This dissertation uses participant ethnography data to examine organizational change and sensemaking processes at a locally elite independent high school in the Midwest. Drawing from sensemaking theory (Coburn 2001; Weick 1995), this dissertation analyzes how social forces shape the ways that actors notice, ignore, and make shared meanings in the organizational environment. The locally elite independent school is defined as an ideal type, and its legitimating idea and organizational form create the conditions for the appropriation of resources by organizational actors and also for overlapping identities that blur the boundaries between work and personal roles, especially in the boarding school setting. Comparing the predictions of market and institutional theories for reform initiatives, this dissertation finds that a school leader crafts a legitimacy project using both selective isomorphism and market elements, but also that actors in the institutional environment add legitimacy to new reforms while demand-side forces from organizational stakeholders constrain innovation. Finally, among the collective sensemaking processes of teachers under a new leadership regime, this dissertation finds evidence for dynamic coupling processes as meanings are contested, identifying the characteristics that lead some teachers to a collapse in meaning and an experience of "turmoil" resulting from inadequate frames for enacting a sensible work environment.