Studies of sustainability transitions and transformational change are common in energy and transport sectors. However, there is limited research on how these transformational change processes play out in the natural resources sector, particularly in developing economies. This paper seeks to address this gap, with a case study of the community forestry system in Nepal that has, over the last four decades, reversed Himalayan land degradation and contributed to community livelihoods. The case illustrates comprehensive changes in forest management practices and governance over four decades. Central to this was a ‘thinking movement’ of development agencies, activists and researchers that opened up learning spaces and engage conflicting stakeholders in action-oriented dialogues. While transformation can never be pre-engineered, this study suggests that investment in strengthening locally engaged research capability could be a key way of catalyzing sustainability transitions, both as a continuous process of evolution and transformative shifts during the crisis and political opportunity.