The mining giant Rio Tinto has removed a major legal obstacle to work at the Resolution Copper deposit in Arizona, obtaining control of critical acreage through a federal land swap and pressing ahead with exploration plans. After an appeals court refused to block the transfer and the U.S. Supreme Court declined to intervene, the company announced it would begin an extensive drilling program to examine portions of the orebody that were previously off-limits.
That move follows a multi-decade development effort and more than US$2 billion in prior investment, and it sets the stage for new technical studies that will inform future construction and production decisions.
Under the land swap with the U.S. Forest Service, Resolution Copper received roughly 2,400 acres thought to contain in excess of 40 billion pounds of copper, while transferring about 5,400 acres back to federal stewardship. The exchange is part of the Southeast Arizona Land Exchange and Conservation Act and carries broad strategic implications: the project is projected to deliver more than a quarter of U.S. copper demand over its operating life, reinforcing federal priorities for domestic critical mineral supply chains. Still, the path ahead blends technical ambition with lingering controversies over cultural, environmental and permitting issues.
Table of Contents:
Land swap, court rulings and ownership
The recent legal developments culminate a long series of disputes that reached federal appellate courts. A Ninth Circuit panel concluded that the Forest Service complied with requirements under NEPA (National Environmental Policy Act) and rejected requests to halt the transfer, echoing earlier rulings against challenges that began with Apache Stronghold in 2026 and were revisited in 2026 and an en banc decision in 2026. The appeals court acknowledged the severe cultural impact the transfer would have on the San Carlos Apache, but found plaintiffs were unlikely to prevail on the legal claims. With the U.S. Supreme Court declining to take up the matter, the transfer cleared a key judicial hurdle and enabled Resolution Copper to plan near-term activity.
Exploration program and economic considerations
Drilling and technical work
Rio Tinto has committed to a US$500 million drilling campaign to evaluate the newly accessible sections of the deposit, a necessary step to refine resource models and establish realistic timelines for development. The program will target previously inaccessible zones and produce the geotechnical, hydrological and grade data used to build feasibility studies. These studies will underpin decisions around mine design, capital expenditure and production phasing, guiding when and how the partners—Rio Tinto with 55 percent and BHP with 45 percent—could move into construction and eventual output.
Processing, markets and execution risks
Even with new access, substantial execution risks remain. Detailed metallurgical and permitting work is unfinished, and analysts note that current U.S. smelting capacity and domestic pricing arrangements may not absorb all production into local value chains. That raises the prospect that some of the mine’s output could be shipped as concentrate rather than being processed on U.S. soil. Additional uncertainties include approval timelines, cost inflation, and the need to translate exploration results into bankable plans, all of which will shape whether the partners can meet their stated ambition to bring production online in the early- to mid-2030s.
Community, conservation and continuing controversy
Local management and protected lands
Resolution Copper and government agencies say public access and recreational uses around Oak Flat will continue. In a March 23, 2026 announcement, the company confirmed the Oak Flat campground and nearby roads remain open and that an Apache-owned firm, 4Winds Contracting, will manage campground operations. Michael Woodbury, a San Carlos Apache entrepreneur, will lead maintenance and visitor services, a move framed as part of a broader effort to maintain access and build community relationships. The land exchange also conveyed nearly 5,500 acres of high-value conservation terrain to federal ownership, protecting riparian corridors and culturally significant landscapes in perpetuity.
Cultural impact and legal backdrop
Despite administrative and conservation concessions, the project continues to face intense opposition from the San Carlos Apache and conservation groups who maintain that Oak Flat is a sacred site. Plaintiffs have pursued religious freedom and environmental claims across multiple court rounds, arguing the transfer and subsequent mining would irreparably harm cultural practices. Courts have repeatedly determined that procedural and substantive legal thresholds were not met to block the exchange, while acknowledging the grave harms described by tribal representatives. With litigation largely resolved for now, advocacy groups have signaled they will continue to pursue legal and public avenues to contest the project.
