Adult conservation education is growing nationally. We investigated adults' motivations to take part in Michigan's Conservation Stewards education and volunteerism program. We used three theoretical frames (adult education orientations, volunteerism motivations, and leisure benefits sought) to understand learners' involvement. Adults' education motivations were for learning (seeking knowledge) and for participating in the learning activity and its social interactions. Motivations for volunteering were strongest for understanding ecosystems, expressing one's values, and interacting socially. Learners sought leisure benefits of enjoying the outdoors, helping the environment, reflecting, and participating in well-organized projects. Educators should clearly understand learners' motivations in order to improve programs. (Contains 3 tables.)