A federal judge on Friday struck down a ban on snowmobiles (search) in Yellowstone (search) and Grand Teton (search) national parks, calling it a "prejudged, political" move that sought to exclude the vehicles from all national parks.

U.S. District Judge Clarence Brimmer ruled that the Clinton-era ban was invalid because it did not involve adequate public participation and failed to follow federal law. His decision could clear the way for new rules that allow the machines.

The rule was "the product of a prejudged, political decision to ban snowmobilesset to take effect last winter, was set aside in early 2003 by the park service to settle a lawsuit filed by snowmobile makers. Under the agreement, new rules were drafted to allow a limited number of snowmobiles inside the parks.

Attorneys for snowmobile manufacturers, winter resorts and other tourism-related ventures asked a federal judge last month to permanently lift the ban so businesses could have peace of mind about their survival.