The book addresses the concept of informal learning in social movements. It reviews the academic literature on informal learning by adults and young adults. It presents experiences of environmental social movements and the learning processes that take place in these processes. The author presents research conducted while pursuing his doctoral dissertation in adult education at Northern Illinois University. They illustrate a production of knowledge ranging from the skills and abilities needed to organize social struggles to experience and knowledge about the natural environment. Research suggests that the use of participatory action research (PAR) as a tool for research and transformation in the conceptual framework of popular education encouraged participants to become aware that their experiences and practices produce knowledge.