National parks are seeing more visitors than ever, raising concerns over the environmental conditions in the park. Past research on national park designation has focused on economic impacts; however, there is less literature on the environmental impacts. This thesis explores the environmental impact of national park designation, looking specifically at the Indiana Dunes National Park. Air pollution measures collected by the EPA in Porter County were analyzed to explore a relationship between air quality and an increase in visitors after national park designation. This paper also used a survey to gain an understanding of how stakeholders view the impact of tourists on the area. Questions were on erosion, flora, fauna, water pollution and air pollution. Analysis found that national park designation did increase visitor rates but was not related to any of the air pollution measures. Respondents expressed concerns over the environment due to tourists’ actions, mainly for flora and fauna. The findings of this thesis urge the conservation plans of the national parks to be altered to better address parks’ carrying capacity for visitors.