The National Park Service Organic Act and the Clean Air Act protect air resources in national parks, and in 2005, the National Park Service's Northern Colorado Plateau Network (NCPN) selected ozone, wet and dry deposition, and visibility as vital signs for long-term natural resources monitor-ing. Information relative to these three vital signs supports evaluation of compliance with legisla-tive requirements of the Clean Air Act's Regional Haze Guidelines and facilitates interpretation of plot-based vegetation and water-quality measurements. In 2010, the National Park Service's Air Resources Division published a nationwide report on air quality in national park units. This report expands on that information to provide a more comprehensive look at air quality in NCPN parks. Highlights from this report appear below.