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Room to Roam

Wildlife Migration in a Developed Landscape

Saline Lowland Range HabitatSaline Lowland Range Habitat

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Grizzlies, wolves, martens, cougars, and other predators roam to their hearts’ content along the North Fork of the Flathead River near Glacier National Park. “Elsewhere in the West,” said a New York Times feature, “people have gobbled up so much critical habitat, especially in the fertile valley bottoms, that many predators have either disappeared or are forced to carve out a living on the steep, more marginal slopes of the mountains.”

But in this spot, “Carnivores behave the way they would naturally, across a range of different habitats and elevations. … a grizzly bear can walk across the valley, left alone by humans – a situation almost unheard of in any valleys in the United States outside national parks and Alaska. … Long distance migration patterns [for moose and other species] are still intact.”

Why is this news fit to print in the New York Times? Because wildlife populations are losing the open routes they need – to find food, to survive in different seasons, and to produce new generations.

Personal Space

Animal species in the wild need food, water, and protection from the elements and sometimes predators. When these resources are found in different locations, when a species migrates to different areas over the course of a year, the animals need open, secure routes to get from one place to another.

For species to survive, individuals have to find mates but avoid inbreeding. Species need separated local populations that can connect and bolster one another in case severe drought or large fire or virus wipes out one of them.

When it’s time for new generations to strike out on their own, they need places to disperse, find mates, and reproduce. For example, an adult male grizzly bear may have a home range that extends 50 miles or more, so a young male looking to set up shop may have to go some distance to avoid confrontations with established males.

Wildlife cannot survive in disconnected “islands” of habitat, even if that habitat is ideal. In Montana, wild animals are having a harder time moving between habitats, because more and more people want to live in those same landscapes.

On the one hand, there is the obvious economic benefit of people moving in, buildings going up, roads being built, and commercial activity increasing. On the other hand, there is the cost to the wild places and wildlife populations that draw people here in the first place.

Residential subdivisions and commercial developments are taking up habitat and breaking up migration routes between habitats. More development means more garbage left outside, more outdoor grills smelling of food, drawing wild animals into human areas where they can only get into trouble. People who purchase and build on larger sections of land because they want “open space” may disrupt even more habitat than do people who choose to live in more clustered housing developments.

When roads are built or expanded to serve development, more wild animals get hit by vehicles, and some species may not even try to cross roads, leaving them stranded from food sources and mating opportunities.

Not Just the Big and Famous

The grizzly, the mountain lion, and other big predators have large ranges, low population densities, and relatively slow reproduction, making them especially vulnerable when they are cut off from needed habitat. But all species face risks from habitat isolation, explains Bill Ruediger of the US Forest Service, who works on connectivity issues across the country.

Antelope, sage grouse, and other species prevalent in the eastern part of Montana need free movement through the sage and grassland habitat, sometimes including long seasonal migrations. Their travels are interrupted by fencing, highways, new housing on what was previously agricultural land, and structures built for mineral development.

Fish don’t stay in one spot – they naturally move long distances on rivers and streams to feed, spawn, and seek cooler spots when rivers are low and warm. When highways are built, streams alongside may be straightened and rip-rapped, resulting in loss of stream habitat. Where bridges and culverts are constructed, stream channels may be constricted, and the resulting boost in water energy can wash out banks and damage stream and riparian habitat as much as 10 miles from where the structure was built. If fish go into certain types of culvert, “it’s a one-way trip,” says Ruediger.

Meriwether Ranch, a proposed 700-acre development on the increasingly developed Big Hole River, has been welcomed by Silver Bow and Beaverhead counties, both of which urgently need the property tax revenues. But the development would include two bridges across the river. Montana Fish, Wildlife, and Parks, Trout Unlimited, and others have objected to these bridges, in part because the bank stabilization will affect natural vegetation and stream processes. Ironically, the bridges may ultimately harm the fishery, which is one of the development’s chief advertising draws.

Less glamorous species are at risk as well. Turtles routinely travel from pond to pond, and they move from lower wetlands to upland habitats in order to breed. If roads are built through their customary routes, their small size and slow pace make them highly vulnerable to being killed by vehicles. Similarly, frogs and toads can travel distances of five miles or more. “Imagine turtles and frogs trying to move out of the Bitterroot River,” says Ruediger. “They have a hard time not hitting a highway in that area.”

