The Democratic Republic of Congo is rich in the copper and cobalt for which there is high demand on the world market. In southeastern DRC, large-scale mining (LSM) has a long history, with a recent resurgence following the end of the second civil war in 2003. This revival of LSM investment resulted in the displacement of artisanal and small-scale mining (ASM) by companies. These conflicts, which have received significant attention in academic literature and policymaking, are sometimes conceptualised as pitting LSM companies against artisanal miners in continuous conflict. Yet structural factors are necessary, but not sufficient to explain the variability of conflict at and around LSM sites. Here, I link conflict incidence to the interactions between three key facets of the property rights (PR) regime at and around LSM sites: corporate enforcement, authorised clandestine extraction, and unauthorised clandestine extraction. I contend that the property rights regime is characterised by overlapping claims that reflect the persistence of clandestine mining within LSM concessions, linked to the fact that outside actors push into the not-quite-hermetic space of the mine. Conflict often erupts in a context of strategic (c)overtness when the cost of providing PR and enforcing informal agreements becomes prohibitive for reasons indirectly linked to resource access, including security guards' need to protect their employment, and companies' reputational concerns. The different security forces that govern authorised clandestine mining also use a range of forceful and non-forceful tactics to "close" LSM sites to unpaid access by artisanal miners, but do not always succeed. The interactions of the different facets also have consequences in terms of the distribution of resources among a range of actors and groups including women, different categories of traders, and ethnic communities. This research highlights that corporate PR are in fact negotiated and contested: the public security forces and other government actors define and enforce other PR, not just companies' property rights, in contexts of "illegality". These findings provide a more fine-grained explanation for LSMASM conflict and why artisanal miners frequently operate peacefully at LSM sites, including through local conflict resolution mechanisms that reduce transaction costs hindering agreement. My findings have relevance for many other areas in resource-rich African countries where artisanal miners operate "illegally".