Drawing on critical development studies and social movements literatures, this article analyzes how civil-society actors used practical and ideological resources to frame their situations in mobilizing for change. Focusing on a case study of a World Bank-sponsored natural resources management project in Rondônia, Brazil, I examine how the discourse and policies promoting "participatory, sustainable development" have been used to achieve resource conservation, and to promote social justice aims within the current neoliberal policy framework. Based on document analysis and in-depth interviews with civil-society actors, I argue that Rondônia nongovernmental organizations (NGOs) and grass-roots movements successfully mobilized by effectively framing their demands and by forming strong "movement webs" with national and transitional civil-society actors. The case study also explores the divergence in approach and objectives between local NGOs and grass-roots movements, illustrating the practical and political limitations to implementing participatory and sustainable development projects.