The current literature relates to how teachers develop knowledge and practice of science inquiry, but little has been reported on how teachers develop interdisciplinary science inquiry (ISI) knowledge and practice. This study examines the effect of university research experiences, ongoing professional development, and in-school support on teachers' development of ISI pedagogical knowledge and practices. It centers on documenting diverse teachers' journeys of experiencing ISI as well as developing knowledge of ISI. It was found that there was variation in ISI understanding and practice among the teachers as a result of the combination of teachers' experiences, beliefs, and participation. Thus, in order to help teachers develop ISI knowledge and pedagogy, barriers to ISI knowledge development and implementation must also be addressed. Professional developers must articulate clear program goals to all stakeholders including an explicit definition of ISI and the ability to recognize ISI attributes during research experiences as well as during classroom implementation. Teachers must also be held accountable for participation and reflection in all aspects of professional development. Program developers must also take into consideration teachers' needs, attitudes, and beliefs toward their students when expecting changes in teachers' cognition and behavior to teach inquiry-rich challenging science.