The dynamics of customary land rights and displacement among east African pastoralists have been the subject of extensive scholarly inquiry. Displacement to make way for other land uses, government-led privatization schemes, endogenous subdivision to defend land against outsiders, and progressive enclosure of private land in the context of the recent 'land rush' are some of the documented trajectories of land tenure change. Less explored is how exogenous authority systems gain traction within common property regimes to re-shape the contours of property. Laikipia, Kenya presents an ideal context for this research given the uniquely ambitious effort to conserve globally significant wildlife on private land. We focus on a group ranch owned collectively by Maa-speaking pastoralists for whom formal title was secured with the support of outside actors vested in conservation, and coupled with efforts to provide financial incentives for conservation. Findings suggest the new governance structure established in the context of land titling has become a pathway through which outside authority gains traction -with consequences for property, sovereignty and the traction of green agendas. Findings deepen understanding of how shifting authority shapes processes of alienation and legitimation, and contribute to ongoing debates about land grabs, tenure formalization and neoliberal approaches to conservation.