ABSTRACT
Atmospheric deposition of air pollutants represents an important potential threat to aquatic and terrestrial resources in Rocky Mountain (ROMO) and Glacier (GLAC) national parks, especially at higher elevations. Terrestrial resources in ROMO and GLAC are varied and include alpine and subalpine plant communities, boreal forests, wetlands, and meadows. Aquatic resources in these two parks include a wealth of lakes and streams of exceptional quality. The natural lakes and stream valleys were formed by glaciation. The majority of the surface waters in these parks are found in alpine and subalpine settings, most of which are accessible only on foot or horseback. Many high-elevation surface waters are fed by small glaciers. Because of the remoteness of so many surface waters in ROMO and GLAC, some of the human impacts on water quality are minimized. Human population centers around Rocky Mountain Network parks are sparse, except along the eastern edge of the Colorado Front Range (Figure 18.1). ROMO is located within about 25 mi (40 km) of the Colorado Front Range urban corridor, which has the highest human population density in the Rocky Mountain region (Dennehy et al. 1993). This corridor experienced an increase in human population of about 53% from 1980 to 2000 (Porter and Johnson 2007). ROMO has been especially well studied with respect to impacts from air pollutants. With the exception of anthropogenic atmospheric contributions of pollutants and climate change, direct human impacts on most lakes, streams, forests, and alpine areas in these parks are limited. Especially at remote locations, potential impacts from causes other than air pollution and climate change are restricted mainly to a few dams and irrigation channels, as well as the impacts of hiking, camping, and horseback-riding activities.
