i-80 Gold Sets Out Granite Creek Mine Plan

i-80 Gold has published a feasibility study for its Granite Creek Underground gold project in northern Nevada, outlining initial proven and probable mineral reserves of 556,500 ounces and an 8.5-year mine life. At a base gold price of $2,750 per ounce, the study estimates an after-tax net present value at a 5% discount rate of $118 million and undiscounted after-tax cash flow of $153 million. The operating mine is ramping up production and is expected to produce between 30,000 and 40,000 ounces of gold in 2026. The study also outlines average annual production of about 75,000 ounces from 2028 to 2032 after the planned refurbishment of the company’s Lone Tree Plant.

Study Economics And Production

The feasibility study is based on 2.20 million tonnes of proven and probable reserves grading 7.87 grams per tonne gold. It projects 485,000 ounces of recovered gold over the life of mine, with average recovery of 87%.

At an illustrative gold price sensitivity of $4,500 per ounce, the study estimates after-tax NPV of $598 million and undiscounted after-tax cash flow of $744 million. At $6,000 per ounce, those figures rise to $985 million and $1.2 billion respectively. The company stressed that the selected gold-price cases are illustrative sensitivities, rather than forecasts.

Richard Young, President & CEO at i-80 Gold, stated:

“The Granite Creek Underground Feasibility Study outlines robust project economics based on a significantly expanded mineral resource base, increased production rate, and longer mine life relative to the preliminary economic assessment ("PEA")(1) published in March 2025, despite over a year of mining depletion and only a modest drilling program focused primarily on infill drilling to support the FS.”

Expanded Resource And Reserves

The updated underground resource estimate incorporates approximately 36,470 metres of drilling from 164 core holes completed between 2023 and the end of 2025. Measured and indicated underground resources increased 229% from the 2025 preliminary economic assessment to 3.73 million tonnes grading 7.17 grams per tonne gold, containing 859,500 ounces.

Inferred resources total 0.89 million tonnes grading 7.06 grams per tonne gold, containing 202,800 ounces. The company attributed the reduction in inferred resources to infill drilling that converted part of the inventory to higher-confidence categories. Mineralisation is hosted in the Ogee, Otto and South Pacific zones.

Richard Young, President & CEO at i-80 Gold, stated:

“The drill program successfully delineated and expanded the mineralized zones, demonstrated continuity within the mineralized structures, and identified a number of additional prospective targets that suggest the potential for further mineral resource growth.”

Lone Tree Processing Plan

The study assumes third-party toll milling and trucking through to mid-2027, followed by stockpiling ahead of planned commissioning of i-80 Gold’s wholly owned Lone Tree autoclave and carbon-in-leach plant in the fourth quarter of 2027. From 2028, Granite Creek refractory ore is expected to be hauled to Lone Tree for processing.

For the 2028 to 2032 steady-state period, the study estimates cash costs of $1,827 per ounce and all-in sustaining costs of $1,915 per ounce, excluding the allocated Lone Tree refurbishment capital. Life-of-mine sustaining capital is estimated at $82.9 million, while the Lone Tree refurbishment allocation is $49.3 million.

Paul Chawrun, EVP & COO at i-80 Gold, stated:

“The Study also incorporates an optimized processing strategy which includes stockpiling the Project's sulfide and oxide ore ahead of the planned commissioning of the Lone Tree Plant in the fourth quarter of 2027. This strategy is expected to increase the amount of Granite Creek ore processed at the Lone Tree Plant at more favorable processing costs, while reducing reliance on third-party processing.”

Operational Development Continues

Granite Creek Underground is fully permitted and currently produces approximately 540 tonnes of ore per day. The feasibility study expects the mining rate to increase to approximately 900 tonnes per day at full production. The mine uses underhand drift and fill methods with cemented waste rock backfill.

Water-management work is also continuing, including installation of expanded sumps and higher-capacity pumps. A second water treatment plant has been constructed and is in commissioning, with expected additional surface water treatment capacity of approximately 3,500 gallons per minute.

Paul Chawrun, EVP & COO at i-80 Gold, stated:

“Successful infill and definition drilling within the South Pacific Zone closed mineralized gaps, improved continuity, and upgraded the existing mineral resources into higher-confidence categories, supporting a larger mineable inventory and longer mine life following over a year of mining.”

Next Technical Milestones

Exploration in 2026 is focused on infill drilling for reserve development and step-out drilling in the South Pacific, Rangefront, Otto and Ogee zones. The company also plans to evaluate the high-grade part of the CX Zone as an underground target through an anticipated multi-year programme beginning in 2027.

The National Instrument 43-101 technical report will be filed through SEDAR+, while the S-K 1300 technical report summary will be filed with the US Securities and Exchange Commission through EDGAR. i-80 Gold also expects to complete its feasibility-level technical study for the Cove underground project in the fourth quarter of 2026.