Protecting Public Health and the Environment.

Visibility and Haze

Haze is one of the most basic forms of air pollution and degrades visibility in many American cities and scenic areas. It is caused when sunlight encounters pollution particles in the air, which reduce the clarity and color of what we see.

Haze pollution can come from a variety of natural and human-made sources. Natural sources can include windblown dust and soot from wildfires, and human-made sources can include motor vehicles, electric utility and industrial fuel burning, and manufacturing operations. Particulate matter pollution is the major cause of reduced visibility (haze) in parts of the United States, including many of our national parks.

Idaho and other states have been working with the Environmental Protection Agency to protect visibility at certain national parks and other scenic areas. Idaho has focused on Craters of the Moon National Monument, the Sawtooth Wilderness, and the Selway-Bitterroot Wilderness Area.

Idaho developed a plan in 2010 to address haze pollution and will submit an additional plan in 2021. As the plan progresses this site will be updated as needed.


Staff Contacts

Airshed Management Analyst
Pascale Warren
DEQ State Office
Air Quality Division
1410 N. Hilton
Boise, ID 83706
(208) 373-0586

DEQ Resource

Idaho Regional Haze Plan (October 2010)

More Information

EPA Visibility and Regional Haze Webpage