The park exists within the overall environment.
Every park is affected by environmental factors originating outside its boundaries. In the case of the Natchez Trace Parkway, this is even more true than usual. The park, while 444 miles in length, averages only 800 feet in width. Therefore, when areas beyond the park boundary are affected by a pervasive environmental factor, the park is in no way immune to the impacts. This is true whether we are talking about regional air quality issues, watershed contamination, rampant urban development, or the introduction of non-native species
. If anything, sometimes these effects are noticed even more in a park setting, because we have come to expect national parks to be refuges from modern pollution in all its forms. By observing how factors present in the overall environment affect the quality of park resources, maybe we will be reminded of the need to protect our environment wherever we happen to be.