Environmental protection is widely considered a core function of the state. Yet more than 210 million people currently live under the control of armed non-state actors (ANSAs), many of whom exercise state-like authority over vast, environmentally important territories. Despite growing legal and political science scholarship on ANSAs, their role in environmental protection remains largely unexplored. International law, shaped by conflict-centric frameworks, often fails to account for ANSAs’ non-military dimensions – especially those related to environmental service provision. Similarly, theories of rebel governance have yet to meaningfully incorporate environmental service provision as a governance facet. The article addresses this gap by examining the Revolutionary Armed Forces of Colombia – People’s Army (FARC-EP) in Colombia, drawing on documentary analysis and interviews with former combatants. It shifts the limited ecological perspective on war, arguing that the FARC-EP’s environmental practices amounted to a form of rebel environmental governance – structured, intentional and legally plural. Through this case study, the article challenges dominant narratives that view ANSAs solely as environmental spoilers or incidental protectors and instead advocates for a more comprehensive understanding of their impact as environmental service providers and lawmakers. In doing so, the paper reframes ANSAs as socio-legal actors whose environmental practices merit scholarly attention – particularly in ongoing debates around accountability and transitional justice in conflict-affected regions.