The Social Licence to Operate (SLO) is increasingly used in extractive industries both as a response to calls for greater community engagement and as a corporate sustainability strategy. Given its current popularity as a policy instrument, critiques on the SLO deserve attention. Critiques mainly focus on ambiguities that surround the processes of granting and maintaining the SLO. This article explores the negative social and environmental impacts that these ambiguities may obscure from sight. It applies a critical research approach to a case study of the diversion of the river Undai as part of the Oyu Tolgoi mining project in Mongolia and the associated construction of a SLO. The results show that neutralising discourses obscured harmful impact on nature and society. Moreover, the SLO was intimately entwined with changes in the landscape and livelihood strategies that had a harmful effect on both the livelihoods and the social identity of herders. The analysis thus validates existing critiques on the SLO and calls for more authentic engagement with local communities that specifically includes the recognition of harm.