This qualitative study explores teachers’ critical environmental agency (CEA) through deepening content knowledge, engaging in identity development, developing a critical consciousness of place, and moving toward civic action. We explored the meanings secondary science teachers made of an on-going professional development (PD) situated in the Okefenokee Swamp (unique ecosystem that drains to Gulf of Mexico and Atlantic Ocean) and focused on local watershed citizen science monitoring and the global implications of all water being connected. Data analyses focused on how the nineteen teachers’ experiences and meanings were leveraged to develop CEA and the constraints that restricted their CEA development. Our findings broaden the understanding of how teachers, who teach historically underrepresented youth in low socioeconomic rural areas, come to see themselves as people who care about the environment and become empowered to envision a more sustainable future for their students and communities.