Washington, DC – A judge ordered the National Park Service Tuesday to explain why it should not be held in contempt, for allowing more snowmobiles into Yellowstone and Grand Teton national parks than allowed under his December ruling. US District Judge Emmet Sullivan in Washington DC scheduled a contempt hearing for March 9th. In December, Sullivan ordered that only 493 snowmobiles be allowed in the park per day. The Park Service last Wednesday began allowing 780 snowmobiles per day to enter Yellowstone. The agency is relying on a recent order by a Wyoming federal judge, who issued a temporary restraining setting aside a ban on snowmobiling in the parks.