Partnerships between colleges and universities and K-12 school districts attempt to improve access to higher education by tailoring college outreach and teacher professional development programs to local needs as well as aligning high school curricula with higher education admissions criteria. In this article, we conduct a quasi-experimental evaluation of partnerships between universities and school districts in California. Our fixed-effects models indicate that comprehensive K-16 partnerships substantially increase student graduation and nonselective university enrollment rates in participating school districts, but that these effects take time. We argue that local partnerships are an effective, but resource- and time-intensive, K-16 school reform strategy. (Contains 3 tables and 5 notes.)