A federal appeals court has upheld a judge’s ruling that could block approval of an open-pit copper mine in southern Arizona’s Santa Rita Mountains.

Attorneys for a coalition of conservationists said the Forest Service never should have approved the project.

The agency argued that it had little choice; mining is allowed under a law that has been in place since 1872.

But the coalition argued that damage from Rosemont would extend far beyond the actual mine, because plans included massive waste dumps and mining infrastructure. 

A judge agreed, and in a 2-1 vote, the 9th U.S. Circuit Court of Appeals upheld the ruling.

Arizona tribes celebrated the decision, while 8th District Congresswoman Debbie Lesko introduced legislation to revive Resolution Copper Mine near Superior.

EDITOR'S NOTE: This story has been updated to clarify that Debbie Lesko introduced legislation to revive Resolution Copper Mine.