Stop Bombing Avalanche Paths at Yellowstone Pass, Groups Argue

sylvan pass yellowstone national park snow removalYELLOWSTONE NATIONAL PARK’S Sylvan Pass receives little more than one snowmobiler a day during winter, yet the National Park Service spends $325,000 a season for avalanche control on it, and a coalition of groups is arguing that the practice should be stopped — as the park’s own staff recommended in 2007.

The Coalition of National Park Service Retirees, backed by several other conservation groups, has strongly criticized Yellowstone National Park’s winter use plan to keep Sylvan Pass open between Cody and the park’s east entrance. The pass features 20 avalanche runs that must be knocked down by artillery shells fired from a 105mm howitzer. Weather permitting, high explosives are hand-dropped on the avalanche runs from a helicopter.

In recent years, only a handful of winter tourists a week have ventured through the pass into the remote reaches of East Yellowstone. The coalition objects not only to the low cost/benefit ratio, but also to the risk to park employees traveling past four avalanche runs to reach the howitzer gun site, which itself is exposed to avalanche and rock fall.

The death of park ranger Bob Mahn in 1994, east of Sylvan Pass, is as an indicator of the risks faced by park staff each winter under the avalanche runs, the coalition claims.

In separate letters to Yellowstone Superintendent Daniel N. Wenk and the Office of Management and Budget (the watchdog arm of the White House), the coalition and its allies noted, “Sylvan Pass is the only location in the entire National Park System where the NPS undertakes highly expensive and highly risky winter avalanche mitigation operations solely to permit recreational use…averaging little more than one snowmobile per day.” 

Although state transportation departments and ski areas on federal lands in the Rockies use howitzers to shoot down avalanches, Sylvan Pass is the only NPS operation to do so, leaving other avalanche-prone areas closed to the public.

The coalition has also expressed concern about unexploded shells – one of which was picked up in 1997 and carried by a tourist to the Fishing Bridge Visitor Center.

The letter to the Yellowstone superintendent came from the Coalition of National Park Service Retirees, the National Parks Conservation Association, the Sierra Club, and the Natural Resources Defense Council. The letter to OMB came from those groups plus the Greater Yellowstone Coalition.

Don Bachman, president of the board of directors for the Center for Snow and Avalanche Studies, opposes keeping Sylvan Pass open in the winter, and offered written comments on the NPS plan in 2007. Should anything go wrong for avalanche gunners or subsequent tourists, he noted, rescue and medical help from the Wyoming towns of Lake or Cody would take hours to reach Sylvan Pass in bad weather.
Bachman, who has 40 years of experience in the Rockies and Alaska, studied the situation for Yellowstone and found it to be unique in his experience.

Fewer winter visitors in recent years mean a lower probability of anyone getting caught in an avalanche, he said. Increasing the number of visitors would simply increase the odds of such an accident occurring.
“But that’s balanced out by a high density of avalanche paths within one mile,” he added. While the low number of winter tourists means lower odds for tragedy, the high number of runs in one area means higher odds.

“You’re playing the odds,” he said, “and the Park Service is trying to improve the odds with avalanches on demand.”

The closest situation Bachman has seen to Sylvan Pass was when Glacier National Park officials refused permission in 2008 to Burlington Northern Railroad management to use explosives on park land for avalanche control. The railroad then switched from its strategic use of explosives, adopting instead prediction of avalanches coupled with adjustment of freight schedules.

Bachman said the railroad had much more money at stake than Cody’s snowmobile access to Yellowstone, even if winter snowmobile activity were to rise back into the thousands. “As far as I can tell, this was a political decision,” he said.

He called the decision to keep the Sylvan Pass open “completely discretionary.”

Feeling overwhelmed by snowmobiles, Yellowstone staff launched a winter use plan at the end of the Clinton administration, which eventually led to a ban of the machines from the park. The incoming Bush administration quickly rolled back the ban, and instituted a series of winter use studies—all of which said park resources were best protected by a ban on snowmobiles.

Caps were placed on how many snowmobiles and coaches could enter the park per day, and best-available-technology standards were adopted to decrease the noise and emissions of over-the-snow vehicles. As a way to increase safety and decrease the harassment of wildlife, guides were required for anyone entering the park.
Subsequently, the experience of snowmobiling in Yellowstone shifted away from thrill-oriented rides to cruises and sight-seeing, which more closely echoed what the snowcoaches were already offering.
The light, fast, noisy and smoky two-stroke snowmobiles were replaced by heavier, quieter and cleaner four-stroke snowmobiles, derisively dubbed “granny sleds.” Winter visitation numbers by snowmobilers steadily fell, while snowcoach passenger numbers rose.

The East Gate had 3,160 snowmobilers in 1996, a heyday that peaked in the winter of 2000-2001 with 4,183 snowmobilers. A historic low of 92 was reached by 2009, rising slightly to 168 last winter.
Snowcoaches from Cody brought 250 tourists into the park during the winter of 2007-’08, but that service has not operated for the last three seasons. For the past several years, the town has had only one snowmobile vendor.

Coalition members point out that Cody’s hotel tax revenues are up despite the snowmobiling downturn at the park. Figures from the Wyoming Department of Revenue show that Park County’s lodging tax collections for the last five winter seasons increased from $80,364 in 2006-2007 to $103,459 in 2010-2011.
During that same period, the number of snowmobiles entering Yellowstone through the East Entrance declined from 209 to 115 per season. Snowmobilers seem to have shifted their attention from Yellowstone to the numerous trails in the nearby national forests, where two-stroke snowmobiles are still welcome, the coalition argues.

“The National Park Service’s 2009 winter use plans have displaced snowmobiles from Yellowstone National Park, Grand Teton National Park, and the John D. Rockefeller, Jr. Memorial Parkway onto adjacent national forest lands in Wyoming,” according Bradley Hill, trails program manager in Wyoming’s Department of Parks and Cultural Resources.

Yellowstone’s most recent environmental impact statement, released a couple months ago, reached the same conclusion as its predecessor of two years earlier concerning Sylvan Pass: Risks could not be fully mitigated and closure of the pass was viewed as the safest option.

Even so, Yellowstone officials have opted for keeping Sylvan Pass open. This contrasts to a 2007 decision by Yellowstone officials to close the pass because of accident risk and budget concerns.

This environmental coverage made possible in part by support from Patagonia. For information on Patagonia and its environmental efforts, visit In affiliation with New West. Photos via National Park Service.

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