i-80 Gold Corp. filed an 8-K on September 21, 2026, disclosing an updated Pre-Feasibility Study (PFS) for its Granite Creek Underground Project in Humboldt County, Nevada. The report, dated September 21, 2026, with an effective date of March 31, 2026, was prepared by SRK Consulting (U.S.), Inc., and other third-party qualified persons, as well as company employee Kenji Umeno. The study details the project's economics, mineral reserves, and resources, and notes that it supersedes a previous Preliminary Economic Assessment (PEA) published in March 2025.
According to the filing, the project is based on an assumed gold price of $2,750 per ounce. The study projects a mine life of 8.5 years, with an average annual gold production of 75.1 thousand ounces for the first five years (2028-2032) and 53.9 thousand ounces over the life of mine (LOM). The total gold contained in the processed ore is estimated at 556 thousand ounces, with an average recovery rate of 87 percent.
Financial metrics presented in the report include a pre-tax Net Present Value (NPV) of $138 million and an after-tax NPV of $118 million, both calculated using a 5 percent discount rate. The after-tax cash flow over the life of the mine is projected at $153 million. Total capital costs, including sustaining capital, Lone Tree Autoclave capital, and closure costs, are estimated at $144.9 million.
The updated mineral reserve estimate incorporates approximately 36,470 meters of drilling from 164 core holes conducted between 2023 and the end of 2025. The total proven and probable mineral reserves are estimated at 2,198 thousand tonnes with an average grade of 7.87 g/t Au, containing 556.5 thousand ounces of gold. The reserves are distributed across the Ogee, Otto, and South Pacific zones.
The report also includes an updated mineral resource estimate. The exclusive underground mineral resource statement includes 3,091 thousand tonnes of Measured and Indicated resources and 871 thousand tonnes of Inferred resources. Additionally, the filing details an open pit mineral resource statement for the CX, Mag, Pit A, and Pit B deposits, with total measured and indicated resources of approximately 33,525 thousand tonnes.
The company outlined its 2026 exploration program, which includes infill drilling to support reserve development and step-out drilling to expand mineralization in the South Pacific Zone, Rangefront, Otto, and Ogee zones. The report highlights the CX Zone beneath the historical CX pit as a near-mine target, noting previous high-grade intercepts including 18.0 g/t Au over 9.1 meters and 36.4 g/t Au over 9.1 meters. The company intends to evaluate the CX Zone as an underground target as part of a multi-year drill program planned to commence in 2027.
