The field of environmental education has sometimes been compared to a thriving, robust tree with the tree's many branches representing the diversity and variety in the field. Given the differing definitions, the many programs, the plethora of materials, and the fractal like growth of the field, perhaps the comparison with a tree is apt. But, what lies underground? What are the roots of the field? As with a tree, the roots of environmental education are widespread and diverse. They provide support for the present field while supplying the nourishment for future growth. Does environmental education owe its origins to the influence of philosophers such as Jean-Jacques Rousseau (1712-1778) who felt that education should maintain a focus on the environment, or to educators such as Louis Agassiz (1807-1873) who encouraged students to "study nature, not books"? As indicated in the timeline in this document, it is easy to see the deep roots that support the environmental education field. This multifaceted history is one reason for the diversity, resilience, and inclusive nature of environmental education today.