What are students' mental models of the environment? In what ways, if any, do students' mental models vary by grade level or community setting? These two questions guided the research reported in this article. The Environments Task was administered to students from 25 different teacher-classrooms. The student responses were first inductively analyzed in order to identify students' mental models of the environment. The second phase of analysis involved the statistical testing of the identified mental models. From this analysis four mental models emerged: Model 1, the environment as a place where animals/plants live - a natural place; Model 2, the environment as a place that supports life; Model 3, the environment as a place impacted or modified by human activity; and Model 4, the environment as a place where animals, plants, and humans live. The dominant mental model was Mental Model 1. Yet, a greater frequency of urban students than suburban and rural students held Mental Model 3. The implications to environmental science education are explored.