National Park Service studies have shown that allowing 250 snowmobiles a day into Yellowstone National Park causes ecosystem damage and noise pollution. So with new rules effective starting winter 2008, the agency logically will allow 540 snowmobiles a day into the park, down from an original suggestion of 720. The NPS followed through on its intention to disregard public opinion, which strongly favored a snowmobile-free park.

Grist thanks its sponsors. Become one.