CHEYENNE -- The Wyoming Lodging and Restaurant Association is suing the federal government over rules that limit snowmobile use in Yellowstone National Park.

The group filed the U.S. District Court lawsuit Wednesday against the U.S. Department of the Interior, the National Park Service, Interior Secretary Gale Norton, and Park Service Director Fran Mainella.

The lawsuit came the same day the Park Service formally issued a temporary rule that would restrict the number of snowmobiles in the park to 720 a day, and all recreational snowmobile users in Yellowstone would have to travel with commercial guides.

The rule is to remain in effect through the 2006-07 winter.

The WLRA is challenging the legality of rule as well as the environmental assessment and "finding of no significant impact" that led to it. Environmental groups also have also sued to block the rule, the latest development in years of litigation over snowmobiles in Yellowstone.

Lodging and Restaurant Association Director Lynn Birleffi said the group hopes to eventually expand winter access to Yellowstone on behalf of its members as well as for the public in general.

"We believe citizens should have access to Yellowstone during its most spectacular time, and if we don't make sure that the snowmobiles don't have some role, then people just aren't going to be able to get into some parts of Yellowstone," she said.

She said restaurants and hotels in the region have suffered "because of the uncertainty on the part of the public about what's going to be available," and the association hopes the lawsuit will provide some stability in snowmobile use rules.

Business for some was down 50 percent last year, and it's even worse this year because of the snowmobile restrictions, Birleffi said.

The group argues that the government unlawfully failed to include a "no-action" alternative in its environmental assessment and failed to take a "hard look" at the environmental impacts of letting some people ride snowmobiles in the park without commercial guides.

Those actions violate the National Environmental Policy Act, according to the lawsuit.

The lawsuit also accuses the government of violating the federal Administrative Procedures Act by making an "arbitrary and capricious" decision.

"The federal defendants failed to provide a reasoned explanation for limiting the number of daily snowmobile entries into Yellowstone to no more than 720 snowmobiles per day," thus rendering the decision arbitrary and capricious, the group claims.

"We would like to see the daily limit a seasonal limit so that there's some flexibility between days," Birleffi said.

The WLRA wants a judge to nullify the temporary rule on winter use in the park and require the Park Service to go through the rule-making process again, only this time following the proper procedures.

In the meantime, the temporary rule would remain in effect.

Last week, several environmental groups sued Norton and Mainella over the snowmobile plan, claiming that the government failed to take into account the effect that roads groomed for snow machines have on wildlife, particularly bison, under the temporary plan.

The complaint brought by The Fund for Animals, Bluewater Network and three individuals was filed last week in U.S. District Court in Washington, D.C., after the Park Service issued a "finding of no significant impact" for its winter use plans, an attorney said.

The conservation groups are asking the judge to prevent officials from implementing the plan and to stop trail grooming "in some or all of" Yellowstone until there is compliance with such things as environmental laws and Park Service policies.

This comes despite Yellowstone's announcement earlier this year that an independent study was under way to look at the effect of groomed roads on bison movement in winter. Park officials had said that a final study report wouldn't be available for the environmental assessment process but that the issue would be addressed in a long-term analysis of winter use.

"The general rule is that, if you're not sure about the impact of something, you don't do it," said Howard Crystal, an attorney for the groups.

Birleffi said the state government will likely get involved in the litigation, as could other groups.

"I anticipate that there will be other intervenors," she said. "We'll see in the next couple days."

Capital bureau reporter Bill Luckett can be reached at (307) 632-1244 or at bill.luckett@casperstartribune.net.