Mount Rainier National Park is located downwind of a number of urban and industrial areas to the northwest and southwest and is not isolated from the by-products of industrialization. Manmade air pollutants are transported long distances and have been detected through air quality monitoring programs. A number of stationary and mobile sources of pollutants affecting the park include a variety of sources in the Puget Sound region as far north as Vancouver, and as far south as Portland, Oregon. Pollutants traveling across the Pacific Ocean from Asia, and including pollutants from Europe and eastern North America that circumnavigate the globe, are deposited in lakes, streams and on land within the Cascade mountain range at high elevations. National parks over 6,000 acres and national wilderness areas over 5,000 acres that were in existence before August 1977, are designated as Class I areas.
Mount Rainier National Park and some of the surrounding U.S. Forest Service wilderness areas are Class I areas. Areas designated as Class I receive the highest level of air-quality protection. Consequently, Mount Rainier National Park staff are very involved in the National Park Service's comprehensive air resources management program, designed to assess air pollution impacts and protect air quality related values. Air quality related values include scenic vistas, sensitive natural ecosystem processes, functions and components and cultural resources, The air resources management program at Mount Rainier includes monitoring, research, and regulatory interaction with local, state and federal agencies. Long-term monitoring programs include monitoring for gaseous pollutants such as ozone, visibility impairment, and atmospheric depositions. More information is available on the IMPROVE (Interagency Monitoring of Protected Visual Environments) web site.