Learning how to teach depends on the dynamic inter-relationships among many parts and people; however, research on learning how to teach has typically focused on confined aspects of teacher education (e.g., a specific methods course) over short periods of time (such as one semester). In response, Wideen, Mayer-Smith, and Moon (1998), in their review of the literature on teacher education, called for an ecological approach to studying the learning-to-teach phenomena. They argued that, "only when all players and landscapes that comprise the learning-to-teach environment are considered in concert will everyone gain a full appreciation for the inseparable web of relationships that constitutes the learning-to-teach ecosystem." To investigate the "learning-to-teach ecosystem", researchers (individually and jointly) should therefore attend to the wide range of those involved--supervisors, university faculty, cooperating teachers, students, and families--as well the landscapes of individual student teachers who bring their own social and cultural positionings, lived biographies, and understandings of teachers' work to the study of teaching. This article reports on a qualitative study of one cohort of elementary student teachers in a public university in California over the course of one year. Applying an ecological approach to studying the process of learning to teach, this research focuses on intersections among identity, role, and agency across the systems of teacher education. (Contains 1 graphic and 3 notes.)