This paper documents the first year of a qualitative case study investigating the experiences of reciprocal learning teams of teachers within a small, rural secondary school. The purpose of this study was to examine how teachers experienced collaborative professional development (PD) and how their experiences contributed to developing the culture and structure of their school. Collected data were analyzed using an iterative process of coding, categorizing, and abstracting data. Three themes emerged: (a) self- and co-regulated learning in teams invigorated collegial relationships and contributed to a sense of agency toward change at the school level; (b) differentiating support for collaborative inquiry among teachers and within teams is critical; and (c) creating structures to support collaborative inquiry among teachers engages teachers in their ongoing professional learning. This case study of a rural secondary school demonstrates how deep and substantial school change can happen when teachers co-construct and co-regulate their PD.