Rio Tinto Approves $144 Million Investment for Resolution Copper Project in Arizona

By Robb M. Stewart

Rio Tinto has given the go ahead for a $144 million investment for the next phase of development at a large untapped copper deposit in Arizona that promises to be a major new source of the metal produced domestically for the U.S.

The mining company said its share of the investment in Resolution Copper will total $79 million, with minority partner BHP responsible for the remainder.

The program will fund feasibility studies and final design engineering for the installation of development and production-level material handling equipment in both shafts and new water treatment facilities, Rio Tinto said. It will also support ongoing exploration drilling, the purchase of underground equipment as well as long-lead electrical equipment. The spending comes on top of the about $500 million already earmarked over the next two years.

Rio Tinto said about 50 additional roles will be created across mining and other positions.

"Resolution Copper has the potential to supply up to 25% of America's copper demand for decades, strengthen domestic supply chains and deliver significant economic benefits for Arizona," Rio Tinto Chief Executive Katie Jackson said.

In March, the U.S. Forest Service and Resolution Copper completed a federal land exchange after the U.S. Court of Appeals for the Ninth Circuit denied a request to halt the transfer of 2,400 acres of land adjacent to the historic Magma Copper mine in exchange for more than 5,400 acres of environmentally and culturally sensitive land to the Forest Service and Bureau of Land Management.

Resolution Copper in August handed out about $110 million in contracts to push ahead with exploration and underground development at the mine site.

The companies say Resolution Copper has the potential to become one of the largest copper mines in the U.S., and would create thousands of jobs and add an estimated $1 billion a year to Arizona's economy once in operation.

The copper deposit is located near Superior and lies between 5,000 and 7,000 feet underground. Resolution Copper is operated by a joint venture 55% owned by Rio Tinto and 45% by BHP.

Write to Robb M. Stewart at robb.stewart@wsj.com

(END) Dow Jones Newswires

November 05, 2026 09:56 ET (14:56 GMT)