The National Park Service has released a new policy that will regulate winter access to Yellowstone National Park by people riding on snowmobiles and snow coaches.
The policy released Tuesday takes effect starting in the winter of 2014-2015 and moves away from the current strict limits on daily numbers of snowmobiles in Yellowstone.
Instead, the new plan will regulate winter traffic through what's being called, "transportation events." They're defined as one snow coach or a group of up to 10 snowmobiles. Snowmobiles will be allowed to account for no more than 50 daily transportation events.
Then starting in 2015, snowmobiles in Yellowstone will need to have the best available pollution-control equipment and snow coaches must be fitted with the best pollution controls by 2016.