Taking the Long View: Clean Air, Clear Views

Left image
Clear view, 107 mi (173 km). NPS Webcam Photo; March 3, 2018
Credit: NPS Webcam

Right image
Hazy view, 40 mi (65 km). NPS Webcam Photo; May 2, 2018
Credit: NPS Webcam

Slide the bar on the image above to see the difference that haze makes to this Shenandoah National Park view of Virginia's Luray valley and Appalachian mountains. Visit the air webcam page to see how this view looks today and explore more air webcams.

On very clear days, we can see the bright, crisp colors and textures of national park landscapes highlighting the spectacular natural and historic settings that define these special places. Distant features appear on the horizon, and even in places without distant features, vibrant blue skies and bright white clouds with sharp edges can be seen on clear days. Air pollution can create a haze that dulls these scenes by softening the textures, fading colors, and obscuring distant features.

For example, Shenandoah National Park in Virginia has more than a million visitors each year. Over the past few decades, the average distance Shenandoah National Park visitors can see has improved dramatically, from 35 miles in 1990 to 80 miles in 2018.

Credit for this improvement goes largely to the US Clean Air Act amendments of 1977 along with improvements by industry in air pollution control technology. Still, it is important to remember that without any air pollution, average visibility at Shenandoah National Park would be 121 miles. So, we still have a long way to go.

Similar improvements in visibility are happening in national parks across the country and there is more that needs to be done to protect America’s magnificent views and scenic vistas from pollution. The National Park Service is committed to understanding and protecting air in parks. Learn more about how haze affects how well and far we can see (visibility) as well as how the NPS monitors air pollution in parks. Explore how air quality has changed over time at your favorite park by visiting our conditions and trends page.