In the University Classroom Observation Program (UCOP), middle and high school teachers spend time on campus observing science, technology, engineering, and mathematics (STEM) classes and engaging in discussions with colleagues and college instructors. The program provides a unique and reciprocal professional learning opportunity. Middle and high school teachers learn to use an observation protocol to collect data in STEM classrooms. These data serve as feedback for individual college instructors; help provide an aggregate snapshot of teaching throughout the university; and contribute to faculty professional learning opportunities, new teaching and learning initiatives, and the larger discipline-based education research (DBER) literature. UCOP offers middle and high school teachers discussion and networking opportunities to reflect on their own teaching and on ways to better prepare their students for college. Here we describe the program, articulate the benefits for stakeholders, reflect on lessons learned, and discuss important considerations for the development of similar programs.