The Biden administration has fast-tracked a mine in southern Arizona under a rule that could allow the project to proceed with expedited environmental review.
But local residents say the mine threatens one of the most ecologically diverse places on the planet.
Policy experts say electric vehicles will play a role in offsetting climate change, but they require a number of minerals that must be imported.
During the Obama administration, the government created a program to expedite paperwork on domestic mines that produce those minerals, such as a proposed manganese mine in southern Arizona.
Carolyn Shafer of the Patagonia Area Resource Alliance, which has raised concerns about the project, said the region has vital ecological significance.
"Scientists have identified this region as one of the top five regions in the entire world, most in need of protection for species survival. We have greater biological diversity here than anywhere else in North America," Shafer said.
Conservationists have also raised objections over the Rosemont copper mine in the nearby Santa Rita Mountains.
