Natural Resource Damages (NRD) are defined as injury to, destruction of, or loss of natural resources. The measure of damages under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Oil Pollution Act (OPA) is the cost of restoring injured natural resources to their normal condition, compensation for the interim loss of injured resources pending recovery, and the reasonable costs of a damage assessment.

In Montana, the state Natural Resource Damages Program (NRDP), a division of the state Department of Justice, administers settlement funds from a lawsuit (parts of which are still ongoing) against the Potentially Responsible Parties in the Butte, Anaconda, and Upper Clark Fork Basin Areas for historic environmental damages and restoration costs beyond those stipulated by EPA and the Superfund program.