The purpose of this qualitative, heuristic inquiry was two-fold: First, the study explored the lived experiences of four teacher leaders working in one comprehensive high school in a district where the researcher is superintendent. The second purpose was to learn from the experiences of the teacher leaders to inform district level actions that could develop structures and resources to support of the work of these and other current and emerging teacher leaders. The study addressed these questions: (a) What are the teacher leaders' personal and professional histories, qualities, and dispositions? (b) What is the nature and purpose of the work of these teacher leaders? (c) What are the contextual elements of the school district that either support or create challenges for the work of these teacher leaders? (d) What is the impact of the work of these teacher leaders? (e) What lessons can be drawn from the work of the teacher leaders to inform my actions as superintendent and improve school district structures and processes in order to support and encourage the work of these and other teacher leaders? Data were collected through individual and focus group in-depth interviews. In addition, since this was a heuristic study, the researcher also kept journal notes regarding learning from the perspective of the superintendent, actions that were taken as a result of this learning, and observations of various meetings and workshops related to these action. Based on this data, portraits of the four teacher leaders were developed to illustrate the teacher leaders' history and dispositions, the work they chose, and the context in which the work took place. Analysis of the data resulted in 19 themes organized into 4 major categories: Teacher leader dispositions, purposes of teacher leadership, means of teacher leadership, and context of teacher leadership. Based on this analysis, a conceptual framework for teacher leadership was developed that emphasizes the interactive, interdependent nature of the components of teacher leadership identified in this study. The heuristic approach resulted in a set of learning and actions taken with the school district. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]