Standing at the breath-challenging altitude of 9,680 feet in Rocky Mountain National Park, Yoram Hod is transfixed by the vista of the Continental Divide. "It's beautiful," he says with genuine awe.
"But so much smog!" he laments, turning to his wife, Yael.
The Hods, here from Israel on vacation, say they are surprised to see this filmy haze in such a pristine place. "The air is much cleaner in Israel," says Mr. Hod, a mechanical engineer visiting America for the first time. "They should protect parks like this - and if it means new laws, then so be it."
The words could easily have been spoken by an official from the US Environmental Protection Agency. The EPA recently proposed regulations to help clear the air - literally - in more than 150 national park and wilderness areas across the country, including Grand Canyon, Yellowstone, Big Bend, and Yosemite.
The proposed "regional haze regulations" mark the first time in history the government has attempted to reduce air pollution purely for aesthetic reasons. It also represents an unusual effort to control pollutants that drift hundreds of miles across state borders, setting up a clash between environmentalists and industry. "In effect, it's a federal law that requires pristine air," says Vaughn Whatley, an EPA spokesman in Denver. "The new rules are trying to address haze on a regional basis."
The proposal, which calls for a 10 percent improvement in visibility every 10 to 15 years during the next century, is a landmark attempt to reverse the downward trend of air quality in national parks. The regulations target industrial manufacturing and power plants by imposing strict emissions standards. They also require states to work collectively to reduce regional pollution.
A public comment period on the proposed regulations continues until Oct. 20. National parks advocates have been cheering the move. Industry has not. In February, the EPA will issue its final rule on the plan, which, if approved, would take effect in 1999.
Haze, produced by fine particles in the air, is generally the product of many pollutants. Because particles travel hundreds of miles, haze tends to occur regionally. Smog, by contrast, is generally polluted air from local sources that stagnate over an area.
HAZE in the Rockies is typically from a mix of sources: freeways in Los Angeles and Denver, emissions from smelters and refineries in the Southwest, manufacturing in Mexico, regional forest fires and backyard barbecues, and even dust kicked up from unpaved roads.
On a bad day at the Grand Canyon, visitors on the south side of the canyon can barely see the North Rim, just 10 miles away. (On a good day visibility extends 100 or more miles.) Air experts also say Sequoia National Park, at the base of the Central Valley - where particulates pool by virtue of topography - is the second-most air-polluted place in California. Only L.A. is worse.
In the Rocky Mountains, it was once possible to find 150-mile vistas. Now average visibility is 30 to 90 miles. Nor are these the only areas coping with obscured views. "We find air-pollution problems in every park around the country," says Chris Shaver, air-quality chief for the National Park Service.
Air pollution in the interior West isn't necessarily worse than elsewhere, just more visible. That's because high elevations and dry air make even a small amount of pollution apparent. Mountain valleys also act as collection traps for westward flowing pollutants in Yellowstone, the Grand Tetons, and Canyonlands. "We've been waiting for 20 years for the EPA to come up with a proposal," says Jim Martin of the Environmental Defense Fund in Boulder, Colo.
Opponents of the plan, however, point out that regional haze results from a combination of pollutants. Therefore, they maintain, keeping the focus on "stationary sources" - refineries, power plants, and steel mills - will barely improve visibility.
"The way they're writing this, there's going to be no benefit," says Dennis Arfmann, a Denver attorney representing the Colorado Association of Commerce & Industry. "This won't get us where we want to go."
But air-quality experts believe cleaning up industry emissions will help clear the air. In the West alone, power plants put out 50,000 tons of pollutants annually, says Ms. Shaver.
Motor vehicles do contribute to dirty air, but not much more can be done to clean up emissions, Shaver says - short of switching to electric or solar-powered cars.
Yet as population centers and the pollution of daily life inch closer to national parks, haze is likely to become more visible. Denver, for example, less than 100 miles from Rocky Mountain Park, continues to grow rapidly. "Rocky Mountain is one park that's a bit frightening from our perspective because it's downwind from a growing area," says Shaver.
The pollution is apparent to Kansans Ron and Diana Coad, who are on their first visit to Rocky Mountain. "We're used to clear skies in Kansas," says Mrs. Coad. "We do notice the haze." Even so, she says taking in the serrated cap of the Rockies, "It is still pretty."