Exotic species are recognized as a major threat to biodiversity. Understanding what factors facilitate invasion is of great conservation value, as this will allow for more specific and targeted efforts to prevent future invasions. Of particular interest are unique habitats such as the iconic United States National Parks. Though National Parks have some legal protections against some forms of habitat degradation, they are still vulnerable to the introduction of exotic species. They can threaten native species populations and alter ecosystem function. The purpose of this study is to characterize species invasion in National Parks and identify what environmental conditions may contribute to invasion. We used plot-level and park-level data from 165 National Parks and National Historic Monuments throughout the United States and correlated exotic species richness and percent cover with various predictor variables using statistical regression analysis. We hypothesized that factors that increase human impact and transit, such as distance to roads and visitation, would contribute to an increase in invasion. We also hypothesized that exotic species abundance would be negatively correlated with native species richness, indicating that diverse native communities can resist invasion. We also considered the alternative hypothesis that exotic species abundance would be positively correlated with native species, indicating that habitats favorable for native species are also favorable for exotic species. I will discuss the results during my Steinmetz presentation. These results will be used to better assist in conservation efforts of National Parks in the future.