“The Essence of Nature With the Flavor of Life”

“Only time on an unfathomable scale could create a place so diverse and beautiful. Traditional cattle ranching continues amid islands, wetlands, streams, mountain vistas, mystical buttes, the incomparable Big Hole River, and access to over 120,000 acres. Just as rare as the place itself is your opportunity to choose from thirty-four home sites blended into the landscape, starting at $500,000. Meriwether Ranch, Melrose, Montana.”

Advertisement in The Wall Street Journal, April 4, 2003

“I Will Win”

“Those wild turkeys were walking through here, and I chased them out with a broom. Don’t worry, I didn’t hurt them! That’s why I built that big fence across the front of the property. Then I had deer and moose walking through here to get to the creek, and we had their droppings all over the place. So I built those tall fences on either side right down to the water. And now I’m clean, completely clean of wildlife. They may try to come back in, but I will win!”

A New Montana Resident

Strategies for Public and Private Lands

Wildlife advocates are using geographic information system (GIS) techniques and other technologies to figure out the locations of important linkage zones, although Bill Ruediger says long-time residents in rural areas can be the best source of information about the movement of wild animals. Not surprisingly, people and wildlife are both drawn to mountain valleys with rivers and streams.

IGBC has embarked on a major effort to identify and map critical wildlife linkages in the Northern Rockies, using computerized GIS technology to analyze road density, human development, vegetative cover, and riparian zones. Some 30 sites have been identified for attention by task forces. Member agencies of the IGBC have agreed to work toward better habitat connectivity on public lands under their management – for example, maintaining vegetation in valleys so animals can find adequate cover when they move from place to place.

(For up-to-date information on IGBC, visit .)

In contrast to many mountain states, Montana lands are only about one-third publicly owned, and public sections are often interspersed with private lands. Public land managers have various projects underway to assemble adjoining sections of habitat through purchases and land swaps – a notable example being the federal purchase of 8,000 acres adjacent to Yellowstone National Park from the controversial religious sect called the Church Universal and Triumphant.

Where land remains in private hands, habitat connectivity depends on how much land is occupied by human activity, what sorts of development and open-space policies are in place, and whether private landowners are willing to accommodate wildlife. IGBC’s initiative emphasizes cooperation with landowners, local governments, and other private stakeholders adjacent to public lands.

Nonprofit groups such as the Nature Conservancy and state and local land trusts purchase land outright and promote the use of conservation easements – these are legal arrangements in different shapes and sizes that allow landowners to receive value for their land while protecting it from future development. Recently, a Montana ranch family put a conservation easement on more than 2,400 acres of critical wildlife habitat near Red Rock Lakes National Wildlife Refuge in Centennial Valley, generally considered an ecological treasure. Part of a major migration route for elk, wolves, and grizzly bears, the land was a prime target for development in part because people want to move near wildlife.

Wildlife advocates urge individual landowners to facilitate safe passage of wild animals through such means as careful placement of private roads and fences. Some livestock producers who allow wolves and grizzly bears to traverse their property are marketing their beef and wool products as “predator-friendly.”

Interagency Grizzly Bear Committee Membership

  • Bureau of Land Management
  • National Park Service Intermountain Region
  • US Fish and Wildlife Service
    • Region 1
    • Region 6
  • US Geological Survey Central Region
  • US Forest Service
    • Region 1
    • Region 2
    • Region 4
    • Region 6
  • Department of Fish and Game, Idaho
  • Department of Fish, Wildlife & Parks, Montana
  • Department of Fish and Wildlife, Washington
  • Game and Fish Department, Wyoming
  • British Columbia Provincial Ministry of Lands, Water and Air Protection

Roadways on the Radar

Recognizing that roads will continue to be built and improved, wildlife biologists and transportation engineers are figuring out how to make roads more “permeable” to wildlife, for example, by adding landscaped overpasses. More government and private research dollars are becoming available for this work.

Three examples of the emergence of the wildlife-transportation issue:

  1. The biennial International Conference on Ecology and Transportation is now an established event for researchers and practitioners, presenting research results and “best practices.” (ICOET Web site )
  2. A Web site called “Wildlife Crossing Toolkit” is maintained by a group including the San Dimas Technology and Development Center (US Forest Service), Western Transportation Institute (MSU-Bozeman), and the Federal Highway Administration. The site describes itself as a “one-stop shopping source of information on wildlife and highway interaction issues.” ( )
  3. Long the subject of jokes, “roadkill” was the subject of an article in the February 2003 issue of Planning, a professional journal for land use planners.

