Resolution Copper (RC), a joint venture owned by
Rio Tinto and
BHP, has proposed conducting
underground mining of a copper-molybdenum deposit located below the ground surface. The company estimates that the mine would take approximately 10 years to construct and would have an operational life of approximately 40 years which would be followed by 5 to 10 years of reclamation activities. In 2014, just hours before the vote on the
NDAA, Senator
John McCain added a land exchange deal to the bill, which President
Barack Obama signed. The Act cleared the way for the land swap in which Resolution Copper would receive of National Forest land in exchange for deeding to the federal government of private land. An independent appraisal of the exchanged lands found that the value of lands Resolution Copper has offered for Oak Flat is about $7 million, while the Oak Flat parcel is valued at over $112 billion. McCain and Flake's
rider was Section 3003 of the NDAA, titled "Southeast Arizona Land Exchange and Conservation Act", which would allow RC to develop and operate an
underground copper mine deep in the publicly owned
Tonto National Forest near
Superior, Arizona. The mine would excavate an area set aside in 1955 by President
Dwight D. Eisenhower during an expansion of the Tonto National Forest. The land contains more than of the Oak Flat Campground, an area dotted with petroglyphs and historic and prehistoric sites. The former San Carlos Apache tribal chairman Wendsler Nosie Sr. said of the Act's
rider: "This is Congressional politics at its worse, a hidden agenda that destroys human rights and religious rights." The San Carlos Apache Tribe, under the leadership of Chairman Terry Rambler, has led a strong opposition to the RC land exchange. Both the
National Audubon Society in Tucson and the Grand Canyon Chapter of the
Sierra Club in Arizona along with the
National Congress of American Indians have joined in the fight to Resolution's land grab.
James Anaya, former
United Nations special rapporteur on the rights of indigenous peoples, said that without community and tribal support, Rio Tinto should abandon its Resolution Copper mining project.
United States Secretary of the Interior Sally Jewell said she was "profoundly disappointed with the Resolution Copper provision, which has no regard for lands considered sacred by nearby Indian tribes". By January 2015, over 104,000 had signed a petition to President Obama titled "We the People|Stop Apache Land Grab". Jodi Gillette, Special Assistant to the President for Native American Affairs, quickly gave an official
White House response, vowing that the Obama administration would work with Resolution Copper's parent company Rio Tinto to determine how to work with the tribes to preserve their sacred areas. Scientists warned that the mining project would create a large
sinkhole about wide and deep, and would deplete and contaminate Arizona's already limited groundwater supply. In March 2016, the National Park Service added Oak Flat to the National Register of Historic Places as a historic district and
Traditional Cultural Property. Arizona Republican Congressman
Paul Gosar, who has characterized the dispute with the San Carlos Apache as "bogus", condemned the Historic Places designation by the Obama administration and the Forest Service as "sabotaging an important mining effort." The project has not met all federal surface water and groundwater requirements, yet the Forest Service under the Trump administration rushed the environmental analysis despite the impacts described according to a draft
environmental impact statement released in late 2019 by the U.S. Forest Service. This report did not include adequate studies of impacts to the area nor did it consider any alternatives to the plans for the mine. In protest, hundreds of Apache tribe members and supporters walked for four days in February 2020 from San Carlos Apache Indian Reservation to Oak Flat, a distance of . The march was sixth in an annual series. President Biden issued the Memorandum on Tribal Consultation and Strengthening Nation-to-Nation Relationships in January 2021. The final environmental impact statement was withdrawn by the United States Forest Service in March. Citing the memorandum, the Forest Service said they need more time to fully understand concerns raised by the tribes. On March 18 that year, Representative
Raúl Grijalva reintroduced the Save Oak Flat Act for the fourth time, which would repeal the mandate to transfer the land transfer of Oak Flat to Resolution Copper. On February 19, 2021, the Apache Stronghold, an Apache-led coalition seeking to preserve the sacred land, sued to prevent the mine's construction, arguing that the land transfer violated the
Religious Freedom Restoration Act and the 1852 Treaty of Santa Fe. In March 2024, the
9th U.S. Circuit Court of Appeals ruled that the project did not impose a "substantial burden" on the religious rights of the Apaches people. In August 2025, the 9th U.S. Circuit Court of Appeals issued a temporary restraining order on the mine. In March 2026, the
Ninth Circuit rejected claims brought by a coalition of preservation groups and Apache tribal members challenging the land transfer. The Supreme Court denied an appeal. Oak Flat was transferred from the Forest Service to Resolution Copper on March 13 2026. ==References==