A federal appeals court is weighing the question: at what point can regulators put the brakes on a proposed mine? T hat question came up in a legal fight between a coalition of tribes and environmentalists challenging a controversial mine development near Haines.

Chilkat Indian Village of Klukwan and a coalition of green groups lost their first round in court when they challenged a Bureau of Land Management permit for a Canadian mining company’s exploration project.

Constantine Metal Resources is in the advanced stages of exploration for a copper-zinc-silver-gold mine. Surrounding residents are divided between the promise of local jobs and the concern that mine waste and runoff could pollute the Chilkat River.

The tribe and Southeast Alaska Conservation Council, Lynn Canal Conservation and Rivers Without Borders filed suit in 2017 saying BLM’s lease permit for mineral exploration should’ve triggered a full environmental review of what a mine might be like.

But a district court ruled against them, saying mineral exploration does not always lead to actual mining.

Now the San Francisco-based 9th U.S. Circuit Court of Appeals is weighing the case. During Wednesday’s oral arguments, the plaintiffs argued BLM must consider the impact of hardrock mining before granting an exploration permit.

Earthjustice attorney Erin Whalen told KHNS that once a permit is in hand it’s almost impossible to deny miners their right to mine. That’s due to a landmark 19th century law that still guides mineral extraction on federal land.

“It’s the look before you leap, do it before it’s too late requirement,” she said.

“The way that the law works under the 1872 mining law is that if exploration proceeds far enough, and they’re able to demonstrate essentially a valuable discovery that they could mined profitably, then the  the people who are leasing to Constantine would acquire a property right or right to extract minerals under that 1872 Mining Law.”

The claim holder’s Juneau attorney Jim Clark doesn’t disagree with that premise. In a hearing before the three-judge court, he used that same logic to argue against requiring a full-blown national environmental policy⁠—NEPA⁠—review.

“If the agency can’t say no, then what’s the point of NEPA analysis? Because even if it develops NEPA analysis, it can’t act on that analysis. And that’s what the situation is here,” he said.

“Since they can’t say no to exploration because you may find something, then they can’t act on any information they might find and NEPA isn’t necessary here.”

Federal attorney Ellen Durkee says BLM only has to consider the effects of exploration when granting the land use permit. Mining isn’t connected, she argues.

It’s now up to the 9th circuit to decide at what point in mineral exploration the development of a mine becomes unstoppable.

That decision could determine whether the Palmer Project can proceed.