Then and Now
Promulgated in 1999 in the wake of the bipartisan Grand Canyon Visibility Transport Commission’s recommendations, the Environmental Protection Agency (EPA) Regional Haze Rule established visual (instead of health-based) criteria for air quality to address declining visibility. The areas subject to this rule span the larger Class I national parks and wilderness areas (156 in total) overseen by the National Park Service, U.S. Fish and Wildlife Service, U.S. Forest Service, and several Native American Tribes.