All 11 members of the 9th U.S. Circuit Court of Appeals will hear a case regarding the Resolution Copper project in Arizona. At issue is whether the federal government improperly gave Rio Tinto Plc thousands of acres in Arizona for its Resolution Copper mining project.

Reuters reported that three members of the court had previously ruled in favor of Rio Tinto and the land swap in June. No date has been set for the new hearing.

The dispute centers on the federally owned Oak Flat Campground, which some Apache consider home to deities and which sits atop a reserve of more than 40 billion pounds of copper, a crucial component of electric vehicles. If a mine is built, it would create a crater 3 km (2 miles) wide and 304 m (1,000 ft) deep. Opponents of the mine argue the mine could potentially damage the site.

In 2014, Congress and then-President Barack Obama approved a complex deal to give Rio Tinto the land. A bill under consideration now would undo that deal, though that bill is expected to fail.

The project is a top priority for the company’s leadership.

“There is significant local support for the Resolution Copper project, and we will continue our efforts to understand, address and mitigate the concerns raised by others,” Rio spokesman Simon Letendre said.

Apache Stronghold, a nonprofit group comprised of members of Arizona’s San Carlos Apache tribe and others, cheered the ruling.