Air Monitoring History by Park

**The search function of this page is temporarily out of service - please look for a new and improved version later in 2019. In the meantime, you can learn about air quality monitoring in and around national parks by exploring the interactive map on our air quality monitoring home page.**

Since the late 1970's, the NPS has monitored visibility, gaseous pollutants (mainly ozone), and atmospheric deposition in parks around the country. Meteorological monitoring is also conducted at many locations to help interpret air pollutant levels. Monitoring networks that the NPS participates in include:

• Interagency Monitoring of Protected Visual Environments (IMPROVE)
• National Atmospheric Deposition Program/National Trends Network (NADP/NTN)
  • National Trends Network (NTN)
  • Mercury Deposition Network (MDN)
• Clean Air Status and Trends Network (CASTNet)
• Gaseous Pollutant and Meteorology Program (GPMP)

For additional information contact the Air Resources Division.