The Morenci Mine is the largest copper mine in the US and one of the biggest in the world. As of 2007, operations ran around ...

Rio Tinto Kennecott, the world's largest open-pit mine, is now open for visits for the 2025 season. Operating since 1903, this Utah-based open-pit mine has produced over 19 million tons of copper.

The entrance loomed ahead as we stepped into the vast, echoing marble mine for the first time. Inside, the space opened up into towering chambers and deep pits with water at the bottom. Broken steel ...

The $6 trillion discovery has challenged existing geological theories about how Earth's richest iron ore deposits formed.