The 1977 Clean Air Act set a national goal of cleaning up dirty air in major national parks and wilderness areas. Decades later, only a small handful of states have submitted legally required plans to comply. The result: power plant and factory emissions continue to obscure views of beloved landmarks in national parks across the country including Shenandoah, Great Smoky Mountains, Glacier, Big Bend, Acadia, Sequoia, and Yosemite.

On October 21, 2008, Earthjustice filed suit on behalf of Environmental Defense Fund and National Parks Conservation Association over the U.S. Environmental Protection Agency's failure to enforce deadlines for the states to adopt these clean air plans. The Clean Air Act required states to submit enforceable plans to EPA by last December to clean up hazy skies in parks and wilderness areas. As of June 2008, only six had submitted plans, according to EPA sources. The Earthjustice letter gave notice of intent to sue EPA unless the agency enforces the deadline against delinquent states within 60 days.

According to the National Park Service, human-caused air pollution reduces visibility in most national parks  throughout the country. Average visual range -- the farthest a person can see on a given day -- in most of the western United States is now about one-half to two-thirds of what it would be without man-made air pollution (about 140 miles). In most of the east, the average visual range is about one-fifth of what it would be under natural conditions (about 90 miles).

Earthjustice is suing EPA on behalf of conservation groups.