A Park Service plan for snowmobiles in Yellowstone that keeps 720 snowmobiles per day and closes Sylvan Pass disappointed both conservation groups and pro-snowmobile groups.

Conservation groups said the plan is ignoring numerous scientific studies that say a snow-coach-only alternative is best for the park’s air quality, noise level and wildlife.

And snowmobilers expressed displeasure that the National Park Service’s preferred plan doesn’t include an option for certified, noncommercial guides to lead tours through the park and closes Sylvan Pass.

“I’m disappointed that our efforts ... to get unguided access into the park didn’t show up in the draft,” Blue Ribbon Coalition President Jack Welch said. “Every cooperating agency that was appropriate, all of them were in favor of that in their comments.”

Perhaps a bigger disappointment for snowmobilers and businesses in the Cody area is the decision to close Sylvan Pass. Park Service officials say the pass is not only problematic because of avalanche danger, but also expensive to maintain for the small number of visitors who actually use the road.

Terry Hinkle, a Cody resident and spokesman for the group Shut Out of Yellowstone, said the park is ignoring the public by deciding to close the East Entrance to snowmobiles. At a meeting last week, between 500 and 700 people met with Yellowstone Superintendent Suzanne Lewis in an effort to keep the pass open.

“We certainly disagree with that decision and we are going to continue our fight to keep the east gate open to all public access,” Hinkle said. “There are a lot of businesses ... in the town of Cody and the county of Park County that are going to suffer as a result of this closure. We have a limited tourist season as it is.”

Hinkle said a Park Service study questioned whether Yellowstone officials could open the east gate quickly each spring if there were no avalanche control.

“[The study] concludes that without active avalanche control, it may delay the opening of the east gate,” Hinkle said. “It may be a nine-month closure. That would probably wipe out the town of Cody.”

Park officials were quick to emphasize that the proposed plan, contained in an environmental impact statement released Tuesday, is not necessarily the one park officials will pick when the final decision is made next fall.

Bill Wade, chairman of the executive council of Public Employees for Environmental Responsibility, hopes it won’t be. He said the Park Service decision caters to snowmobile groups.

“It seems like what they’re trying to do is satisfy a relatively narrow range of public interests,” he said. “That just continues to be bewildering to us.”

“Four out of five people in the past EIS comments have expressed the preference for no snowmobiles, yet snowmobiles still play a prominent role in the current EIS,” Wade said.

Environmentalists point to sections of the environmental impact statement itself that show consequences to air quality and noise levels should the Park Service choose to allow 720 snowmobiles per day, compared with a snow-coach-only alternative.

For instance, carbon monoxide emissions would be nearly five times greater with the snowmobiles, while hydrocarbon emissions would be 17 times greater.

“Every previous study has concluded that snow coaches are best for the park,” said Amy McNamara, national parks program director for the Greater Yellowstone Coalition. “We’ve been looking at this for 10 years now. It’s time the Park Service upholds its policies, heeds the science and respects the public who, by a 4-to-1 margin, wants the best possible protection for Yellowstone.”

Eleven former Interior Department employees, including seven former Park Service directors, also urged the ban of snowmobiles in Yellowstone in a letter Monday to Interior Secretary Dirk Kempthorne.

The EIS concluded that the “environmentally preferred alternative” for Yellowstone would be no snowmobiles at all. But Superintendent Lewis said that does not meet other Park Service priorities, such as allowing public access.

“The environment in which we live in and manage the park within is much broader than the confines of an environmentally preferable alternative,” she said.

The Park Service’s snowmobile proposal is essentially the same as a draft put forth late last fall.

In addition to requiring snowmobilers to use a commercial guide, it mandates that machines be equipped with the “best available technology,” namely four-stroke engines that are considered quieter and less polluting than traditional two-stroke machines. Further, it would limit the number of snow coaches to 78 per day.

According to John Sacklin, management assistant for Yellowstone, changes in the new environmental impact statement include language that allows skiing and snowshoeing six to nine miles inside the East Entrance of Yellowstone, despite the closure of Sylvan Pass.

The new draft would also require snow coaches to use the best available technology. Sacklin said the historic Bombardier snow coaches used in Yellowstone could be upgraded with modern engines and transmissions.

“We think it’s high time to get the more-polluting snow coaches off the snow,” he said.