The state of Wyoming has asked a federal appeals court to give a judge authority to block a proposal reducing the number of snowmobiles allowed in Yellowstone National Park.

The National Park Service has said it intends to release a plan that could limit snowmobile traffic into Yellowstone and neighboring federal lands to 318 trips a day — less than half of last season's daily limit of 720.

The Wyoming Attorney General's Office argued Friday that the plan would violate U.S. District Judge Clarence Brimmer's order that set the daily limit at 720 snowmobiles a day.

A three-judge panel of the U.S. Court of Appeals in Denver heard arguments Friday in Laramie on an appeal by the National Parks Conservation Association, which wants Brimmer's order invalidated.

Snowmobile management issues in Yellowstone have been in turmoil over the last few years as federal courts in Wyoming and Washington, D.C. both have presided over lawsuits on the issue.

Conservation groups have sued seeking lower daily limits while Wyoming, Park County and snowmobile groups have pushed to maintain access.