Highway 93

Montana Highway 93 between Evaro and Polson is often cited by wildlife advocates and transportation professionals as a model for wildlife-sensitive highway development. For years, the stretch was notorious for vehicle-wildlife collisions, which killed wildlife, injured humans, and caused vehicle damage.

When the Montana Department of Transportation (MDT) proposed that 93 be widened from two to four lanes, the Confederated Salish and Kootenai Tribes, which own the land, objected. Tribal members recognized the safety problem, but they insisted that wildlife be given consideration in the new design. "A lot of tribal members are active hunters and fishermen, and game is a treaty-protected resource," explained tribal biologist Dale Becker to Sierra Magazine. "Big-game species provide important subsistence for a lot of families. And the grizzly bear and gray wolf are revered as part of our culture."

After a years-long process of study, consultation, and negotiation, the stakeholders arrived at an agreement to work on a design "premised on the idea that the road is a visitor and that it should respond to and be respectful of the land and the Spirit of Place." The reconstructed highway will remain two lanes in many places (although it will be widened to three or four lanes in some spots), and it will include more than 40 structures, some of which will carry water, to allow wildlife to move freely over or under the roadway.

MDT’s Joel Marshik credits the direction of the project to the tribes’ deep respect for the land and commitment to all wildlife – “They feel as much for the vole as for the bald eagle.” [Learn more ]



A Sampling of Connectivity “Hot Spots”

  • Bozeman Pass, 10 miles east of Bozeman, between the Gallatin and Bridger mountain ranges, linking the Greater Yellowstone and Northern Continental Divide ecosystems. Threats to connectivity include residential development, traffic on I-90, and proposed coalbed methane development. Montana Department of Transportation (MDT), American Wildlands, Craighead Environmental Research Institute, and Western Transportation Institute are among those working on solutions.
  • Monida Pass links the Beaverhead and Centennial mountain ranges and, at a larger scale, links the Greater Yellowstone and Salmon-Selway ecosystems. Connectivity is threatened mainly by traffic on Interstate-15 and a railroad. IGBC, Greater Yellowstone Coalition, National Wildlife Federation, Bureau of Land Management, and Nature Conservancy are working on solutions.
  • I-90 from St. Regis to Lookout Pass, at the Idaho-Montana border, links the north and south ends of the Bitterroot Range. Threats are highway traffic and possible expansion of a ski area, which would increase recreation pressure. MDT, FWS, and FHWA are working to evaluate the impact of concrete barriers and high traffic levels on wildlife movement to better understand if special crossing enhancements or bridge expansions are necessary to allow wildlife passage. There are plans to monitor wildlife use of existing bridges to see if they already allow sufficient passage for sensitive species.
  • U.S. Highway 2, between Glacier National Park and Bob Marshall Wilderness. Threats include traffic, road construction, and tourist development on adjoining private lands. Recently, a FHWA-funded project on grizzly bear movements across this highway was completed by a Ph.D. student from the University of Montana. State officials are studying a proposal to widen this road from two to four lanes, which was advanced with the hope of increasing business in this economically depressed area.
  • Upper Madison/Raynolds Pass in southwestern Montana, links the Madison, Gravelly, and Centennial mountain ranges and Yellowstone Park. Threats include highway traffic, increasing subdivision, and housing development. Montana Fish, Wildlife, and Parks and private land trusts are working on solutions.

Linkages of the Human Kind

Protecting habitat connectivity requires cooperation among a diverse cast of characters: public land managers, corporate landowners, ranchers and other individual landowners, county commissioners, conservationists, land trusts, and John and Jane Public.

Chris Servheen, grizzly bear recovery coordinator for FWS and advisor to the IGBC, explains, “Some local publics are supportive [of linkage zones], but some are skeptical, and a lot don’t even know about the issue. We’re mounting an outreach effort, working with county commissioners and other local political forces on what this means for them.” IGBC works with the Boone and Crockett Club because a sportsmen’s group may be more “palatable to rural residents” than environmental organizations or government agencies. The approach is low-key. Rather than making formal presentations, Servheen says, “we’ll go have coffee with community leaders.”

