US-based Perpetua Resources has broken ground on early works construction at its Stibnite gold project, advancing what will be the only domestic source of the critical mineral antimony.

The company said the start of construction follows the posting of $139-million in financial assurance and confirmation from the US Forest Service that all requirements of the 2025 record of decision (RoD) had been satisfied.

“Today, we break ground on the Stibnite gold project,” said Perpetua president and CEO Jon Cherry. “As America's answer to China's antimony export bans, we are focused on swiftly and safely bringing our antimony and gold project into development."

"After nine years of permitting, Stibnite can once again serve this country's national interest. We are proud of our work to bring this essential project online to provide critical resources while restoring an abandoned mine site. With our reclamation performance bond to reclaim the work we undertake at the Project site in place, we officially started early works construction today and are making good on our promises to Idaho and America.”

Perpetua received its final RoD in January 2025 and a conditional notice to proceed in September, indicating that all preconstruction requirements had been met. On October 17, the company posted the financial assurance – secured with cash on hand – to initiate early works, and expects to transition to non-cash arrangements once its full project financing package is finalised.

The project has been nearly a decade in permitting and has received $80-million in US Department of Defense funding. It is prioritised under the Trump Administration’s Transparency Project initiative and is regarded as central to the nation’s strategy for critical mineral independence.

The Stibnite gold project hosts the US's only known reserve of antimony. The project is also expected to be among the highest-grade openpit gold mines in the US, with 4.8-million ounces of gold reserves and forecast production of 450 000 oz/y over its first four years.

Beyond its economic contribution, Perpetua emphasised the project’s design to remediate historical environmental impacts at the former Stibnite mine, including reconnecting fish to native spawning grounds and restoring aquatic habitats in central Idaho.

Perpetua expects to create about 950 direct jobs during construction and 550 jobs during operations.

The company is also progressing project financing discussions, having received a preliminary project letter and indicative term sheet from the US Export-Import Bank’s (Exim) Make More in America and China Transformational Export Programmes, which could support up to $2-billion in debt financing. Final consideration by the Exim board is anticipated by spring 2026.