The major federal public land management agencies (the Forest Service, Bureau of Land Management, Park Service, Fish & Wildlife Service, and Department of Defense) have increasingly adopted a language that did not exist twenty- five years ago-the language of ecosystem services. Ecosystem services are the range of benefits that ecological re- sources provide to humans, from water purification and pollination to carbon sequestration and wildlife habitat. The scientific discipline advancing the ecosystem services frame- work arose in the mid-1990s and quickly became a central strategy for fusing ecology and economics research. Despite its ascendance in research communities, the recognition and conservation of ecosystem services in law and policy has been a more gradual, incremental process. While largely unrecognized, the federal public land management agencies have been embedding consideration of ecosystem services in their policy decision making. Looking back, it is remarkable how far this quiet revolution has come. This Article traces that policy evolution and assesses why it happened, how it happened, and what it means for the future of public land management. The Article concludes by arguing that federal land management agencies' emphasis on the flow of ecosystem services from public lands to off-site human communities rebuts arguments that public lands would be better managed by privatization or by increased resource extraction.