MDT’s Joel Marshik says, “I don’t know that we have a lot of support for wildlife crossings specifically, but folks in quite a few different areas would like to do something about the safety aspects of wildlife on the roads. They don’t like to see a lot of dead deer out there.” In response to these concerns, MDT is experimenting with animal-friendly fencing, roadside vegetation that deters wildlife, and other measures. Montana has “so much wildlife,” he says, “we have to figure out where the issues are and how much to do. The public has to recognize that there is a dollar cost. How much they’re willing to spend depends on the local public.”

Marshik adds that habitat connectivity is part of the larger societal issues of human population growth and the interface between urban and wild lands. “We’re responding to a growing population that demands safe and quick transportation but also wants wildlife,” he says. “More people are growing up in urban areas, and they think nothing of putting houses side by side in the country, not recognizing what that does to the farmer, the rancher, and the wildlife manager. That’s part of the changing times, and it leads to changing values.”


  • Interviews with Bill Ruediger, USFS; Chris Servheen, USFWS; Joel Marshik, Montana Department of Transportation.
  • “Where the Bears and the Wolverines Prey: The Wildest Valley,” by Jim Robbins, The New York Times, 7/16/2002
  • “Seeking Safe Passage,” by Jessica Snyder Sachs, National Wildlife, 6/01/02.
  • “Identification and Management of Linkage Zones for Wildlife Between the Large Blocks of Public Land in the Northern Rocky Mountains,” by Christopher Servheen, John S. Waller, Per Sandstrom, US Fish and Wildlife Service, Missoula, Montana, updated 7/8/03, 83 pp.
  • “Report to the Interagency Grizzly Bear Working Group on Wildlife Linkage Habitat” (2001) and “The Relationship Between Rare Carnivores and Highways: An Update for Year 2000” by Bill Ruediger, Endangered Species Program Leader, USDA Forest Service, Missoula, Montana
  • “Gated communities go in with a bang,” by Ray Ring, High Country News, November 11, 2002.
  • American Wildlands, Bozeman, Montana.
  • “Activists promote ‘Yellowstone to Yukon’ idea,” Associated Press, 3/14/02.
  • “Montana Sect’s Downfall is a Boon for Conservationists,” by Jim Robbins, New York Times, 3/24/98.
  • “Brothers protect ranch from development,” by Nick Gevock, Bozeman Daily Chronicle, 1/4/03
  • Wildlife Crossings Toolkit Web site, US Forest Service and other partners,
  • Web site for the International Conference on Ecology and Transportation
  • “No More Road Kill?,” by Elaine Robbins, Planning, February 2003
  • “Making the roads safe – for elk, bears, and wolves” by Todd Wilkinson, The Christian Science Monitor, 12/10/2000.
  • “A Hallmark of Context-Sensitive Design” by Steve Moler, Public Roads, May/June 2002.
  • “How Did the Grizzly Cross the Road?” by Elaine Robbins, Sierra Magazine, July August 2003.

Information sources suggested by IGBC:

  • Servheen, C., J. Waller, and P. Sandstrom. 2001. Identification and Management of Linkage Zones for Grizzly Bears Between the Large Blocks of Public Land in the Northern Rocky Mountains. Pp. 161-198 in Proceedings of the 2001 International Conference on Ecology and Transportation, September 2001.
  • Waller, J., and C. Servheen. 1999. Documenting grizzly bear highway crossing patterns using GPS technology. Pp. 21-24 in Proc. Third Intl. Conf. Wildl. Ecol. and Transportation. Missoula, MT.
  • Servheen, C., J. Waller, and W. Kasworm. 1998. Fragmentation effects of high-speed highways on grizzly bear populations shared between the United States and Canada. Pp. 97-103 in Proc. Intl. Conf. Wildl. Ecol. and Transportation. Tallahassee Fl.
  • Servheen, C. and P. Sandstrom. 1993. Ecosystem management and linkage zones for grizzly bears and other large carnivores in the northern Rocky Mountains of Idaho and Montana. Endangered Species Tech. Bull. 18:10-14.
  • Servheen, C., R. Shoemaker, and L. Lawrence. 2003. Wildlife Use in Relation to Structure Variables for a Sampling of Bridges and Culverts Under I-90 between Alberton and St. Regis, Montana. In Proceedings of the 2003 International Conference on Ecology and Transportation, August 2003.

This vignette was completed in October 2003.

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