In 2016, the Colombian Constitutional Court recognized the Atrato River as a subject of rights based on the theory of biocultural rights. This dissertation analyzes a new legal concept that aims to defend the rights to a good life for humans and other-than-human co-inhabitants who share river ecosystems, focusing on the case of the Atrato River in Colombia. The 3Hs framework of biocultural ethics is adopted to interconnect complex and interrelated historical, biophysical, cultural, and political dimensions. With this analysis, broader biocultural approaches are suggested. They could be valuable for understanding and implementing biocultural rights in other world regions. Moreover, it could transform the current situation that destroys biocultural diversity toward public policies that favor more just and sustainable forms of co-inhabiting biocultural diversity. A primary limitation of the implementation of biocultural rights is the context of a "failed state," in which the Colombian State is subject to severe problems of corruption, illegal mining, conflicts between legal and illegal armed groups, and drug trafficking. There is a need for a dialogue solution to the conflict. This requires that illegal armed groups are valued as co-inhabitants. Achieving social-environmental justice is essential for biocultural ethics. In this case, it is the condition of possibility for the ruling of biocultural rights of the Atrato River to be entirely carried out.