Shenandoah National Park (SHEN) has among the most comprehensive air quality monitoring and research program of all national parks and wilderness areas that are afforded special protection under the Clean Air Act. The park’s monitoring and research program focuses on visibility, acidic deposition, gaseous pollutants, and the acid-base status of streams. E&S Environmental Chemistry prepared a comprehensive, state-of-the-science assessment of Shenandoah National Park’s air quality and related values for use as a tool in the air policy, planning, permit review, scientific, and outreach arenas. This assessment by E&S and collaborating university and federal agency scientists evaluated the current and possible future status of air quality and air pollution effects in SHEN. It focused on the park’s key known air quality related values (AQRVs), including visibility, streamwater chemistry, fish, soils, and vegetation, and the human-caused air pollutants that most affect them. Project completion was May 2003. Products included an agency report and a peer reviewed scientific journal article.