WASHINGTON – The Supreme Court on Tuesday rejected an appeal from Apaches who are fighting to halt a massive copper mining project on federal land in Arizona that they hold sacred.

The justices left in place lower court decisions allowing the transfer of the Tonto National Forest land, known as Oak Flat, to Resolution Copper, which plans to mine what it says is the second-largest known copper deposit in the world.

The Trump administration has said it will push to complete the transfer.

Justice Neil Gorsuch wrote in dissent that it was a “grievous mistake” not to take up the appeal.

“Recognizing Oak Flat’s significance, the government has long protected both the land and the Apaches’ access to it,” Gorsuch wrote, joined by Justice Clarence Thomas. “No more. Now, the government and a mining conglomerate want to turn Oak Flat into a massive hole in the ground.”

A group known as Apache Stronghold, representing the interests of certain members of the San Carlos Apache Tribe, has argued that the land transfer will result in the destruction of the site in violation of its members’ religious rights.

Apache tribes in Arizona consider Oak Flat, which is dotted with ancient oak groves and traditional plants, essential to their spiritual well-being.

An estimated 40 billion pounds of copper could be mined over the lifetime of the mine, according to the U.S. Forest Service.

The project has significant support in nearby Superior and other traditional mining towns in the area. The company estimates the mine will generate $1 billion a year for Arizona’s economy and create thousands of local jobs.

Resolution Copper is a subsidiary of international mining giants Rio Tinto and BHP.

Justice Samuel Alito did not take part in the case, presumably because he owns between $15,000 and $50,000 worth of BHP stock, according to his most recent financial disclosure.

Congress approved a land swap in 2014 that would give Resolution Copper 3.75 square miles (9.71 square kilometers) of forest land in return for eight parcels it owns in Arizona.

In the waning days of the first Trump administration, the U.S. Agriculture Department issued the required environmental review that would allow the land swap to proceed.

Apache Stronghold sued in federal court to block it. With the change in administrations to President Joe Biden, the Agriculture Department, which includes the Forest Service, pulled back the review to further consult with Native American tribes.

But the suit proceeded and a year ago, the federal appeals court in San Francisco split 6-5 to allow the land transfer to go forward, rejecting Apache Stronghold’s arguments about religious freedom and its invocation of a 1852 treaty between the U.S. government and the Apaches.

The five dissenting judges described the outcome as a tragic error that would result in “the utter destruction” of the sacred site.

The Forest Service already has provided the 60 days notice that it intends to re-issue the environmental review, as required by a court order.