Nevada – September 21, 2026 -- i-80 Gold Corp. has completed a feasibility study for its Granite Creek Underground project outlining initial proven and probable mineral reserves of 556,500 ounces of gold at 7.87 grams per tonne across 2.20 million tonnes.
Measured and indicated resources jump 229% versus March 2025 preliminary assessment
The updated mineral resource estimate shows measured and indicated resources rising to 3.73 million tonnes grading 7.17 g/t gold, containing 859,500 ounces, a 229% increase from the PEA published in March 2025. Inferred resources fell 38% to 0.89 million tonnes at 7.06 g/t gold (202,800 ounces) as infill drilling converted material into higher-confidence categories. The estimate incorporates roughly 36,470 meters of drilling from 164 core holes completed between 2023 and the end of 2025.
Mine life extends to 8.5 years despite 15 months of depletion
The feasibility study projects a mine life of approximately 8.5 years, supported by drill results in the South Pacific Zone, even after accounting for 15 months of mining since the PEA. Relative to PEA mineable resources, roughly 65,000 ounces have been added to the mineral inventory net of depletion.
Base-case economics generate $118 million after-tax NPV at $2,750/oz gold
At a base case price of $2,750 per ounce, the project generates total undiscounted after-tax cash flow of $153 million and an after-tax net present value at a 5% discount rate of $118 million. At a spot sensitivity of $4,500 per ounce, cash flow rises to $744 million with an NPV of $598 million; at $6,000 per ounce, undiscounted cash flow reaches $1.2 billion with an NPV of $985 million.
Annual output to reach 75,000 ounces once Lone Tree Plant is commissioned
Annual gold production is expected to average approximately 75,000 ounces from 2028 through 2032, an increase of roughly 15,000 ounces per year versus the PEA, following commissioning of the company's wholly owned Lone Tree autoclave and carbon-in-leach plant. Cash costs during this five-year steady-state period are estimated at $1,827 per ounce, with all-in-sustaining costs of $1,915 per ounce, excluding Lone Tree refurbishment capital. Sustaining capital is estimated at $83 million, lower than the PEA despite deeper development and expanded infrastructure.
Third-party processing bridges operations until Lone Tree comes online in Q4 2027
Refractory and oxide ores will be processed by a third party through mid-2027, followed by roughly six months of stockpiling ahead of the fourth-quarter 2027 commissioning of the Lone Tree plant. "The Project is expected to be a key source of feed for our wholly owned Lone Tree autoclave and carbon-in-leach processing plant for many years to come,