In a blow to tribes, a U.S. appeals court has denied a last ditch legal effort to block construction of what’s expected to be the largest lithium mine in North America on federal land in Nevada.

In a decision Monday, the Ninth Circuit Court of Appeals ruled that the U.S. government did not violate federal environmental laws when it approved Lithium Nevada’s Thacker Pass mine in the waning days of the Trump administration.

Lithium is a key component of electric vehicle batteries, and despite pressure from west coast Paiute tribes and environmentalists, the Biden administration did not reverse the decision and had continued to advocate for the mine, which would be located on remote federal land near the Nevada-Oregon border.

“We have always been confident that the permitting process for Thacker Pass was conducted thoroughly and appropriately,” says Jonathan Evans, CEO of Lithium Americas in a statement provided to NPR. “Construction activities continue at the project as we look forward to playing an important role in strengthening America’s domestic battery supply chains.”

Tribes and environmental advocates tried for two years to block construction of the mine:

Several area tribes and environmental groups have tried to block or delay the Thacker Pass mine for more than two years. Among their arguments was that federal land managers fast tracked it without proper consultation with Indian Country.

“They rushed this project through during COVID and essentially selected three tribes to talk to instead of the long list of tribes that they had talked to in the past,” Rick Eichstaedt, an attorney for the Burns Paiute Tribe, said in an interview late last month.

The land is considered sacred to some Native people as it’s believed to be the site of at least two ancient massacres. Tribal elders still go there to conduct ceremonies and gather traditional plants.

But in their ruling, the Ninth Circuit judges responded that only after the mine was approved by federal land managers did it become known that some tribes consider the land sacred.

Full construction of the mine is expected to begin in earnest this summer.