Perpetua secures federal OK for Stibnite mine in Idaho

[Ben Graham]

Perpetua Resources Corp. (Nasdaq: PPTA; TSX: PPTA) has received final federal approval to begin construction at its Stibnite project in Idaho, positioning the company to deliver the United States’ only domestic supply of antimony along with significant gold production.

The US Forest Service issued a conditional Notice to Proceed on Friday, confirming that Perpetua had satisfied all requirements outlined in the January 2025 Record of Decision. The only remaining step before initial construction is posting financial assurance bonds agreed upon with the US Forest Service, Idaho Department of Lands, and the U.S. Army Corps of Engineers. The company expects to finalize bonding in the coming weeks, with construction slated to start by October.

Shares of Perpetua rose 1% on Friday, trading at $17.59 in New York and giving the company a market capitalization of about C$1.89 billion.

Strategic critical mineral supply

The Stibnite project is expected to begin commercial production by 2028, with a 15-year mine life that could supply more than 100 million pounds of antimony, meeting over 35% of US annual demand.

Antimony is a metal vital to defense applications, including munitions, as well as renewable technologies like solar panels. Currently, the US has no domestic production of antimony and relies heavily on imports, primarily from China.

“This is a monumental milestone,” said Jon Cherry, President & CEO of Perpetua Resources. “After eight years of review and over $400 million invested, it is finally time for the Stibnite Gold Project to deliver for America. We are ready to bring Stibnite back to life as a national strategic asset.”

The project will also produce roughly 450,000 ounces of gold annually, providing a dual revenue stream. Proven and probable reserves at the site include 148 million pounds of antimony and more than 6 million ounces of gold.

Last April, the US Export-Import Bank signaled support for the project with a letter of interest for up to $1.8 billion in financing, which remains under review.

The project has backing from billionaire investor John Paulson and has also drawn political attention in Washington, particularly after China’s decision last year to block exports of antimony to the US.

Environmental restoration and local concerns

Perpetua has emphasized the project’s dual focus on mineral production and environmental restoration. The final mine plan was redesigned to reduce the project footprint by 13%, improve stream and wetland conditions, and reconnect fish habitats.

Still, the project has faced opposition from Idaho’s Nez Perce tribe, which has raised concerns over potential impacts on salmon populations in the region.

Located in Idaho’s Stibnite-Yellow Pine district, about 222 kilometers northeast of Boise, the site was once a critical supplier of antimony during World War II.

the project hosts 104.6 million proven and probable tonnes grading 1.43 grams gold per tonne and 0.064% antimony for 4.8 million oz. gold and 148 million lb. antimony, according to the feasibility study.