Project Overview

The Resolution Copper project is a proposed underground copper mine 60 miles east of Phoenix, Arizona, near the town of Superior. The Arizona project is a joint venture between two global mining companies, Rio Tinto (55%) and BHP (45%).

The project has the potential to become one of the largest copper mines in United States.

The copper deposit lies deep underground, between 5,000 and 7,000 feet below the surface. It is considered one of the largest undeveloped copper resources in the world, with studies estimating an average copper grade of about 1.5 percent¹. Over an expected operating life of up to 40 years, the mine could produce as much as 40 billion pounds of copper and supply up to 25 percent of U.S. copper demand.

We have strong community and regional support for the project, which has the potential to become one of the largest copper mines in America, add $1 billion a year to Arizona’s economy, and create thousands of local jobs in a region where mining has played an important role for more than a century.

Resolution Copper continues to work with local communities, Tribal Nations, and regional partners to advance the project responsibly.

You can find updates on where the project stands and what comes next on our current status page.

To learn how the mine would operate, read more about the planned mining method and how copper would be safely recovered deep underground using a well‑established approach called caving.

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 2024 Annual Report released to the ASX on 20 February 2025. Rio Tinto confirms that it is not aware of any new information or data that materially affects the information included in the 2024 Annual Report, that all material assumptions and technical parameters underpinning the estimates in the 2024 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.