Our wilderness and alpine ecosystem areas are a unique resource. While these areas are in remote locations they are not isolated from long-range atmospheric transport. The increase in regional air pollution sources may expose them to anthropogenic pollutants. The Clean Air Act of 1990, as amended, charges the Federal Land Manager (FLM) with the affirmative responsibility to protect air quality related values (AQRVs) in Class I wilderness areas from adverse human-caused air pollution impacts. Class I areas are wildernesses larger than 5000 acres (including later expansions) that existed as of August 1977. This protection is available through implementation of the Act's Prevention of Significant Deterioration (PSD) provisions. But there are constraints the PSD process imposes on the gathering of relevant data for the permit evaluation. Conventional approaches are inadequate to address impacts to vegetation within these constraints.