Post-secondary students benefit from mentorships, which provide both emotional and academic support tailored to the unique challenges they face. STEM students, and, in particular, those with historically marginalized identities, have unique strengths and face distinct barriers that can be ameliorated by careful, knowledgeable, and well-situated mentoring relationships. With that in mind, we conducted a narrative case study with 10 rural-Appalachian STEM majors enrolled in an NSF-funded mentoring program, intending to collect stories of their impactful experiences with their mentors. We utilized the narrative reconstruction process, and, in so doing, identified five major themes related to the importance of mentor assignment and the impact of mentors’ characteristics and skills related to empathy, consistency, active listening, and teaching. We situate our findings within the existing literature and provide implications for scholars and practitioners who work with mentoring programs dedicated to working with Appalachian communities.