Resolution Copper’s proposal to build a huge domestic copper source in Arizona’s protected forests is close to realisation.

Rio Tinto’s Phoenix-based subsidiary received legislation approval from the Senate Energy and Natural Resources Committee to develop a mine on Tonto National Forest in Arizona in exchange for the company’s 5,500 acreage of high-priority conservation lands.

The initial bill would have authorised the land swap to move ahead with giving the secretary veto power.

The revised bill will now be sent to the US Senate, and in case it is signed into law, Resolution can proceed with development of the mine.