The opening of a new high school is an exciting time for students and teachers alike. Teachers learn to collaborate, to experiment, and to shape the systems and structures they desire as a professional community of educators. As the role of the teacher continues to evolve, how we conceptualize the professional educator, and how we act on those beliefs is constantly being challenged and re-imagined as we struggle to fill teacher vacancies and search for ways to better prepare our future educators. As a teacher leader in a new school, my problem of practice centers on a concept I call the teacher professional culture, and how we as teachers in our new school interacted and engaged with one another, administration, and the community to develop our professional identity, our roles, and our collaborative structures. As a teacher leader in this new school, Beachside High School, I set out on a practitioner inquiry in which I examined two wonderings aimed at exploring how we as teachers define our teacher professional culture and what elements of that professional culture we deem important in our new school, and in what ways those elements support professionalism and trusting relationships among faculty at Beachside High School. In collecting data for my inquiry, I invited two focus groups of teacher leaders (one of Department Chairs and one of Professional Learning Community leaders) to reflect on our experiences in year one at Beachside High School. In addition, one interview with our Instructional Literacy Coach, an end of year PLC reflection video, and a written self-reflection facilitated my learning through practitioner inquiry. Through inquiry, I came to learn how we as teachers in a new school defined the professional educator and the value we placed on professionalism in this context. Additionally, I came to understand how we constructed and maintained our roles and collaboration, and how our behaviors contributed to the establishment of trusting relationships among colleagues. My learnings highlight the importance of our professional behaviors, our teacher leadership roles, our formal collaboration, and our purposeful interactions in the creation of our teacher professional culture. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]