Native American group Apache Stronghold gather outside 9th Circuit Appeal Court in California
Apache Stronghold, a Native American group hoping to protect their sacred land from a Cooper mine in Arizona, gather outside the 9th Circuit Appeal Court in Pasadena, California,U.S., March 21, 2023. Reuters

The U.S. Forest Service plans to re-publish an environmental report before July that will set in motion a land swap between the U.S. government and Rio Tinto, allowing the mining giant to develop the controversial Resolution Copper project in Arizona.

The move would be the latest blow to Native Americans who have long opposed the mine project, which would destroy a site of religious importance but supply more than a quarter of U.S. copper demand for the green energy transition.

The complex case centers around a land swap approved by Congress in 2014 that required an environmental report to be published, something the Trump administration did shortly before leaving office. President Joe Biden then unpublished that report in March 2021 to give his administration time to review the Apache's concerns, though he was not able to permanently block the mine.

Meanwhile, Apache Stronghold, a nonprofit group comprised of members of the San Carlos Apache tribe and others, sued to prevent the transfer of the federally owned Oak Flat Campground, which sits atop a reserve of more than 40 billion pounds of copper, a crucial component of electric vehicles. Several courts have ruled against the group.

Joan Pepin, an attorney for the Forest Service, told an en banc hearing of the 9th U.S. Circuit Court of Appeals on Tuesday that "the prediction for that (new environmental report) is to be ready this spring."

The Forest Service is not waiting for the court's ruling to publish the new report, Pepin said, adding that the agency does not believe an 1852 treaty between the U.S. government and Apaches gives Native Americans the right to the land containing the copper.

"This particular treaty is just a peace treaty. It doesn't settle any rights to land and it doesn't create any land rights," Pepin told the court.

The Apache Stronghold held a ceremony outside the Pasadena, California, courthouse on Tuesday to protest Rio's plans for the copper mine.

Reuters images showed some protesters drumming while others displayed placards with the words "Save Oak Flat" and "What will we do when the last mine is mined?" in the rain.

The 11 judges at the hearing peppered all sides about the legal concept of substantial burden and whether the government can do what it want with federal land, even if it prevents some citizens from fully exercising their religious beliefs. A full ruling is expected in the near future.

A Rio Tinto spokesperson said the company is closely following the case and respects the legal process, but believes "that settled precedent supports" the rejection of Apache Stronghold's claims by a lower court. Rio has said it will smelt copper from the project inside the United States.

Representatives for Apache Stronghold and the San Carlos Apache tribe were not immediately available to comment, nor were representatives for BHP, which is helping Rio develop the mine.

"It is my hope that ... the government will correct a troubling double standard in the law that has disenfranchised Native American practitioners and continued a history of callous disregard of their sacred sites by the government," said Stephanie Barclay of Becket Law, a conservative legal group dedicated to religious rights that opposes the land swap.