This book tells the history of scientific efforts to understand and manage rangelands—the grasslands, shrublands, savannas, tundra, steppe and deserts that comprise some two-fifths of Earth’s land surface. Beginning around the turn of the twentieth century, the United States Forest Service employed scientists in hopes of rapidly discovering ways to heal damage from overgrazing, maximize the production of forage and livestock, and resolve conflicts about the use of public lands. But the scale and variability of rangelands defied the logics of capital, the state and science alike. Exterminating rodents and predators, suppressing wildfire, and assigning carrying capacities to fenced areas of rangelands were all imposed on western public lands for political and economic reasons, with science serving to justify these measures as apolitical and “natural.” Frederic Clements’ theory of plant succession dominated the discipline for most of the twentieth century, even as early range scientists recognized its flaws and attempted to voice their objections. Perennial conflicts between US federal land management agencies, ranchers, and environmentalists reflect their shared adherence to Clementsian ideas, which were displaced among scientists only after the Western Range model failed, repeatedly and conspicuously, in pastoral development projects in the Third World. Across the West today, community-based conservation initiatives suggest the promise of more collaborative, multi-scaled approaches to managing rangelands.