Nature-based preschools are defined as educational settings in which children spend three or more hours per school day in natural environments such as woods, meadows, and beaches (Knight, 2013). The purpose of this qualitative, multiple case study was to obtain a deep understanding of the challenges and successes of nature-based preschool (NBP) founders and directors in the United States and to develop recommendations for those interested in establishing and operating NBPs in the United States. A rich description of the phenomenon of founding and directing NBPs was developed by first answering the primary research question: "What can be learned from the challenges and successes experienced by founders and directors of NBPs in the United States?" The study's participants included directors and founders from three NBPs in the United States. Data was collected through semi-structured interviews, public documents, timelines, and through multi-media sources, such as each school's website. Within-case analysis and cross-case analysis was employed to analyze the data, generating the following key themes: experience, relationships, temperament, like-mindedness, mission focus, collaboration, leadership, worldview, and outlook. Recommendations are provided for other NBP founders and directors which may lead to an increase in the number of NBPs in the United States. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]