Yellowstone Rockies, USA

The Path of the Pronghorn Antelope Video
An icon of the American West faces new obstacles as it travels an ancient route through sagebrush plains.
Bighorn Sheep in Yellowstone Photo
Two centuries ago in Yellowstone, bighorn sheep were a common sight. Today, after decades of overhunting, competition with livestock, and habitat loss, just a couple hundred remain in the park.
Julie Larsen Maher ©WCS
Yellowstone Rockies Landscape Photo
The Yellowstone Rockies are home to the greatest concentration of large mammals in the contiguous United States.
Julie Larsen Maher ©WCS

Stretching from the Canadian border south through Wyoming, the Yellowstone Rockies harbor the three wildest ecosystems in the lower 48 states: the famous Greater Yellowstone, Salmon Selway, and the Glacier-Northern Continental Divide (also called the “Crown of the Continent”). This rugged landscape provides crucial strongholds for wolves, grizzly bears, lynx, bull trout, cutthroat trout, pika, mountain goats, bighorn sheep, and wolverines. Many victories for conservation have been achieved here, from the establishment of the world’s first national park in 1872 to the first federally-protected migration corridor in 2008, which safeguards the "Path of the Pronghorn.”

Climate change, energy development, human-wildlife conflict, and exurban development (also called “rural sprawl”) are increasingly altering this wild region, and the future of the landscape and the species it supports depends on continued conservation efforts and devising creative ways to help people and wildlife coexist.

Fast Facts

  • The Greater Yellowstone, Crown of the Continent, and Salmon-Selway ecosystems cover more than 62,500 square miles.
  • The Salmon-Selway ecosystem includes the largest roadless area in the lower 48 states.
  • Greater Yellowstone is home to the greatest concentration of large mammals in the contiguous United States and a complete assemblage of native carnivores.


Increasing rural sprawl, energy development, and motorized recreational activities all threaten the integrity and wildlife of this unique mountainous landscape. Protecting the long-term health of iconic North American species like grizzly bears, sage grouse, wolverines, and pronghorn remains a serious challenge and depends on effectively managing human development and energy projects, minimizing human-animal conflict, and protecting the connectivity of habitats across the landscape.

WCS Responds

WCS has a long history in the Yellowstone Rockies, beginning with our successful project to restore the bison population in the early 1900s. Today, WCS researchers are working throughout the region. We study and conserve the elusive wolverine, protect the migration corridor and wintering grounds for pronghorn antelope, minimize conflicts between people and grizzly bears and wolves, aid wildlife managers in preparing for the effects of climate change, and work to ensure that wildlife can continue to range freely across the open spaces of Montana, Wyoming, and Idaho.

WCS landscape and species analyses are now used by local land trusts to inform targeted land acquisitions and by state policymakers to reform laws on the hunting and trapping of wildlife, including wolverines, moose, and mountain lions. Our wolverine initiative led to the protection of key areas linking core habitats. In Idaho’s Lost River Sinks landscape, we’re working with the Department of Energy, the Bureau of Land Management, and Idaho Fish and Game to ensure that pygmy rabbits, pronghorn antelope, and sage grouse have a secure future within the largest intact sagebrush habitat in North America.

WCS is developing cutting-edge science and scenario-based planning for coping with the potential impacts of climate change on wildlife and their habitats across this vital landscape. We are working with planners and land managers to combat rural sprawl, and collaborating with landowners in the Crown of the Continent to restore beavers and the ecosystem services they provide. We work closely with the energy development industry to understand how impacts of extraction affect wildlife and their movements and to develop best practices. In the Centennial Mountains, with the help of dogs specially trained to detect scat, WCS researchers mapped the occurrence of large carnivores between protected areas of Yellowstone and Idaho. This led to the protection of wildlife corridors by closing more than 40 miles of roads and preventing development in a sensitive area.

WCS Projects

Corridor Conservation in the American West

Food, water, shelter, and the freedom to roam—these are the basic needs of wildlife. WCS-North America works to protect and interlink crucial wildlife habitats through field-based research, outreach, and policy.

From the Newsroom

Path of the Pronghorn: Leading to PassagesDecember 11, 2013

Scientists from WCS have worked for over a decade to protect pronghorn migrating along a 100-mile long path to and from Wyoming’s Grand Teton National Park. Jeff Burrell, WCS Northern Rockies Program Coordinator, knows that if this corridor is severed, pronghorn will be lost from the park.

Rise in Roadkill Requires New SolutionsMay 16, 2013

The U.S. highway system includes more than 4 million miles of road. Roads crisscross even the most remote parts of the country, fragmenting habitat and causing regular encounters between motorists and wildlife.

For Juvenile Moose, Momma’s Boys and Girls Fare BestAugust 24, 2012

Size often matters in the animal kingdom, with larger animals faring better than their compact counterparts. But a recent WCS study suggests that for a juvenile moose, mother’s presence—not body mass—is key to survival.

The Buffalo has Earned Recognition as our National MammalAugust 3, 2012

WCS has been leading bison conservation efforts since 1905, when William Hornaday co-founded the American Bison Society with Theodore Roosevelt. In addition to supporting bison and the landscapes they roam, WCS has joined efforts to craft the National Bison Legacy Act--Congressional legislation that would designate bison as our country's national mammal. 

Senators Seek to Name Bison 'National Mammal'May 25, 2012

In concert with the introduction of the National Bison Legacy Act in the U.S. Senate, WCS and its partners have launched a campaign to make the American bison our national mammal.


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