This Integrating Research and Practice project aims to make lifelong environmental learning and stewardship a reality by using a Design-Based Research (DBR) approach to collaboratively adapt the existing California Naturalist (CalNat) certification program for the context of prison gardens. The study of science learning outcomes will investigate the impacts of two main innovative program features: 1) co-developed hands-on rigorous naturalist training with incarcerated participants, and 2) participation in and contributions to authentic environmental science research. This research-practice partnership offers a unique opportunity to examine combined effects of doing real science, pursuing a CalNat certification, and engaging in outdoor garden spaces on participants' science identities, and what resources, facilitation, and other supports enhance this work. The project is designed around the following research questions: How do 1) hands-on field ecology training and 2) participation in environmental science research influence participants' a) self-efficacy toward science and environmental issues, and b) science identity? The project addresses these research questions through the case of a California Naturalist certification program implemented in a prison garden setting. The project will study the two main learning outcome areas through observations and interviews to discern what aspects of the program most strongly influence participants' learning outcomes, including but