BOISE, Idaho (AP) — A Canadian mining company hoping to build a gold mine in Idaho west of Yellowstone National Park can resume exploratory drilling, the U.S. Forest Service said Friday.

The agency said it had approved Excellon Idaho Gold’s Kilgore Gold Exploration Project in the Caribou-Targhee National Forest in Clark County. Excellon Idaho is a subsidiary of Toronto, Ontario-based Excellon Resources Inc.

The project had been halted following federal court rulings in 2019 and 2020 concerning potential harm to Yellowstone cutthroat trout in a stream. The new drilling plan pulls water from a different stream officials say doesn’t contain Yellowstone cutthroat trout.

The company says the area contains at least 825,000 ounces (23.4 million grams) of gold near the surface, and potentially more deeper. The company said it is looking at possibly building an open-pit mine if exploration finds that the gold is mostly near the surface, or an underground mine if the gold is deeper.

Those types of mines would require additional approval from the Forest Service.

“As an Idaho native, I know how important it is to protect the animals, lands and waters we all cherish,” Phil Bandy, Excellon’s Senior Project Manager, said in a statement. “I am committed to collaborating with my fellow Idahoans to sustain a balance of economic development and natural resources stewardship.”

The Forest Service initially approved the exploration in 2018. But the Idaho Conservation League and the Greater Yellowstone Coalition filed a lawsuit in November 2018 contending the exploratory drilling could pollute groundwater and surface water.

The groups also said the drilling would harm grizzly bears, whitebark pine, Yellowstone cutthroat trout and Columbia spotted frogs.

The federal court ruled the Forest Service didn’t violate environmental laws in determining the exploratory drilling wouldn’t overly harm grizzly bears, whitebark pine or Columbia spotted frogs.

However, the court found the Forest Service hadn’t done an adequate analysis involving groundwater quality in the Dog Bone Ridge drainage, home to Yellowstone cutthroat trout. The trout are considered a sensitive species facing threats to population or habitat.

The new plan approved by the Forest Service says water for drilling at Dog Bone Ridge will now come from Beaver Creek rather than Corral Creek. The agency also said Excellon has added several monitoring sites associated with Dog Bone Ridge.

The company’s plan approved in 2018 included 10 miles (16 kilometers) of new roads and 140 drill stations.

The Forest Service in its approval on Friday said 10 drill sites had been built before the lawsuit halted the project, so the latest approval is for 130 drill sites. The surface disturbance associated with the new plan is 22 acres (9 hectares).

Josh Johnson of the Idaho Conservation League said the group was reviewing the Forest Service’s approval and keeping its options open.

“In general, we still have significant concerns regarding impact to water quality and wildlife from the proposed exploration project,” he said.

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This story has been updated to correct the name of a creek where water for drilling for the project would come from. It is Corral Creek, not Coral Creek.