The U.S. Supreme Court on Tuesday declined to hear an appeal from members of the San Carlos Apache Tribe seeking to stop a copper mining project on federally owned land in Arizona known as Oak Flat.
The decision leaves in place a lower court ruling that permits the federal government to transfer the Oak Flat land in the Tonto National Forest to Resolution Copper, a joint venture of international mining firms Rio Tinto and BHP. The company plans to develop what it claims is the second-largest known copper deposit in the world.
Oak Flat is considered sacred by Apache communities, who say the mine would destroy a site central to their spiritual and cultural practices.
The case was brought by Apache Stronghold, a nonprofit group representing Apache tribal members, who argued the land transfer violates their religious rights and treaty protections.
Despite widespread opposition from tribal advocates, the mine also has support in mining towns such as Superior, where locals see economic opportunity. The project is expected to generate $1 billion annually for Arizona’s economy and create thousands of jobs, according to company estimates.
The land swap was originally approved by Congress in 2014, authorizing Resolution Copper to obtain 3.75 square milesof forest land in exchange for eight parcels it owns elsewhere in Arizona.
The Forest Service initially issued an environmental review in early 2021 under the Trump administration, paving the way for the transfer. However, under the Biden administration, the review was pulled for further tribal consultation.
In 2023, a federal appeals court ruled 6–5 to allow the land exchange to move forward, rejecting religious freedom claims. The five dissenting judges warned the decision would lead to “the utter destruction” of a sacred site.
While the Forest Service has indicated plans to reissue the environmental review, the Supreme Court’s refusal to intervene allows the land transfer to proceed.
Justice Samuel Alito did not participate in the case, citing ownership of stock in BHP.
Supporters of Oak Flat’s preservation say they will now shift their focus to Congress and continued legal efforts in lower courts.
