Scientists Are Documenting the Profound Impact of Human-Powered Recreation on Imperiled Wildlife during the Winter

Skiers, biologists, land managers, and wildlife enthusiasts are working together to find a way to protect the Teton bighorn sheep herd. If you would like to get involved or learn more, attend one of the upcoming community meetings in Jackson, Wyoming, on February 13 and 20, March 5th, and April 9.

By Hilary Eisen, policy director

The Teton Range in Wyoming is a special place for backcountry skiers. Its unmistakable skyline holds some of the best and most iconic skiing to be found in the world. The Tetons are also an important refuge for wildlife. Many species make their home in the Teton Range, including the threatened Teton bighorn sheep herd. 

Historically, bighorn sheep were abundant and widespread in the Tetons. Biologists estimate more than a thousand bighorns once lived in the range, although it’s impossible to say for sure. Every fall, they migrated out of the mountains to winter in warmer, drier low-elevation foothills. However, development and human impact have affected the bighorn’s annual migration patterns.  

Over the past several decades, bighorn sheep in the Tetons have stopped moving to lower elevations for winter in order to avoid humans. Now, they live year-round in the high reaches of the range. As a result, their population has dropped dramatically, to approximately 100 animals. Biologists fear this unique population may go extinct. 

Photo: Josh Metten

For a long time, we’ve understood that motorized recreation disturbs wintering wildlife, and land managers often close winter ranges to motor vehicles to protect vulnerable species. However, new research is showing that non-motorized recreation, like backcountry skiing, can disturb wintering wildlife, too.  

To better understand why bighorns are struggling in the Tetons, researchers spent two years tracking sheep and people throughout the range. While many factors contribute to their decline, the impact of backcountry skiing is significant. Sheep are sensitive to human activity, especially when they are confined to tiny, windswept alpine islands. When a skier comes into view, the sheep run, often through deep snow, sometimes for a long time, to find a new “island” with no sign of people. This skittishness consumes more energy than the sheep can afford. Combine this with the ever-present threat of avalanches, and many bighorns don’t survive the winter. 

As a conservation organization that speaks for the backcountry ski community, Winter Wildlands Alliance is uniquely positioned to advocate for winter wildlife conservation. We work with public land management policy experts who are well-versed in using policy tools to protect winter wildlife habitat from human impacts. We’re passionate about skiing, but we recognize that people are mobile and have a range of options of where to ski. Wildlife don’t have that same luxury. It’s our responsibility to ensure recreation doesn’t negatively impact wildlife.  

Protecting winter wildlife habitat has long been a conservation priority on both public and private lands because it’s critical to ensuring wildlife populations persist. A 2019 study in the northern Rockies found that both motorized and non-motorized winter recreation disturbs female wolverines, causing them to stop using areas within their home range where lots of recreation occurs. An animal’s home range is defined as the region that encompasses all the resources an animal requires to survive and reproduce. Home ranges are never bigger than what an animal truly requires, so anything that causes an animal to lose or stop using part of its home range is cause for concern.  

Photo: Josh Metten

Winter is a tough season for almost every critter, and animals are sensitive to human activities whether we’re on foot or astride a motor. Food is scarce. It takes a lot of energy to stay warm and move around. It’s also when many females are pregnant, and late winter and early spring is when many species give birth. As conservation-minded skiers who value wildlife, we have a responsibility to work with land managers and biologists to ensure that our recreation isn’t harming the wildlife we share the landscape with.  

The answers are still being developed. Right now, we’re working with land managers, other conservation groups, winter recreationists, and biologists to develop management recommendations that the Forest Service can use during winter travel planning to protect wolverines while continuing to provide winter recreation opportunities.  

Likewise, this winter in the Tetons, we’ll be working with skiers, biologists, land managers, and wildlife enthusiasts to find a way to protect the Teton bighorn sheep herd. If you would like to get involved or learn more, attend one of the collaborative meetings and help us figure out the best course forward for the sheep and skiers of the Teton range. The meetings will be in Jackson, Wyoming, on February 13 and 20, March 5th, and April 9.  

For more information, contact Hilary Eisen at Winter Wildlands Alliance or the Teton Bighorn Sheep Working Group at