Rangelands are vast, making up one quarter of the United States and forty percent of the Earth’s ice-free land. And while contemporary science has revealed a great deal about the environmental impacts associated with intensive livestock production—from greenhouse gas emissions to land and water degradation—far less is known about the historic role science has played in rangeland management and politics. Steeped in US soil, this first history of rangeland science looks to the origins of rangeland ecology in the late nineteenth-century American West, exploring the larger political and economic forces that—together with scientific study—produced legacies focused on immediate economic success rather than long-term ecological well being. During the late 1880s and early 1890s, a variety of forces—from the Homestead Act of 1862 to the extermination of bison, foreign investment, and lack of government regulation—promoted free-for-all access to and development of the western range, with disastrous environmental consequences. To address the crisis, government agencies turned to scientists, but as Nathan F. Sayre shows, range science grew in a politically fraught landscape. Neither the scientists nor the public agencies could escape the influences of bureaucrats and ranchers who demanded results, and the ideas that became scientific orthodoxy—from fire suppression and predator control to fencing and carrying capacities—contained flaws and blind spots that plague public debates about rangelands to this day. Looking at the global history of rangeland science through the Cold War and beyond, The Politics of Scale identifies the sources of past conflicts and mistakes and helps us to see a more promising path forward, one in which rangeland science is guided less by capital and the state and more by communities working in collaboration with scientists.