Land use change in tropical places with variable topography followed an elevation-sensitive pattern during the last 3 decades of the 20th century. Deforestation, driven by farmers, was concentrated in accessible, lowland settings, while sustainability initiatives, promoted by natural scientists, occurred in remote, upland settings. This lowland deforestation–upland sustainability pattern persists, but the drivers of sustainability initiatives have recently changed with the emergence of organizations of rain-forest–dwelling indigenous peoples that promote upland sustainability. This article describes and, by means of a case study, explains this shift in sustainability dynamics. Indigenous groups have gained more control over the lands they inhabit, and their populations have increased. With these changes, indigenous peoples' organizations have assumed pivotal roles in upland sustainability initiatives. The history of indigenous control over sustainability efforts where the Andes meet the Amazon in southeastern Ecuador, an area inhabited by the Shuar, illustrates this pattern of change.