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History

A Legacy of Copper in Arizona

Arizona has a diverse cultural history, especially in the Copper Triangle. For more than a century, mining and ranching have played an important role in shaping local communities

Copper is a cornerstone of Arizona’s history and economy. Since 1910, the state has been the nation’s leading producer of copper. Today, approximately 68 percent of the copper produced in the United States comes from Arizona. The copper star at the center of the Arizona flag reflects the industry’s lasting importance to the state.

A Century of Mining in the Copper Triangle

Mining has long influenced the landscape and communities of the Copper Triangle. While mining brings change, it also carries responsibility. Resolution Copper is committed to protecting the surrounding land during operations and through closure and reclamation.

Respect for cultural and historical significance is built into how Resolution Copper plans the project. Learn more about how we protect cultural heritage.

The Pioneer Mining District traces its roots to the mid‑1800s. In 1875, the Silver King Mine began producing silver, marking the start of large‑scale mining in the area.

In 1912, the Magma Copper Company’s underground mine began operations in Superior. For more than 80 years, the mine played a central role in building the town and shaping the region’s mining identity, operating until the mid‑1990s.

After the mine closed, interest in developing a deep copper deposit near Superior, while reusing the already disturbed Magma Mine site, kept the property active. In 2004, Resolution Copper Mining assumed control of the site.

Arizona has been mining country for generations. By placing Arizona resources and workers at the center of this project, Resolution Copper builds on that history while supporting the state’s role in domestic mineral production.

Resources

Our Work

New Water Recycling System Reduces Annual Use by One Million Gallons

A new Potable Water Recycling System is now operating on site, reducing water use by an estimated one million gallons per year. The system captures clean analyzer water and returns it to the plant for reuse, replacing water that was previously discharged onto the ground.

Reflecting on His Past, Bryan Mines a New Future

Bryan’s family is no stranger to mining. Born and raised in Globe, Bryan grew up watching his father and uncles work at the Magma Copper Mine. The industry was volatile at the time, and Bryan’s father was laid off three different times. Wanting a more stable path for his son, Bryan’s father encouraged him to do anything else for a living. Bryan followed that advice and decided to enroll at the University of Arizona, where he earned his Bachelor of Science degree in economic development.

Apache Owned Business to Manage Oak Flat Campground

Resolution Copper reaffirms that public access to the Oak Flat Campground, as well as to recreational roads and climbing areas on private land in the Oak Flat area, will remain open for the foreseeable future following completion of a federal land exchange this month.

United States Forest Service and Resolution Copper Complete Land Exchange

The U.S. Forest Service and Resolution Copper, a joint venture owned by Rio Tinto and BHP that represents one of the world's most significant untapped copper deposits, have completed a Federal land exchange required to unlock the full potential of the project.

Eight Years of Emory Oak Restoration and Cultural Stewardship

Across Arizona’s National Forests, Emory oak trees and the restoration of their groves support far more than wildlife and shade. For Western Apache communities, these trees provide acorns that are central to food traditions, ceremonies, and cultural practices that stretch back generations.

Resolution Copper in the Community: 2025 Recap

If there’s one thing 2025 proved, it’s this: engaging with the community isn’t a side project for us. Across the Copper Triangle and surrounding communities, Resolution Copper showed up in hundreds of ways, big and small. Some days it looked like volunteers packing food bags. Other days it looked like robotics kits in classrooms, filling sandbags, or youth baseball teams taking the field.

$4.5M Invested in Local Communities in 2025

Together alongside local partners, we invested over 4.5 million dollars to support students, families, communities, small businesses, and the places we all care about in the Copper Triangle region. The year was full of real moments that changed lives in quiet, meaningful ways. A robotics team getting their first competition kit. Families picking up holiday meals with dignity and relief. Teachers gain new tools for hands-on learning

Inside Our Underground Concrete Work on 68L

At Resolution Copper, we recently completed a major upgrade on 68L, one of the key levels deep in our underground system. The work was a collaboration between our team, Redpath, and Oddonetto, and it is a good window into what it takes to build strong mining infrastructure before full operations begin.

Resolution Copper Donates $285,000 to United Food Bank

Resolution Copper has donated $285,000 to Mesa-based United Food Bank to support the nonprofit’s mission and work in the Copper Corridor, tribal communities, and in the East Valley. The multi-year agreement through December 2028 comes at a critical time when there is record demand for food among all populations, including seniors and working families.