The emergence of hundreds of rural, place-based, grass-roots ecosystem management (GREM) efforts across the United States constitutes a new environmental movement that challenges the fundamental premises of existing natural resources and public lands institutions. This article establishes GREM as qualitatively distinct from prior American environmental movements and as a fundamentally different approach to the environmental problematique, which relies on decentralization, collaboration, citizen participation, and a holistic worldview that seeks to simultaneously promote environment, economy, and community. GREM is compared with the three major American environmental movements preservation, conservation, and contemporary along several dimensions: ideology, movement character, preferred institutions, and approach of each to science, technology, and the question of limits to growth. While not all aspects of GREM are new, it is a grand synthesis that borrows readily from past movements, adds new ideas and approaches to environmental management, and transforms the whole into a distinctive movement worthy of study.