The Resolution Copper project could supply as much as one-quarter of US copper needs for 40 years. It will be an underground mine near the town of Superior. The company is drilling a shaft to 7,500 foot depth, but is waiting for Congress to act on a land exchange bill the company says is necessary for them to proceed. [Right, diagram of proposed underground block caving method. Credit, Resolution Copper mine plan of operations]
The other two top ranked projects are the La Granja copper project in Peru, and Australia's South of Embley bauxite project.