Project Overview

The Resolution Copper deposit ranges from 5,000 to 7,000 ft (1,500 to 2,130 m) below the surface.

The deposit’s average grade is estimated at 1.5% copper¹. The proposed underground mine is expected to become the largest copper mine in North America, capable of producing up to 25 percent of U.S. copper demand each year.

Our aim is that the mine will produce as much as 40 billion pounds of copper over 40 years.

History

The area around Superior, Arizona, has a long mining history dating back to the 1870s. The Magma Mine, located in the Town of Superior, started production in 1910 and operated until 1996.

The potential to develop a rich new copper deposit near Superior and reuse the already disturbed historic Magma Mine kept the site active and alive after closure. In 2004, Resolution Copper Mining assumed control of the Magma Mine site.

Resolution Copper started the US permitting process in 2013, and since the US Forest Service (USFS) has conducted a comprehensive independent review under the National Environmental Policy Act (NEPA). Following a rigorous and lengthy permitting process, a decade of construction will occur before mining can begin.

To date, project partners (55% by Rio Tinto and 45% by BHP) have spent over $2 billion to develop and permit the Resolution Copper project.

Permitting

There is no doubt that mining changes the landscape. We’re committed to protecting the land and surrounding area while we operate and after mining is complete.

To date, we have initiated a variety of land management and restoration programs to protect and balance the delicate interaction between critical environmental factors. Examples include cleanup of the historic Magma Mine site, Arizona hedgehog cactus preservation, and monarch habitat conservation.

We will continue to work with the community and our partners to progressively rehabilitate land during the life of our operations.

Before we can construct or operate the proposed mine, we need approval from federal, state, and local agencies. This process includes getting our plans for the mine approved by the federal government in accordance with the NEPA requirements.

The Permitting Process

In 2013, Resolution Copper submitted a Mine Plan of Operations to the U.S. Forest Service (USFS), the federal agency in charge of the approval process. The document outlined our proposed plans to design, construct, operate, and close the mine. We also stated how we would reclaim and restore the area once mining is complete. The plan included baseline data about the water, air, and biology in and around the project and our plans to protect these valuable resources.

Next, the USFS formally announced its plan to develop a Draft Environment Impact Statement (EIS) for the project, which provided the public opportunity to comment on the proposed plan. What followed was years of community engagement in the review process.

In August 2019, the agency issued a Draft EIS. The Draft EIS included information about project impacts on the environment, how to mitigate or offset those impacts, and alternatives to the mine plan. After the public reviewed and commented on the draft EIS, the USFS and other agencies began conducting additional analysis of our plan. As a result, the agency may require us to change or refine our proposal.

In January 2021, the USFS published a Final EIS that addresses the public’s comments and any changes made, six months behind the target date in its original project schedule set in 2015. The USDA directed the USFS to rescind the FEIS in March 2021 to allow the agency to undertake a further review. A federal land exchange will take place not later than 60 days after the publication of the Final EIS.

Once the Draft ROD is released, the public has 45 days to object to the decision, and the USFS must respond and address any concerns within 90 days. Once this period is complete, and we receive a Final ROD and the USFS can issue a final approved plan of operations.

Only after we receive final approval, and dozens of additional permits, can the Resolution Copper project move forward and begin producing copper.

Learn More

• Permitting process on the US Forest Service website
• Land Exchange parcels fact sheet (16mb PDF)

¹ This copper grade for the Resolution Mineral Resource was reported in accordance with the JORC Code and the ASX Listing Rules in Rio Tinto’s 2023 Annual Report released to the ASX on 23 February 2024. Rio Tinto confirms that it is not aware of any new information or data that materially affects the information included in the 2023 Annual Report, that all material assumptions and technical parameters underpinning the estimates in the 2023 Annual Report continue to apply and have not materially changed, and that the form and context in which the Competent Persons’ findings are presented have not been materially modified.