In summer 2019, common grazing lands in the Moroccan Middle Atlas Mountains were opened to corporate farming. Families with access rights will no longer be able to herd sheep on the commons, which will instead be divided and leased by the Ministry of the Interior. Yet collective rights holders will retain 'ownership' over these lands, individually receiving rents proportional to the land's value. My dissertation investigates this incomplete dispossession and the resulting transformation of rangeland commons. It does so through analyzing contemporary and historical practices of measurement, valuation, and division that delimit and divide collective lands and shape collective belonging. Further, it looks to the ways in which these calculative logics have been enacted, negotiated, and refused by individuals of different subject positions within the collective whole. Situating the 2019 land leasing within a 90-year history of shifting measurement practices, I ask how the practices through which common rangelands are valuated delimit both the commons and its broader social collective, as well as the kinds of distributive politics they might engender. To this end, this project will leverage historical and ethnographic methods of participant observation, archival research, life history collection, and community mapping to document the ways in which these commons have been divided and defined, including through codified customary law, colonial and state policies, herding practices and regulation, and the distribution of its products. This research is significant because commonlands around the world are currently being transformed through contested calculations of value, divisibility, and ownership. Exploring divergent logics through which rangeland commons are conceptualized, bounded, and put to use, my research seeks to understand the kinds distributive logics that enable collective belonging, and govern differential access.