Agrarian transformations in Andean Peru, subject to larger sociopolitical and economic processes, entailed major material, environmental, and biological changes. The long history of sheep introduction in Andean environments, its specific impact on the central highlands, and the making of an Andean breed of sheep—the oveja Junín—illustrate how such transformations shaped rural Peru as a societal space. Following larger environmental patters in Latin America, sheep became the dominant animal of the upper Andean regions, populating depleted landscapes and refashioning otherwise hostile environments as areas of agrarian productivity. Many of the transformations that occurred during colonial times, particularly the consolidation of the hacienda system and the rise of sheepherding as a form of peonage, served manifold purposes in the transition to the national period. While the 19th-century liberal obliteration of corporate identities and property obscured the legacy of indigenous communities, sheep continued to thrive and set the conditions for the incorporation of the Peruvian countryside into the global world economy. In the 20th century, with the parallel arrival of state and capital governance, transforming sheep and sheepherding from vernacular expressions of livelihood into advanced forms of modern agrarian industrialism merged together scientific and veterinarian knowledge with local understandings, producing the oveja Junín as the ultimate result. As sheepherding modernized based on efficient husbandry, sheep modernity efficiently nurtured rural developmentalism, bringing together communal and capitalist interests in unprecedented ways. The state-sponsored project of granjas comunales devoted to capital-intensive grazing economies reveals how husbandry and modern grazing activities both reinforced and transformed societal organization within indigenous communities, sanctioning existing differences while providing a vocabulary of capital for recasting their internal social relations of production. When the state envisioned the centralization of otherwise profitable communal grazing economies, through the allegedly empowering language of agrarian reform, the cooperativization of land, labor, and animals led to communal, family, and individual disenfranchisement. Indigenous community members, turned into campesinos, sought new battlegrounds for resisting state intromission. Eventually, the very biology of the oveja Junín as an exclusive domain of state and capital became the target of campesino sabotage. As the agrarian reform collapsed and revolution engulfed the countryside, rural livelihoods—sheep included—faced their ultimate demise, often with severe degrees of violence. In this entire trajectory, sheep—and the oveja Junín—ruled the upper regions of the Andes like no political power ever did.