Resource and visitor experience degradation in Haleakalā National Park resulting from recreational use of the Pools of 'Ohe'o has led park officials to discourage visitor use of the pools. This study uses the Theory of Planned Behavior (TPB) to examine relationships among visitors' attitudes, subjective norms, and perceived behavioral control with regard to exploring the pools, their intentions to explore, and their actual behaviors while visiting the pools. Further, this study examines the influence of persuasive messages on visitors' behavior at the pools. Persuasive message treatments emphasize either the dangers of exploring the Pools of 'Ohe'o or resource protection and visitor experience impacts of recreational use at the pools. Through regression analysis of attitudes, norms, and perceived behavioral control with intention to explore, TPB is generally found to be an effective model for understanding visitor behavior at 'Ohe'o's Pools, particularly when visitors are exposed to persuasive messages. Results of analysis of variance indicate that the TPB model components of attitudes and subjective norms with regard to traveling companions and National Park Service officials are influenced by exposure to the persuasive treatment messages. Additionally, both intention to explore the pools and observed exploration behavior are significantly lower among those visitors receiving any persuasive treatment message. Thus, results of this research generally support the individual relationships assumed within TPB. With identification of the most influential components of visitor behavior, as understood through the TPB model developed in this study, managers of Haleakalā National Park will be able to develop and apply persuasive interpretive messages that maximize safe and sensitive visitor recreational behavior at the Pools of 'Ohe'o. / Master of Science