Recent publications argue that to prepare teachers of all grade levels to be confident and competent in incorporating environmental education into their classrooms, pre-service teacher training is effective (e.g., J. T. McDonald & Dominguez, 2010). But the systems in which teachers learn and work are complex, making professional learning about, and implementation of, environmental education both disparate and limited (Franzen, 2017). This study sought to understand the nature of participants' experiences within and between teacher preparation and in-service learning systems as they relate to environmental education. Cultural historical activity theory (CHAT) provided a framework to allow for deeper understanding of the systems of university-based teacher preparation and K-12 schools, as well as influences of the state department of education. By focusing on how learning is influenced by cultural, historical, and social factors, CHAT allowed for a systems approach to understand study participants' experiences. I used a phenomenological research approach (Vagle, 2014) involving teachers, school administrators, and faculty members from the teachers' pre-service preparation programs, generating data through interviews and artifact analysis. Participants reported several challenges related to the inclusion of environmental education: motivation versus implementation, transitioning from university learning to in-service teaching, and the availability of professional learning about environmental education. Additionally, participants identified sources of innovation such as place-based education and champions within all three systems. A discussion of these results is offered, leading to a series of suggestions for informal educators outside of the three systems to assist in advancing the inclusion of environmental education within K-12 learning. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]