• Steam rises off of the colorful Mammoth Hot Springs Terraces. Photo courtesy Jacob W. Frank


    National Park ID,MT,WY

Final Winter Use Rule for Yellowstone and Grand Teton Published in Federal Register

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Date: December 13, 2007
Contact: Yellowstone: Al Nash / Stacy Vallie, (307) 344-2015
Contact: Grand Teton: Jackie Skaggs, (307) 739-3393

Parks set to open for the winter as scheduled on Wednesday


The final rule implementing the Record of Decision on a long-term plan to guide management of winter use in Yellowstone and Grand Teton National Parks and the John D. Rockefeller, Jr. Memorial Parkway was published in the Federal Register today.  


The rule becomes effective on Wednesday, December 19, 2007, allowing the parks to open for the winter 2007-2008 season on that day as scheduled. 


The rule calls for changes in winter use in the parks beginning with the 2008-2009 winter season. The rule calls for operations to continue this winter essentially as they have the past three winters.


Starting with the winter of 2008-2009, five hundred forty (540) Best Available Technology (BAT) snowmobiles and eighty-three (83) snowcoaches will be allowed per day in Yellowstone. All snowmobiles and snowcoaches will continue to be 100% commercially guided. The rule continues to require that snowmobiles and snowcoaches travel only on existing park roads groomed for their use. Trail and off-road use of snowmobiles and snowcoaches has always been, and will continue to be, prohibited.


In Grand Teton and the Parkway, grooming and motorized oversnow travel on the Continental Divide Snowmobile Trail (CDST) between Moran Junction and Flagg Ranch will be discontinued. Twenty-five (25) snowmobiles a day will be allowed to travel on the Grassy Lake Road, with no BAT or guiding requirement. Forty (40) unguided, BAT snowmobiles a day will be allowed on Jackson Lake to facilitate ice fishing by those possessing appropriate fishing gear and a valid State of Wyoming fishing license. 


Beginning with the 2008-2009 winter season, the rule provides for snowmobile and snowcoach travel over Sylvan Pass when full avalanche forecasting, as defined in the Operational Risk Management Assessment, indicates travel through the pass is safe. The pass will be closed to all travel when such forecasting shows travel is unsafe, and will reopen to travel only when forecasting indicates the danger has subsided. However, the National Park Service will work with the State of Wyoming, Park County, Wyoming, and the City of Cody to seek a consensus approach to avalanche mitigation by June 1, 2008, to provide alternate ways for safe motorized oversnow access over Sylvan Pass.


Beginning with the 2011-2012 season, all snowcoaches operating in the parks will be required to meet emission and sound level requirements. These requirements, like those for snowmobiles, are intended to further improve air quality and soundscape protection.


In Yellowstone this winter (2007-2008), up to 720 commercially guided Best Available Technology (BAT) snowmobiles a day will be allowed to enter the park.

The rule calls for Sylvan Pass to remain open to motorized oversnow travel. Yellowstone will use a combined helicopter and howitzer program to conduct avalanche hazard mitigation operations this winter.  Methods used to reduce the risk of avalanche hazard mitigation this winter may result in longer temporary closures between the detection of avalanche risk and the reopening of Sylvan Pass to motorized oversnow travel compared to historic avalanche hazard mitigation operations.


In Grand Teton and the Parkway, 140 snowmobiles a day will be allowed this winter. Most of the snowmobiles will have to meet BAT requirements. Access to the Continental Divide Snowmobile Trail, Grassy Lake Road, Jackson Lake, and adjacent public and private lands will continue like they have the past three winters.


The Final Rule implementing the Record of Decision can be found on the web at



The Record of Decision and the Winter Use Plans Final Environmental Impact Statement can be found at the National Park Service’s Planning, Environment and Public Comment (PEPC) website at http://parkplanning.nps.gov/documentsList.cfm?parkId=111&projectId=12047


Copies of all these documents are available in hard copy by writing the Winter Use Planning Team, P.O. Box 168, Yellowstone National Park, Wyoming 82190. Document requests may also be made by sending an e-mail to yell_winter_use@nps.gov; by calling 307-344-2019 during normal business hours; or by sending a request by fax to 307-344-2025.


- www.nps.gov -


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