Outdoor education and interpretation programs have the capacity to change how people think about the earth as their home. Many of these interpretive programs are staffed entirely by volunteers. The initial and retention motivations of these volunteer interpreters have a direct effect on the quantity and quality of programs available to the general public. We examined why volunteer interpretive guides at a Northern California Reserve chose to volunteer and how their relationship with the natural environment and their experiences with environmental education influenced their interest in the program and their connection to the Reserve. To answer these questions, we interviewed 15 volunteer interpreters, observed them in training, and leading walks for the public over the course of one year. We found that volunteer interpretive guides shared common experiences that connected them with natural environments, but that their paths to becoming a volunteer guide and their interests in the program were varied. Guides shared an interest in teaching and learning and similar passions for the outdoor environment and all guides referred to the impact of a special natural place from their youth. However, it was the personal passions and subject specific interests of the interpreters that drove their interest in volunteering and their interactions with the participants on their outings.