In 2005, Project PASS—Proficiency And Success in Science—was funded as a Mathematics and Science Partnership by the Nevada Department of Education. This three-year collaborative project was initiated with the goals of improved quality of instruction and subsequent student achievement on the Nevada high school science proficiency exam. It also sought to support the implementation of a recently revised, integrated, freshman science course emphasizing scientific inquiry. For many of the teacher participants, Project PASS helped to bring about important changes in their teaching practices. Using vignettes written by three participating teacher teams, this chapter describes the use of authentic classroom inquiry, its impact on student learning, and the potential of professional development for scaffolding the PASS experience.