Abstract: The Mongolian Rangelands and Resilience (MOR2) project was developed collaboratively by physical, ecological and social scientists, pastoralists, conservation practitioners and government decision-makers. We aimed to 1) increase understanding of the effects of climate change on Mongolian pastoral systems, 2) investigate the role of formal community-based rangeland management in building resilience to climate and other changes, 3) strengthen natural resource science and policy linkages in Mongolia, and 4) train US and Mongolian students and researchers in interdisciplinary approaches to complex environmental problems. The project generated important scientific findings, but the most transformative impacts may have arisen from the transdisciplinary research process, which included commitments to reflexivity and reciprocity at multiple levels from the core research team (12 individuals), to Mongolian partner researchers and technicians (over 40 individuals), to the practitioners, policy-makers and herders involved in project design and engaged in the interpretation and application of results (> 200 people). This talk considers the lessons learned and trade-offs involved in conducting large-scale transdisciplinary research grounded in a participatory and collaborative research ethic, the role of gender in transdisciplinary research, and how our experience leading/participating in this project transformed our understanding of the purpose and process of transdisciplinary science.