▶ Watch Video: The environmental debate behind reopening the Stibnite Mine

For 150 years, miners have come to the Stibnite Mine located in central Idaho to dig their fortune. The latest arrival: Perpetua Resources, a Canadian mining company looking to reopen the mine which hasn’t been used in more than two decades.

The mine was abandoned in the 1990s. Changes to the river that flows through the mine site caused the fish to spawn upstream—leaving them without clear passage to the Pacific Ocean. This caused the fish decay to contaminate the river, but Laurel Sayer, CEO of Perpetua, told CBS News’ Jeff Glor the company could clean up the mess left behind by, for one, reconnecting the river.

In the 1940s, antimony, a chemical element that is a byproduct of gold, was mined here and used in the production of ammunition that helped the U.S. win World War II. Today, the vast majority of antimony is produced in China and Russia, which some say is a national security risk. Sayer said reopening the Stibnite Mine would help solve this problem.

“If we sit and do nothing, we will never solve this problem. We want to do something now because we’re already behind. So if there is an opportunity to help advance the clean energy agenda for the U.S., we should be doing it,” she said.

But not everyone agrees. The 13.2 million acres that make up the section of Idaho where the mine is located was the original home of a Native American tribe known as the Nez Perce or Nimiipuu.

Nakia Williamson said that after losing their land to the gold rush of the 1800s, the Nimiipu have given enough and do not want to give up the mine.

“We’ve had to sustain so much loss already with many other impacts that have happened to the land, the utter transformation of this landscape. And one more impact could be too much for us to sustain,” Williamson said.

The south fork of the Salmon River once contained the most thriving population of Chinook salmon in the world. Today, because of pollutants like those released from mining operations in the past, overfishing, and dams that block fish migration, it’s estimated only 1% of the salmon that used to run this section of the river remain.

“Our whole goal is to try to restore the fishery, bring the fishery back to get the salmon back to a sustainable level from an ecological standpoint and also from a harvest standpoint,” Emmit Taylor, another tribal leader, said.

The Nimiipuu are not the only ones pushing back on the Perpetua plan. Environmentalists believe if the mine is reopened, it will cause damage to the river for years to come.

“You know with the mining company and the area that they’ll be working in, and all of the different conditions that are there, it’s not a question of if a spill is ever going to occur, or if an accident’s ever going to occur, it’s a matter of when,” said Nic Nelson, executive director of Idaho Rivers United.

Perpetua does have many supporters, including politicians and locals who think the prospect of new jobs and a reconnected river is intriguing.

“I’m totally in favor of the mine. The mess that is left has to be cleaned up,” said Lynn Imel, a local who has lived in the area since 1968.

In 2020, the Environmental Protection Agency said it had “significant concerns” about harm to fish and that water treatment at the site would be needed forever.

Perpetua revised the plan and said they would shrink the footprint of the mine and lessen the impact on the environment. The review process of that new plan has just been extended for another two years. Idaho Rivers United and the Nimiipu consider that a victory, for now.

“We are accountable to this land. And we are the voice for this land. And so, it’s our responsibility to continue to advocate for those that no longer have the voice and has been imparted to us. And that’s the responsibility that we carry as Nimiipuu,” Williamson said.