The Holden Mine Cleanup Project is a federally mandated mine cleanup and remediation effort in Washington’s Okanogan-Wenatchee National Forest. The goal of the cleanup project is to address environmental problems left by the operation of the Holden Mine in the 1930s-1950s. The cleanup was necessary to reduce water and soil contamination, prevent future contamination and help restore the natural ecosystem.

Rio Tinto never owned or operated the Holden Mine but inherited the responsibility through a series of business acquisitions.