. Maybe they would go farther south, I thought, traveling for days, even weeks. Maybe this was only the beginning of yet another extraordinary journey across the buckling canvas of Y2Y.
When the howling finally subsided, I rolled over, closed my eyes, and fell back to sleep with a satisfied sigh.
Karsten Heuer is a wildlife biologist, park warden, and author of Walking the Big Wild: From Yellowstone to the Yukon on the Grizzly Bears’ Trail and Being Caribou: Five Months on Foot with an Arctic Herd, both published by Mountaineers Books.
