Yellowstone Milestones

1872
Congress sets aside more than 2 million acres in the northwest corner of Wyoming as Yellowstone National Park.
1963
Recreational snowmobiling in Yellowstone begins.
1983-1993
Fueled by the growing popularity of snowmobiles, the number of winter visitors doubles in 10 years, from 70,000 in 1983 to more than 140,000 in 1993.
Winter of 1996-1997
More than 1,000 bison leave the park, some along groomed trails, and are killed in order to protect local livestock.
May 1997
The legal battle over snowmobiles in Yellowstone begins. The Fund for Animals sues the National Park Service, alleging the activity violates laws governing park management.
October 2000
The Park Service's final environmental impact statement mandates a phase-out of snowmobiles and a complete ban by 2004 .
Jan. 22, 2001
The Park Service publishes the "snowcoach rule," which eliminates snowmobiles in favor of the larger, bus-like vehicles for winter touring. The rule does not address trail grooming.
Jan. 31, 2001
The Bush administration puts a stay on the snowcoach rule.
June 2001
Park Service settles a lawsuit by snowmobile manufacturers and other advocates. It agrees to consider data about new snowmobile technologies in a supplemental impact statement.
March 25, 2003
A decision allows 950 snow-mobiles to enter Yellowstone and Grand Teton national parks daily. Snowmobiles must meet noise and emissions standards.
Dec. 16, 2003
Federal District Court Judge Emmett G. Sullivan of the District of Columbia overturns the 2003 rule. He reinstates the snowcoach rule, beginning a phase-out that year.
Oct. 15, 2004
Federal District Court Judge Clarence Brimmer rejects the snowcoach rule as a "prejudged political decision" by the Clinton administration.
November 2004
The Park Service issues a temporary winter use rule for limited snowmobile use while it conducts further study and monitoring.

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