December 21, 2014 - Press Release - YELLOWSTONE OPENS FOR SNOWMOBILES. 
Yellowstone National Park has opened for snowmobiles and other motorized snow machines even if recent warm weather and limited snowfall means there's little snowpack on many of the park's interior roads.
Until conditions improve, visitors will be allowed to take snowmobile trips or travel by commercial snowcoach between the park's South Entrance and Old Faithful. Other trips involving commercial snowcoaches and other vehicles will be available in other limited sections of the park.