Lithium Americas started construction on the Thacker Pass lithium mine last week after the 9th U.S. Circuit Court of Appeals denied a request by environmental groups to temporarily halt work on the site, pending an appeal.

In a statement, Lithium Americas CEO Jon Evans said “starting construction is a momentous milestone for Thacker Pass.” Initial construction includes site preparation work and building a pipeline, with major earthworks for the mine expected to start later this year. Analysts watching the race to develop a mineral supply chain for electric vehicles said it was a milestone, with one telling E&E News that the mine “would make Nevada sort of the Silicon Valley of lithium production.”

Since a federal permit for the mine was approved in 2020, the lithium project has faced criticism from environmental groups, tribal governments and local residents over its impact on imperiled wildlife, Indigenous cultural sites and the character of rural communities surrounding the project. 

In February, U.S. District Court Judge Miranda Du largely dismissed the challengers’ arguments that the federal government erred in approving the mine permit and upheld the 2020 approval, a rare move after deficiencies were found in the government’s interpretation of the Mining Law of 1872. 

The plaintiffs appealed the decision to the 9th Circuit and filed an emergency motion with the federal court, asking it to halt construction until legal arguments on the appeal could be heard by the judges. But the court declined, paving the way for the mine construction to move forward. 

“It’s a truly unfortunate outcome for the land, wildlife, and cultural resources of this area,” Talasi Brooks, a staff attorney with Western Watersheds Project, said in a statement on Friday. “This massive open pit mine has been fast-tracked from start to finish in defiance of environmental laws, all in the name of ‘green energy,’ but its environmental impacts will be permanent and severe.”

The 9th Circuit will hear arguments on the pending appeal later this year.