From the pages of
Sublette Examiner
Volume 2, Number 8 - May 23, 2002
brought to you online by Pinedale Online

Are Snowcoaches the Answer to Cleaner Air?
Snowcoach emissions are up to six times greater than new snowmobile engines.
by Kate Neely

A recent study shows surprising results that could lead to a shift in the promotion of the proposed ban of snowmobiles in Yellowstone National Park, according to a recent State of Wyoming press release. The study, conducted by the Southwest Research Institute (SRI) of San Antonio, Texas, shows snowcoach emissions to be as much as six times higher than the emissions produced by newly developed four-stroke snowmobile engines.

This recent study was one of six that was used to help prepare the Supplemental Environmental Impact Statement, which was created by the National Park Service (NPS) after the International Snowmobile Manufacturers Association filed a lawsuit in regard to the way the NPS was handling the snowmobile ban proposal.

Interestingly, this study marked the first time that snowcoach emissions have ever been measured, according to Kim Raap, manager of the Wyoming State Parks Trails Program. The SRI, whose Department of Emissions Research is one of the world's primary testing facilities, also developed the first test that ever measured emissions of snowmobiles. The recent study is especially significant, because in the past snowcoaches have been cited by environmentalists and people against the snowmobile ban as a cleaner and more efficient method of travel throughout Yellowstone. Snowmobiles have been criticized for their emissions levels by these same people. Now though, the proposed banning of snowmobiles to promote cleaner air can no longer be accurately supported by an alternative of restricting winter park travel to snowcoaches only. The results of this study prove another point: It is obvious that arguments promoting the snowmobile ban have not been accurate all along.

Why would people who are so concerned with the air quality of the park support snowcoach-only winter travel if emissions levels were high and damaging to the environment? If those who have been fighting for the ban on snowmobiles have been doing so strictly to support cleaner, purer air in the park, it makes sense, according to this study, to stop promoting the snowmobile ban and start promoting the use of new four-stroke engines.

Specifically, the study measured levels of carbon monoxide and hydrocarbons produced by four types of engines found in various modes of transportation. Here is exactly what the study had to say:

TransportationCarbon MonoxideHydrocarbon
(in grams per mile)(in grams per mile)
Snowcoach99.2 g/m1.63 g/m
Arctic Cat
4-stroke engine snowmobile
17.29 g/m1.60 g/m
Truck/van67.52 g/m5.85 g/m
Two-stroke engine snowmobile108.8 g/m39.89 g/m

After carbon monoxide and hydrocarbon levels had been measured with the various modes of transportation, results were compared not only between snowcoach emissions and four-stroke engine emissions, but also between four-stroke engine emissions and two-stroke engine emissions, as the chart signifies. The results showed an 84-percent decrease in carbon monoxide levels from the two-stroke to the four-stroke, and a 96-percent decrease in hydrocarbon levels from the two-stroke to the four-stroke.

Clearly, this chart supports the new four-stroke engine model, and that is encouraging for those who have been making such immense efforts to keep Yellowstone open to snowmobiles. In terms of transportation, "A total of five sleds would provide the same visitor transportation as one coach, but would have a total CO emission of 86.45 g/m compared to the one coach with emissions of 99.2 g/m," according to an online article.

According to the press release, the level of CO emissions released from snowcoaches is misrepresented in both the Winter Use Final Environmental Impact Statement and the Supplemental Environmental Impact Statement, as both documents include false statistics, stating the CO emissions as almost 50 percent below their actual level. In short, information and resources used to develop the EIS and SEIS are not accurate, because the creators neglected to use the best and most current technology, information and resources that are available.

A new hope is out there for snowmobilers and supporters who are battling to keep the park open to snowmobile travel. Thanks to time and setbacks that have occurred in the promotion of the ban proposal, this new cleaner and more efficient engine has been developed that passes emissions (not to mention noise) tests far better than original two-stroke engines and snowcoaches - and even automobiles. (If snowmobiles were banned, would the National Park Service see banning summer automobile travel through the park as a necessary next step to promoting cleaner air?) So for those who are against the snowmobile ban, this study reinforces the old-age saying: Never, never, never give up.

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