This paper traces the evolution of a theory of learning in nature in order to explain how people learn in natural settings. The intellectual roots of the theory in informal learning, cognition, affective development, experiential and meaningful learning are described and the synthesis into a comprehensive theory of learning in nature are explained. The evolution of the theory is traced through several iterations describing the addition of organizing concepts as well as efforts seeking simplicity in its conceptualization. An in-depth case study of meaningful learning about bogs illustrates how the theory can be applied to explain environmental learning experiences. The implications for this theory in terms of environmental education are discussed. (Contains 6 figures.)