Under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), natural resources are "land, fish, wildlife, biota, air, water, ground water, drinking water supplies, and other such resources. . .”. The Oil Pollution Act (OPA) contains a similar definition of natural resources.
Colorado has trusteeship over any natural resources and their supporting ecosystems that the State owns, manages or controls, or has a responsibility to protect. The State’s trusteeship over natural resources is not necessarily exclusive, because the federal government and tribes have rights, responsibilities, and interests in natural resources located within Colorado. In many cases, Colorado’s trusteeship overlaps with that of federal trustees. To date, the State’s natural resource damage claims have not involved natural resources under tribal trusteeship.
The scope of the State’s trusteeship in a given case depends on the affected natural resources and the State’s rights, responsibilities, authorities and interests in those resources. In general Colorado has trusteeship over state lands; state rare, threatened and endangered species; fish and wildlife resources; and surface and groundwater.