/ Project Overview

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.

Resources

Our Work

Meet the People Behind the Core

There are jobs where you work with spreadsheets. Jobs where you work with heavy equipment. And then there are jobs where working with rocks is literally part of the assignment. Welcome to the Core Processing Facility.

Resolution in the Community: September 2026

Resolution Copper participated in 77 community engagements during September, bringing our 2026 total engagements to 556. Behind those numbers are teachers finding new ways to engage students, volunteers helping neighbors, community partners thinking about the future of the Copper Corridor and opportunities to learn directly from Tribal communities.

Teamwork Powers 46 Level Upgrade

Deep underground at Resolution Copper, crews recently completed a major upgrade to the 46 Level pump station, modernizing a critical system that helps manage water in the mine's underground workings.

A Decade of Showing Up

Since 2016, Resolution Copper has invested more than $20 million through more than 900 partnerships supporting rural Arizona communities.Those partnerships span education, health and wellbeing, culture and heritage, environmental stewardship, business development, recreation and community economic development.

More Than a Game: How Baseball Became a Classroom

Since 2012, Resolution Copper and the Arizona Diamondbacks have worked together to create opportunities for Arizona youth, educators and communities. What started with Science of Baseball has grown into teacher workshops, hands-on STEM experiences, youth baseball clinics, Tribal youth programming and community recreation.

Stewardship Starts Here | Stephen’s Story

Stephen learned early in life that taking care of the environment matters. His father spent his career working in renewable energy and taught him the importance of respecting the earth and preserving it for future generations. Those lessons stuck.

From Trails to Roadsides: Stewardship in Action

There are plenty of things you might expect to see during a day at Resolution Copper. Engineers solving problems. Teams working underground. People in meetings. Hard hats, high-vis and plenty of equipment.

Home Again: Mike’s Story

A Superior native reflects on leaving home, coming back and building a career close to the place that shaped him. Growing up in Superior, Arizona, Mike spent his afternoons coming home from school, jumping on his dirt bike and heading straight into the desert.

The Descent: What It’s Like Traveling Nearly 7,000 Ft. Underground

From the surface, 7,000 ft. is hard to picture. It is just a number until you walk toward the shaft, pass beneath the headframe and reach the collar, where the scale starts to come into focus. The opening drops below, surrounded by steel, hoisting equipment and the systems that move people safely between the surface and the underground workings.