Positive motivation to perform work tasks has been associated with better performance and outcomes in both the organizational and informal education literature. In environmental education (EE), this means that more motivated instructors are likely to provide better programs for their participants. In this exploratory study across 15 states in the USA, grounded in interviews with EE instructors and their supervisors, we examine the most salient factors motivating EE instructors to perform their work and how the practices of their organizations influenced those factors. Organizational practices related to enhancing EE instructors' feelings of autonomy, competence, relatedness, and meaningfulness of their work each contributed to positive motivations. A strong sense of shared values and interests underpinned each of these factors. We discuss recommendations for maintaining and enhancing instructor motivations, including hiring and onboarding strategies, participatory evaluation processes, and professional development opportunities. We also consider subtle differences in motivations at different career stages.