Corral Creek

Corral Creek Road is the southern approach to the mountains where the Kilgore project is located.

The Caribou-Targhee National Forest announced Friday its approval to allow a Canada-based mining company to conduct more exploratory drilling in the Centennial Mountains just northwest of Kilgore.

Excellon Resources was given the go ahead to drill about 130 exploratory sites and construct several miles of roads in an area near Kilgore, east of Interstate 15 in the Centennial Mountains near the Montana border. The operation is exploring the viability of an eventual gold mine.

The last Forest Service approval in 2020 was thrown out by legal action after a judge agreed with the Idaho Conservation League and Greater Yellowstone Coalition that the plan didn’t sufficiently protect water quality. The Forest Service reworked the plan this year and gave the mining company its OK.

“They have permission to drill pending approval of their mining plan,” said Sarah Wheeler, information officer for the Caribou-Targhee. “If they get permission they only have until Dec. 15 to do any exploratory drilling. They're in a tight time frame.”

Excellon has been approaching the Forest Service since 2018 and conducting exploratory drilling in the area. This latest project approval represents a major expansion of its plans. Its online website information about the project states its ultimate goal is to dig an open pit cyanide heap leach mine to extract gold from several million tons of rock. One company estimate places the value at close to $1.5 billion.

Josh Johnson, of the Idaho Conservation League, said his view is the new plan still doesn’t guarantee water quality despite the Forest Service reworking some requirements to protect nearby streams. He didn’t confirm whether the league would bring new legal action.

“The next step for us is to evaluate the final decision and decide how we want to proceed,” Johnson said.

“Part of the (mining) exploration is in an area called Dog Bone Ridge which drains into Corral Creek,” Johnson said. “It's a very important waterway in that part of the Centennials because it contains one of the only known populations of Yellowstone cutthroat trout in that region. It's the native trout species.”

Johnson said the Centennial Mountains are important to a host of stakeholders including ranchers, grizzly bears and elk, and drain into the eastern Snake River aquifer “which is a key source of drinking water for many people in eastern Idaho.”

“The court found that the Forest Service had not done a sufficient job protecting water quality the first time the permit came around,” he said. “Two or three years later we have still seen the same issues with water quality, the lack of baseline data, lack of ground water monitoring, things like that in this project. Water is the life blood of that area and it needs to be protected.”

Wheeler said the exploratory activities are only to see if a mine is going to be viable.

“Per the general mining law, individuals have the right to explore those mineral resources on federally administered lands,” she said. “If they can meet these environmental parameters per the mining law, it’s something they are able to do. It's not a full mining operation. If they are to find viable resources out there, the company would then be required to submit additional plans. That would be another (National Environmental Policy Act) process.”

Johnson said the short term concern is how the drilling will affect water quality, but he worries about Excellon's end goals.

"The long-term concern is that if this company Excellon finds enough gold resources in the Kilgore area, their stated intention down the road is to build an open pit cyanide heap leach gold mine which would fundamentally change the character of the Kilgore area and destroy the natural environment in that area," he said.