Winter in Yellowstone: What Research Covers and What It Leaves Out

Yellowstone's winters have brought prolonged litigation and debate over snowmobiles, snowcoaches, air quality, wildlife and noise. A review of the research that debate produced finds it lopsided. Much of it asks visitors what they value and measures what vehicles do to wildlife and air; only one study included concessioner staff, and none looked at gateway communities, park staff or people who never visit. The article by Elise T. J. Gatti, Kelly S. Bricker and Matthew T. J. Brownlee summarizes a 2013 review by a University of Utah research team.

Why winter drew so much research

The first written accounts of winter trips into Yellowstone were by hunters in the late 19th century, who probably traveled on long wooden skis. Oversnow vehicles began with snowplanes in 1949, followed by snowcoaches and snowmobiles in the 1960s. They changed the park's infrastructure, patterns of use and the conditions visitors meet, and the social and economic fabric of the surrounding communities. Real and perceived effects on air quality, wildlife and the soundscape brought prolonged litigation and debate over the balance between recreational access, technology and resource protection. The park's first winter use plan was published in 1990, and every year the National Park Service fields requests from researchers who want to study winter use.

How the review worked

The authors asked what themes and gaps the literature shows on the "human dimensions" of winter recreation: the social attitudes, processes and behaviors around how stakeholders use the park, from individuals to society. Stakeholders are visitors, park staff, concessioner staff and people in the Greater Yellowstone Area.

They used a six-step, semi-inductive synthesis. They searched peer-reviewed journals, conference proceedings, government documents and technical reports from 1972, the park's centennial, to 2013, using databases, tips from Yellowstone staff and the bibliographies of what they found. They favored sources that had been heavily reviewed, and left out books, non-refereed periodicals, dissertations and theses. The 58 sources were 23 peer-reviewed articles, 28 government documents, five technical documents and two conference proceedings. Of the 30 research-based manuscripts, most dealt with the impact of recreation, especially motorized vehicles, on wildlife, air quality and the soundscape. The earliest source was a 1989 Department of the Interior background study for the first winter use plan, and sources from the 1990s were few, mostly about snowmobile impacts. Two papers, from 2002 and 1992, are called landmarks, each cited more than 100 times according to Google Scholar.

The authors say the review did not test hypotheses or use meta-analysis. A gap is a theme earlier authors or the team noticed that the reviewed literature had not scientifically explored; the list is not exhaustive, and they acknowledge possible subjective bias.

What was studied, and what was not

What the studies found

Visitors. Seven manuscripts, all from 2000 to 2013, looked at what visitors value. One study sorted winter visitors into four groups: naturalists, human oriented, players and park enthusiasts. Whatever their values, winter visitors named viewing scenery, wildlife and geothermal features as their main reason for coming, including those on snowmobiles, who see the machine as a means of viewing the park rather than a separate activity. The one study of concessioner staff found they felt visitors had shifted from using the park to experience snowmobiling to using snowmobiling to experience the park, and that visitors valued guided trips for the knowledge passed on through interpretation. These findings suggest that management should focus on the whole park experience rather than on single activities. Among the questions they raise: what do nonvisitors value, how attached are winter guides and park staff to the place, and how has local residents' use changed since commercial guide and best-available-technology rules for snowmobiles were introduced in 2004 and finalized in 2013?

Wildlife and the environment. Twenty-three manuscripts looked at the effects of recreation and transport on wildlife and environmental quality. Reported effects on wildlife include habituation to people, habitat disturbance, disrupted foraging and breeding, and stress responses in harsh winter conditions. How animals reacted depended on whether visitors stopped and approached, how long they stayed, how many vehicles there were, how near the animals were to the road and the size of the group. Studies of elk, bison and trumpeter swans reacting to oversnow vehicles found some effects, but 72% of the wildlife showed no visible response and less than 1% fled the area; commercial guides helped reduce effects by, for example, stopping at greater distances from animals and keeping people close to vehicles. Emissions fell greatly over time as the oversnow fleets changed models, engine sizes, cooling types and technology. Volatile organic compounds in surface runoff were within the limits set by the U.S. Environmental Protection Agency. Visitors to the Old Faithful area expect to hear natural sounds, and those on skis or snowshoes rated them more important than other groups did. The review found little research on grizzlies, wolves, bighorn sheep, mountain goats and mid-sized carnivores. Earlier researchers called for work on polycyclic aromatic hydrocarbons from engine emissions, which are harmful to human and animal health and persist longer than the compounds studied so far, and on vehicle fluids leaked onto snow roads, noting that all of Yellowstone's waterways are Class 1 Outstanding Natural Resource Waters.

Management. Sixteen manuscripts concerned policy and planning documents, many using Limits of Acceptable Change models and Recreation Opportunity Spectrum tools. No study evaluated how well the Recreation Opportunity Spectrum works for winter, or how well the public consultation methods used under the National Environmental Policy Act performed in Yellowstone.

The wider area. Eight manuscripts looked at Yellowstone and its surroundings: 20 counties in Idaho, Montana and Wyoming that are part of the 34,375-square-mile (89,031 square km) Greater Yellowstone Ecosystem. The most common question was the park's economic effect on nearby communities. Findings include that the park plays an important social and economic role regionally and nationally, and that its planning is politically charged, with substantial investment by national motorized recreation interests.

Methods. The review found little variety. Common approaches were measurements of air quality, water quality, exhaust emissions and sound levels, economic impact analyses, observer surveys of human-wildlife interactions, vehicle counts and visitor surveys. Radiotelemetry, benefit-cost analyses and measurements of wildlife stress hormones were rare.

Why it matters

The authors say systematic reviews like this let managers and researchers keep track of what is known about a park, and that the gaps can help Yellowstone and other parks with similar winter use.

Sources

• National Park Service, Human dimensions of winter use in Yellowstone National Park: A research gap analysis, by Elise T. J. Gatti, Kelly S. Bricker and Matthew T. J. Brownlee, summarizing a 2013 review by a University of Utah research team; rewritten in hubnx's own words.