Teacher learning communities are hailed by many as vehicles for reforming and elevating the professional status of teaching. While much research explores teacher community as a venue for measurable gains, our research examines the orientation of practitioner inquiry toward critical debate about effective instruction. Specifically, our study focuses on a group of middle and high school teachers who worked with a nonprofit organization to engage students in urban environmental field investigations. Teachers met regularly as a community with the common goal of teaching urban ecology in an outdoor setting. We collected interview data from members of the teacher community, and we observed teacher interaction during a meeting of the practitioner inquiry group. Interview results indicated that while the nonprofit aimed to support collaborative dialogue and self-critique, participants saw the community mainly as a venue for pursuing short-term goals, such as receiving new resources or socializing with colleagues. Observation data, however, suggested that the community was taking early steps toward building an environment oriented toward critical discussion. Juxtaposing results from our interviews and observations, we discuss the challenges communities face when they seek to develop shared beliefs and deal openly with conflict. Ultimately, we suggest that organizers of collaborative learning environments should work to actively develop structures for building the organizational trust necessary to support civil critique.