Killed twice in federal court, this copper mine outside Boise takes first big step forward
The U.S. Forest Service last week issued its final approval of a mining project near Boise that opponents say could threaten water and wildlife.
On Thursday, a cadre of Idaho environmental groups spoke out against the approval of the CuMo Exploration Project, a proposal from the Idaho Copper Corporation to allow mineral drilling in the Boise National Forest near Idaho City in search of copper, molybdenum and other mineral deposits.
If the drilling is successful, the company plans to pursue a large open-pit mine in the future.
Idaho Copper Corporation CEO Andrew Brodkey told the Idaho Statesman in a phone interview Thursday that the company stands by the environmental and safety analyses completed by the Forest Service as part of its approval process.
“They looked at every possible environmental impact, and they came to the conclusion that there were going to be no adverse effects on the environment from what we’re looking at here, which is a simple exploration drilling program,” Brodkey said.
Groups like the Idaho Conservation League, Idaho Rivers United, the Golden Eagle Audubon Society and more disagreed.
“Just the exploration alone poses threats to our water quality, recreation, traffic, public safety and wildlife — and it is a dangerous stepping stone to massive amounts of pollution in the Boise River headwaters from an open pit mine,” said John Robison, Public Lands and Wildlife Director with the Idaho Conservation League, in a news release.
Idaho mining project has years of history
The Forest Service signaled its initial approval in September, according to reporting from the Idaho Capital Sun, then held a mandatory 45-day objection period. It’s unclear why the final decision was delayed until last week. According to the Forest Service project page, the project is expected to move forward in May, but Brodkey said there are still state certifications and other minor plans to put in place before drilling begins.
The project, which was proposed in 2023, will build eight miles of roads and dozens of drill pads near Grimes Creek outside of Idaho City. Grimes Creek is a tributary of Mores Creek, which is a tributary of the Boise River.
“Assuming that there’s no lawsuit filed that would have some sort of an emergency appeal that would stop us from conducting our drilling, our plan is to drill this year,” Brodkey said.
It’s not the first time the mine was proposed — or faced pushback. According to previous Statesman reporting, this was the third version of the CuMo mine. Previous proposals were shut down by federal courts over threats to groundwater and a rare plant called Sacajawea’s bitterroot, according to reporting by The Associated Press and Idaho News 6.
Boise National Forest Supervisor Brant Petersen’s decision on the most recent proposal said the agency found no evidence of significant impact on the habitat, including the Boise River watershed and sensitive plant and animal species.
Brodkey said the “actual decision to put a mine in is years down the road.”
In their news release, the environmental groups said reaching that point would place the Boise River watershed “at unacceptable risk” and pointed to a February incident at a Zambia copper mine where tailings spilled into a river and created catastrophic pollution.
“If all goes to plan, this project will result in one of the largest open-pit mines in the Americas that has the potential to jeopardize one of Boise’s primary sources of drinking water,” said Nick Kunath, conservation director at Idaho Rivers United, in the news release.
This story was originally published March 21, 2025 at 4:00 AM.
