This article tests the project-based research model by analyzing the processes and outcomes of a partnership between a grassroots environmental organization promoting community-based sustainability practices and a series of university-based capstone courses. We begin by contrasting scientist-driven and community-based approaches to sustainability. We then describe a series of three knowledge mobilization projects codesigned by The Natural Step Monona (TNSM) and university-based capstone courses led by a graduate student and professor. The first project performed a community diagnosis, from which we codesigned a prescription that the second capstone course helped TNSM implement. The third course worked with TNSM to evaluate the process. That evaluation, along with follow-up interviews, showed that the process had substantial and concrete positive community impacts that furthered TNSM’s mission, but it also led to partner fatigue as the organization was pushed past its realistic capacity.