Teachers’ professional growth is far better documented within elementary professional development schools than it is within multi-site school partnerships at the secondary school level. This article fills an empirical gap by focusing on the professional development of 35 secondary school teachers and two professors within a school/university teacher education partnership focused on one content area. The University of Georgia Network for English Teachers and Students (UGA-NETS) is attached to a Research I institution and committed to on-going, discipline-based, collaborative inquiry and the education of 25 teacher candidates each year. Analysis of surveys, focus group and individual interviews, field notes, and documents across 5 years reveals that participants perceive 4 sites for their own professional development: individual school and university classrooms, school and university departments, the teacher network, and teacher education locally and beyond. The author also presents challenges to professional development within multi-site and secondary school partnerships including disturbing the status quo and the question of agendas, levels of buy-in, and diversity and equity.