Name of the Project
Stibnite gold project.

Location
Central Idaho, in the US.

Project Owner/s
Mining exploration and development company Perpetua Resources Corp.

Project Description
The project is expected to be one of the highest-grade openpit gold mines in the US. It is designed to redevelop the abandoned Stibnite mine site for gold, silver and antimony, while providing environmental restoration for the dormant site.

The project contains an estimated 4.8-million-ounce gold reserve and is expected to produce 450 000 oz/y of gold over the first four years of production.

In addition, the estimated 148-million-pound antimony reserve is the only identified antimony reserve in the US, and is expected to supply an estimated 35% of the country’s demand in the first six years of operation. 

Antimony is a listed critical mineral for its role in technology, defence and energy products.

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

Net Present Value/Internal Rate of Return
The project is expected to provide an estimated 550 jobs for rural Idaho during operations.

Capital Expenditure
Not stated.

Planned Start/End Date
The US Forest Service approved the mine plan in January 2025, in accordance with the country’s National Environmental Policy Act.

This final record of decision (RoD) concludes an extensive eight-year process of investigation, analysis, consultation and public engagement.

The approval enables Perpetua to proceed towards a final construction decision, including securing remaining federal and state permits, and project financing.

Latest Developments
Perpetua Resources has started early works construction, advancing what will be the only domestic source of the critical mineral antimony.

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 RoD had been satisfied.

Perpetua received its final RoD in January 2025 and a conditional notice to proceed in September 2025, 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 noncash arrangements once its full project financing package is finalised.

The project has been nearly in permitting for nearly a decade and has received $80-million in US Department of Defense funding. It is prioritised under US President Donald Trump’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 has 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.

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. This could support up to $2-billion in debt financing. Final consideration by the Exim board is expected in the first half of 2026.

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Perpetua Resources Corp, tel +1 208 901 3060 or email info@perpetuacorp.us.