Garth_Lenz-update-5856_0.jpgThe Flathead River Valley provides a vital link for wildlife moving between protected areas in the U.S. and Canada’s Rocky Mountain parks like Banff and Jasper. Connectivity between animal populations is critical to their long-term survival, as isolated “island” populations of mammals tend to disappear over time.

Fast Facts

  • The undisturbed nature of the Flathead provides important habitat for wildlife moving through the Rocky Mountains
  • The Flathead is a key part of the Yellowstone to Yukon Conservation Initiative
  • It links Alberta’s Waterton Lakes National Park with Glacier National Park in Montana
  • The long-term survival of large carnivores in the U.S. depends on the ability to move across the border
  • Permanent protection of the Flathead will ensure preservation of this globally-significant wildlife corridor.


“Natural biotic corridors exist along tributaries of the North Fork [of the Flathead], connecting the alpine and intermediate altitudinal zones with of the mountain ranges with the expansive floodplains of the mainstream corridor. The natural tendency of the biota is to use the stream corridors as primary emigration and immigration pathways.” - Dr. Jack Stanford 

“Despite the biological productivity of the area it is the most threatened portion of the Yellowstone to Yukon landscape. The biological functionality of the landscape is threatened by human actions ranging from recreation, resource extraction and probable major expansion of the Highway 3. Currently this landscape provides large mammals with the opportunity to move between the south side of Highway 3 and the north. This maintains what we believe …is a large, connected population unit. This unit includes animals from Glacier National Park and southward. To the north, in Canada, there is gene flow with animals in Waterton Park and the rest of the Canadian Rockies west and northward. This connectivity means that large mammal populations are more resilient to changing environmental conditions because they have more habitat and genetic diversity to draw on in times of stress.” - Dr Stephen Herrero, letter dated January 17, 2001 

“Our United States grizzly populations are dependent upon connections with grizzly bear populations to the north. These connections are important because they allow these populations to be larger, more resilient, and more likely to be viable in the long term. These populations are contiguous now, but if continued development along highway 3 continues, the connection across the highway may be broken. If this happens we will have another island population of bears and other carnivores like wolverine with associated increases in extinction risk.” - Dr Chris Servheen, Grizzly Bear Recovery Coordinator, US Fish and Wildlife Service, letter dated December 19, 2000.