Protecting a bridge to the Bitterroots

When a federal judge returned grizzly bears in the Greater Yellowstone area to the threatened species list in September, he cited the bears' fragmented range in the lower 48 states as one of his justifications. It is hard to call a species recovered, he argued, when it is isolated from other wild populations, as Yellowstone's grizzlies are.

Earlier this month, two conservation groups took an important step to ending that isolation. Twenty miles west of Missoula, near the confluence of western Montana's Clark Fork River and Ninemile Creek, the Vital Ground Foundation and Yellowstone to Yukon Conservation Initiative (Y2Y) purchased 52 acres that help connect two vast ecosystems.

The land lies adjacent to the Clark Fork and two Interstate 90 bridges where biologists have documented wildlife passing under the highway. The natural underpass makes it an ideal link between the Ninemile and Bitterroot mountain ranges, meaning it is especially valuable ground for grizzly bears. The Ninemile Range connects to larger cores of grizzly habitat that stretch to Glacier National Park and the Bob Marshall Wilderness while the Bitterroots open into millions of protected public-land acres in Idaho. These sprawling wildlands contain numerous projected pathways by which grizzlies ranging west and north out of Yellowstone might reconnect with those to the north in the Glacier region and beyond.

"The first time I keyed into the importance of the confluence of Ninemile Creek and the Clark Fork River was in 2001," says James Jonkel, wildlife management specialist for Montana Fish, Wildlife & Parks (FWP). "We were working with a bear known as the Ninemile Grizzly. On multiple occasions, he crossed underneath the underpasses. There's also continual elk movement across Interstate 90 there. It's one of the more important wildlife passages."

Regional Impact

Despite its designation as a federal recovery zone for the species, biologists do not consider the Bitterroot area to currently host a resident grizzly population. While the Ninemile Grizzly crossed the Clark Fork, he didn't stay in the Bitterroots, preferring the Ninemile area as home range. But bears are now venturing outside established recovery zones. This fall, FWP trapped one on a golf course in Stevensville, square in the bottom of the Bitterroot Valley south of Missoula.

Farther up the mountain spine that forms Montana's border with Idaho, the Ninemile-Clark Fork area features squarely in Vital Ground's larger conservation plan to protect crucial habitat connections between grizzly recovery zones. Drawn from a year's worth of meetings with bear biologists and managers, the land trust recently completed an inventory of 188,000 top-priority acres in unprotected ownership across Idaho and western Montana.

If protected, bear specialists believe these sites will contribute significantly to reconnecting fragmented populations between Yellowstone and the Canadian border. In partnership with landowners and groups like Y2Y, Vital Ground plans to utilize voluntary conservation easements and land acquisitions to safeguard identified top-priority areas-which range in size from 200 to 5,000 acres-over the next two decades.

"When people think about rural Montana, they imagine a few scattered cities and towns with lots of open space in between," says Ryan Lutey, executive director of Vital Ground. "But when you evaluate locations where high-quality wildlife habitat coincides with land use that's viable for maintaining connectivity between larger blocks of habitat, there are shockingly few opportunities remaining. That's especially true in western Montana, where the majority of our subdivision and development, transportation routes, and all of our associated activities are wedged in along narrow valley floors."

Biodiversity Bottlenecks

Beyond protecting a grizzly pathway to the Bitterroots, the Ninemile-area purchase safeguards valuable riparian and foothill habitat for many species. Ellis Mountain, a 240-acre conservation easement facilitated by Vital Ground in 2004, helps link the valley bottom to higher forestland to the west, allowing elk, deer and other animals to descend to the confluence area. Both waterways are also home to bull trout, a nationally threatened species and westslope cutthroat trout, Montana's state fish and a designated species of concern within the state.

"The main ridge on the west side of the valley is very, very important," Jonkel says. "A lot of different wildlife species come down through there. We've had bighorn sheep show up. We've had elk, we've had deer. Then the Ninemile Grizzly routinely came down to access the Ninemile wildlife corridor."

This month's purchase is the second of its kind for Vital Ground and Y2Y. The two organizations collaborated last month to acquire a similar parcel near the junction of northwestern Montana's Kootenai and Yaak rivers. Confluence areas like these represent natural bottlenecks for wildlife. In the Kootenai project's case, the purchase combines with a nearby Vital Ground property to solidify a documented wildlife corridor between the Yaak Valley and the Cabinet Mountains. Two subgroups of roughly 25 grizzlies apiece live in those areas, but development in the Kootenai Valley has led to very little documented movement between the small populations.

Now, bears ranging from the borderlands of the Yaak and southeastern British Columbia have a more protected route south into the Cabinet Mountains Wilderness Area. That range stretches down to the Clark Fork Valley near its junction with another waterway-Ninemile Creek. With its potential to connect the triangle of the Cabinet-Yaak, Glacier-Bob Marshall, and Bitterroot areas, the recent purchase site is a true connectivity hotspot. Throw in the presence of a functioning interstate underpass and the area's value to wildlife becomes even higher.

"This project helps secure one of the few locations where grizzly bears are able to cross I-90," says Nick Clarke, High Divide Project Coordinator for Y2Y. "It's an important step in ensuring that a variety of wildlife species can continue to move across the landscape."