Resolution Copper, America’s largest untapped copper deposit, is inching closer to reality, but the path forward is fraught with challenges that could reshape the mining sector’s approach to domestic resource development. Nestled beneath the Arizona desert, this massive underground deposit holds an estimated 28 million metric tons of copper, valued at approximately $270 billion at current market prices. Once operational, it could supply roughly 25% of America’s domestic copper needs, a critical consideration as the U.S. seeks to reduce dependence on foreign sources amid surging demand for this essential metal in renewable energy, electric vehicles, and advanced manufacturing.
The strategic importance of Resolution Copper cannot be overstated. As Gracelin Baskaran, director of the critical minerals security program at the Center for Strategic and International Studies, notes, “We’re at a point where mining companies are very hesitant to mine in the US because of the long permitting and litigation times. Seeing a project like Resolution enter production would be an important signal to the mining sector.” This hesitancy is reflected in troubling statistics—according to S&P Global, the average timeline between discovery and commercial production for U.S. mines stretches to 29 years, the second-longest globally after Zambia. Resolution’s eventual success could help reverse this trend, potentially catalyzing other domestic copper investment trends critical to America’s industrial future.
However, the journey to production is far from straightforward. The Resolution copper deposit lies at extraordinary depths, requiring miners to descend more than a mile underground. This makes Resolution one of the deepest mining operations in North America, pushing the boundaries of what’s technically possible in underground resource extraction. At these depths, temperatures reach a blistering 175°F (79°C), creating conditions that would be lethal without extensive intervention. Massive cooling units run constantly, generating a pervasive mist throughout the tunnels. These challenging conditions have necessitated innovative approaches to worker safety, equipment design, and operational planning that go far beyond conventional mining practices.
The project is a joint venture between Rio Tinto Group and BHP Group, two of the world’s largest mining conglomerates. These global mining powerhouses have demonstrated extraordinary patience and commitment, having invested over $2 billion in the project across two decades without extracting a single ounce of copper for commercial purposes. This long-term vision reflects both the exceptional value of the deposit and the companies’ understanding of the extended timelines typical for major copper system analysis in the United States.
Despite substantial financial commitment and extensive underground development work, actual production remains years away. This extended timeline illustrates the complexity of developing world-class mining projects in the modern regulatory environment, where environmental, cultural, and technical considerations must be carefully balanced with economic objectives. Resolution Copper faces a labyrinthine regulatory process spanning multiple government agencies at both state and federal levels. The project still awaits state air and groundwater permits, approval of its mine reclamation plan, and various federal authorizations. The Trump administration has estimated the project will receive all necessary federal permits by February 2026—representing more than a decade in the permitting process alone.
Perhaps the most emotionally charged challenge comes from the San Carlos Apache Tribe, whose reservation lies approximately 70 miles from the project site. The tribe considers Oak Flat, which falls within the project’s footprint, a sacred site of profound cultural and spiritual significance. For centuries, the Apache have used this area for religious ceremonies, coming-of-age rites, prayer circles, and healing rituals. The land also contains burial sites, petroglyphs, and ancient cultural artifacts that represent irreplaceable connections to tribal heritage and identity.
Environmental advocacy groups have also raised significant concerns about the project’s water usage during Arizona’s severe drought conditions and the permanent alteration of recreational areas valued by local communities. As Roger Featherstone, director emeritus of the Arizona Mining Reform Coalition, succinctly states: “Bottom line—the project is not worth the risk any way you look at it.” The U.S. Forest Service has estimated that 41 years of mining would create a surface crater approximately 1.8 miles in diameter and up to 1,115 feet deep, permanently transforming the landscape.
Resolution Copper plans to employ block-caving, an advanced underground mining technique particularly suited to large, deep ore bodies. This method involves creating an extensive network of tunnels beneath the ore deposit, then strategically detonating explosives to fracture the ore. The fractured material then collapses downward through gravity, allowing for efficient collection. This approach requires massive upfront investment in infrastructure and years of preparatory development work before production can begin. However, once operational, block-caving can be more economically efficient and environmentally preferable to open-pit mining for accessing deep deposits like Resolution.
The technological sophistication of Resolution Copper stands in stark contrast to historical mining methods used in the region. The historic Magma mine, which connects to Resolution, operated for 86 years until 1