[Off-road vehicles] are domineering, exclusive, destructive and costly; it is they and their operators who would deny the enjoyment of the backcountry to the rest of us. About 98% of the land surface of the contiguous USA already belongs to heavy metal and heavy equipment. Let us save the 2%--that saving remnant. --Edward Abbey

If future generations are to remember us with gratitude rather than contempt, we must leave them something more than the miracles of our technology. We must leave them a glimpse of the world as it was in the beginning, not just after we got through with it. --President Lyndon B. Johnson, upon signing the Wilderness Act of 1964

Snowmobiles were first allowed in Yellowstone National Park in 1963. Five years later, the National Park Service (NPS or Park Service), responding to growing public concern about the effects of snowmobiling on park resources, implemented the park's first official winter use policy. Winter use of the park, including snowmobiling, increased dramatically during the three decades following the Park Service's 1971 decision to groom snow-covered roads for passage by oversnow vehicles. Winter use doubled between 1983 and 1993, increasing from 40, winter visitors to 140,000. Today, there are over 180 miles of groomed trails within the park and, on peak days, as many as 1, snowmobiles entering. As the popularity of snowmobiling has increased, so has the snowmobiling public's desire for bigger, faster, and more powerful machines, and technology has evolved accordingly. This seemingly insatiable quest reflects the American public's general fascination with all things super-sized and motorized, and has created supersized noise and air pollution problems as well as significant threats to wildlife. As a result, Yellowstone has made the National Park Conservation Association's annual list of 10 Most Endangered National Parks every year since 1999 (the list is only six years old).