In a longitudinal investigation of young children's developing relationship with and understanding of the natural world, eleven preschoolers and their teacher were filmed for 50 hours during weekly explorations at a local state park. Findings indicated that while outdoors children showed self-awareness with regard to environmental features, generated complex scientific theories around discoveries, and engaged in environmental stewardship. The teacher provided sensitive guidance for children's individual and collaborative explorations and for their appreciation of nature. The findings provide support for the premise that children's understanding of the natural world develops through direct, engaging experiences, supported by adult guidance and encouragement.