DENIZENS OF THE STEEP
Denizens of the Steep follows world-renowned ski mountaineer, Kim Havell, as she explores and redefines what it means to be a backcountry skier. In her 25 years as an extreme skier, Kim has seen the sport evolve at a breakneck pace. She knows that we face an uncomfortable truth: as outdoor recreation continues to explode in popularity, the conservation of our most cherished wild places will face new and unprecedented challenges. Through the eyes of Kim and her family, we learn that the backcountry code of ethics must be rewritten: cause no unnecessary harm. Leave only ski tracks. The secret is out. Backcountry skiing is %#ing awesome.
For thousands of years, Wyoming’s Teton Range has been home to a band of rugged mountain athletes. The Teton Bighorn Sheep herd has watched as neighboring herds went extinct in the nearby Bighole and Snake River Ranges. Yet they have persisted against the odds, enduring blizzards, avalanches, subzero temperatures and gale force winds atop ridgelines high in the Teton Range. The herd is now on the brink of extinction. Habitat destruction, lost migration routes, and invasive species have reduced the herd to fewer than 100 individuals.
FACTS ABOUT THE PROJECT
HOW MANY BIGHORN SHEEP ARE LEFT IN THE TETON HERD?
For many years, the Teton Range bighorn sheep population was estimated at 100-125 individuals. However, fewer than 60 sheep were counted during the three most recent helicopter surveys, and the population is currently estimated at only about 80 individuals.
WHAT MAKES THE TETON HERD UNIQUE?
A small, isolated population of bighorn sheep resides in the Teton Range. The population is further subdivided into two groups, at the north and south ends of the range, with little interchange. This population is considered a core, native herd by the State of Wyoming, meaning it has not been extirpated and repopulated with transplanted sheep. The population is of high conservation value because of its unique and irreplaceable genetics. Additionally, the small size of the population puts it at increased risk of local extinction due to chance events (e.g. winters of high avalanche activity, disease, etc.) and poor genetic resilience. The population no longer has access to its historical, low elevation winter ranges (Whitfield 1983) because of human influence (e.g. development, fire suppression, disturbance, etc.).
WHAT ARE THE PRIMARY THREATS TO THE SURVIVAL OF THIS POPULATION?
The population is currently facing multiple environmental stressors that threaten its long-term survival, including the loss of crucial winter range due to recreational (skier and snowmobile) disturbance and long-term fire suppression, threats of new diseases and possible competition related to an expanding nonnative mountain goat population, and reduced genetic diversity owing to a small population size and isolation from other populations.
HOW DOES BACKCOUNTRY SKIING DISTURB SHEEP?
Backcountry skiing, snowboarding, and mountaineering are popular winter pursuits in the Teton Range. Winter visitor numbers in the Tetons and the spatial extent of their footprint has increased dramatically during the last decade. Human activity now frequently extends into habitats that are critical to wintering bighorn sheep.During winter, the sheep live along the crest of the Tetons, eking out a living on windswept ridges above 8,500 feet. Winter conditions in these locations are often extreme due to high winds, low temperatures, deep snow, and limited forage; and predispose the sheep to avalanches, falls from cliffs, or poor nutrition. Mortality to Teton bighorn sheep from these causes is typically greater than in sheep populations that use low elevation winter ranges. Winter is a difficult time for bighorn sheep because they live off their fat reserves built up during the summer. Energy expenditures resulting from recreational disturbance can cause sheep to burn unnecessary calories that could compromise their ability to survive and reproduce. Recent research aimed at understanding the effects of winter recreation on bighorn sheep (Courtemanch 2014) found that: sheep avoided backcountry skiing areas, even if those areas were otherwise good habitat (and connected to habitat that sheep were using). In some cases, sheep were effectively losing up to 30% of the available habitat in their home range because of displacement by skiers. Sheep wintering in areas with high backcountry skiing activity had higher daily movement rates than sheep in areas with lower skier use, which translates into unnecessary expenditure of calories and may result in reduced reproductive success and overwinter survival.