This article describes methods and findings from a study focused on youth living in rural communities in northern New Hampshire who struggle with accessing STEM learning opportunities because of economic underinvestment and geographical isolation. These challenges also negatively impact researchers hoping to learn how rural youth benefit from informal STEM learning experiences because they contribute to low project participation and retention rates. As in other amenity-rich rural areas, the communities in this study are promoting outdoor recreation as a vehicle for economic development. We wanted to understand if outdoor recreation activities tied to economic growth initiatives--activities which youth have ready access to--show promise as a context for informal STEM learning. This article describes the unique research methodologies used in the study, including a mobile application designed around the Universal Design for Learning (UDL) framework. It also highlights the UDL strategies used to employ youth as co-researchers. While multiple factors contributed to the 96% retention rate in this project, the use of the UDL-based mobile app was significant, novel, and holds promise as a future strategy for increasing rural youths' engagement in STEM career and identity development activities.