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Visibility in Parks and Wilderness Areas

Since 1988, the EPA, States, and Federal land management agencies have conducted monitoring of air pollution and visibility impairment at a number of national parks and wilderness areas across the United States.

IMPROVE Visibility Monitoring Network - Access IMPROVE monitoring data resources and educational material on the science of visibility and regulations.
Visibility Trends in Class I Areas - Access summary graphs of visibility ("Visibility" under "AQRV Summaries") in Class I areas.
Visibility Report to Congress
National Air Quality Trends

Visibility in Parks and Wilderness Areas

Visibility and Haze