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Safeguarding Yellowstone National Park from Snowmobiles

Snowmobilers drive near bison in Yellowstone National Park.

Snowmobilers drive near bison in Yellowstone National Park.

Jim Peaco / National Park Service

What’s at Stake

Recreational snowmobiling brings with it adverse air, noise, and wildlife impacts. The Park Service's biologists had concluded that lower vehicle numbers were necessary to protect the park's winter-stressed wildlife.


For eight years, the Bush administration worked to reverse the National Park Service's 2001 decision to eliminate recreational snowmobiling—and its adverse air, noise, and wildlife impacts—from Yellowstone National Park. In 2003, Earthjustice attorneys succeeded in overturning in court the Bush administration's first Yellowstone snowmobile plan, under which 950 snowmobiles would have been allowed into the park each winter day. In 2007, the Bush administration finalized a second plan authorizing 540 snowmobiles in Yellowstone each winter day—twice the number of recent winter seasons, during which the Park Service's own noise and air quality thresholds were violated by snowmobiles. The Bush administration's plan to double the number of snowmobiles within Yellowstone contradicted the recommendation of Park Service's own biologists, who had concluded that lower vehicle numbers were necessary to protect the park's winter-stressed wildlife.

On September 15, 2008, a federal court in Washington, D.C., rejected the Bush administration's 540-snowmobile plan in a second Earthjustice lawsuit, reaffirming that "the fundamental purpose of the national park system is to conserve park resources and values." In the words of the court, the administration's decision to allow a doubling of snowmobile use within Yellowstone "clearly elevate[d] use over conservation of park resources and values" contrary to Park Service mandates. The court set aside the Bush administration's plan and directed the Park Service to develop a new regulation protective of Yellowstone National Park.

The Bush administration refused. Citing a November 2008 Wyoming court decision that left the Park Service with the authority to develop a new winter use plan, in December 2008 the Bush administration published a regulation that will allow 720 snowmobiles into the park each winter day—180 more than the plan invalidated only three months before by the Washington, D.C., court. Earthjustice filed a lawsuit on behalf of five conservation groups challenging the Bush administration's eleventh-hour effort to perpetuate recreational snowmobiling within Yellowstone National Park.

In 2009, the National Park Service announced it will restrict snowmobile numbers in Yellowstone National Park to less than half of the previous winter's limit, a move that will reduce the impact of the machines on the park's air, wildlife, and natural quiet. The decision will undo the eleventh-hour Bush administration rule.

Case Updates

January 10, 2006 | Legal Document

Yellowstone Snowmobiles Opinion

Strikes down a plan by the Bush administration to allow nearly 1,000 snowmobiles to enter Yellowstone and Grand Teton National Parks each day (December 16, 2003)