Oregon State University-Cascades, in collaboration with the University of Oregon and Portland State University, will address the challenge of building, expanding and sustaining high-quality computer science (CS) programs in K-12 schools throughout Oregon. The project team will investigate how teacher preparation, retention, and school-level administrative support create lasting CS educational opportunities for all students and investigate how this comprehensive approach creates lasting pathways for expanding and sustaining CS education across Oregon. The project outcomes will benefit society through having a more computationally literate pipeline of students for college, careers, creative endeavors, and civic participation. The CS for Oregon CSforAll High School Strand Research-Practice Partnership brings together expertise in Computer Science Research, Education Research, and High School teaching practice and works closely with key personnel from the Oregon Department of Education (ODE) such as the Oregon team participating in the NSF-sponsored Expanding Computing Education Pathways (ECEP) Alliance. The project staff will prepare existing teachers with any credential to teach Exploring Computer Science, an evidence-based course shown to engage all students. Alongside teacher preparation, the project researchers will support and study how experienced CS teachers deepen their practice through action research while building agency as educational leaders to expand and sustai