The money keeps moving at Superior. Resolution Copper announced on November 5 that it will invest $144 million to advance the next phase of development at its copper project near Superior, Arizona — a deposit between 5,000 and 7,000 feet underground that the company describes as one of the world's largest untapped copper deposits. The spend is the first major tranche since the historic land exchange was completed in March 2026, the step that unlocked this phase of the project.
- The commitment: $144 million by Resolution Copper Mining LLC — Rio Tinto's share is $79 million, with joint-venture partner BHP holding the remaining 45% interest. The project is operated by Resolution Copper Mining, owned 55% by a Rio Tinto subsidiary and 45% by BHP Copper Inc.
- On top of what came before: the $144 million is additional to approximately $500 million of preliminary spending announced on March 16, 2026, when the land exchange closed.
- What it buys: feasibility studies and final design engineering for the installation of development and production-level material handling equipment in both shafts and for new water treatment facilities.
- Also in the program: ongoing exploration drilling, purchase of underground development and production equipment, and procurement of long-lead electrical items — transformers, circuit breakers and switchgear.
- The hires: an additional 50 roles will be hired, including mining, geotechnical and geology technicians, geologists, engineers and project services staff.
- The stated prize: the company says Resolution has the potential to supply up to 25% of America's copper demand for decades, become one of the largest copper mines in the United States, and contribute approximately $1 billion annually to Arizona's economy — all company-stated potential, not production fact (see the honesty box).
What this phase actually is
This is engineering-and-equipment money, not a construction decision. The work it funds — feasibility studies, final design for shaft material handling, water treatment design, drilling, and early procurement of electrical gear that takes a long time to manufacture — is the work a project does to position itself, in President Vicky Peacey's words, "strongly for its next investment decision."
Peacey framed the step plainly: "This investment builds on the momentum created by the historic land exchange and marks another important step towards unlocking Resolution Copper's potential. Resolution is one of the world's largest untapped copper deposits and can become a major new source of copper for the United States, supporting American industry, jobs and economic growth for decades to come." She added that the program "will accelerate underground development and our path towards first copper production while maintaining safe underground operations and construction."
The honesty box
An investment approval is not a mine. The $144 million, the $79 million Rio Tinto share, the 55/45 ownership and the March 2026 land exchange are stated facts from the release. Everything beyond that is forward-looking: no final investment decision, construction decision or production start date is announced here, and "first copper production" remains a path the company says it is on, not a scheduled event. The headline figures — up to 25% of U.S. copper demand and roughly $1 billion a year to Arizona's economy — are the company's own statements of potential for a fully built mine, not forecasts with a date attached, and the deposit's depth (5,000–7,000 feet) is a reminder of the engineering scale involved. The 50 roles are positions the company says will be hired under this program, not positions already filled.
What to watch
The feasibility and final-design work this money funds, and whether it produces the project's next formal investment decision; hiring against the 50-role program in Superior; and delivery of the long-lead electrical equipment, which will show how much of the plan is moving from paper into steel.