The state of Wyoming and one of its counties are seeking an avenue to sue the federal government over the reduced number of snowmobiles allowed in Yellowstone National Park on a daily basis.

Although only a fraction of the snowmobile traffic that enters Yellowstone National Park comes in through the park's East Entrance, the Wyoming county that is the gateway to that entrance has sued the National Park Service over limits on how many snowmobiles can enter the park.

As expected, National Park Service officials Thursday approved a winter-use plan for Yellowstone and Grand Teton national parks that reduces snowmobile numbers in Yellowstone from past years. The intent is that this plan remain in effect for two winters while Park Service teams develop yet another environmental impact statement on winter recreation in Yellowstone.

While there are many, many more cars, trucks, and motorcycles traveling through Yellowstone National Park in summer than snowmobiles in winter, the summer traffic is not quite as polluting, according to park studies. Indeed, a greater problem with air quality in summer stems from forest fires.