Osisko Mining Turns Power on at Windfall Site - Seite 2

Permitting Process and IBA

The Windfall Environmental Impact Assessment review process by the COMEX is ongoing, and the Corporation is expecting WMG to receive the first round of questions in the coming months. In parallel, the Corporation expects to finalize the Windfall Impact and Benefits Agreement with the Cree First Nation of Waswanipi and the Cree Nation Government in 2024.

Qualified Person
The scientific and technical content in this news release has been reviewed and approved by Mr. Mathieu Savard, P.Geo (OGQ #510), President of Osisko, who is a “qualified person” (within the meaning of National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”)).

About the Windfall Gold Deposit
The Windfall gold deposit is located between Val-d’Or and Chibougamau in the Abitibi region of Québec, Canada. The mineral resource estimate on the Windfall Project (with an effective date of June 7, 2022 ) (the "Windfall Resource Estimate") and the mineral reserve estimate on the Windfall Project (with an effective date of November 25, 2022) (the "Windfall Reserve Estimate") are described in the technical report entitled "Feasibility Study for the Windfall Project, Eeyou Istchee James Bay, Québec, Canada" (the "FS Technical Report”) and dated January 10, 2023 (with an effective date of November 25, 2022). The Windfall Resource Estimate, assuming a cut-off grade of 3.50 g/t Au, comprises 811,000 tonnes at 11.4 g/t Au (297,000 ounces) in the measured mineral resource category, 10,250,000 tonnes at 11.4 g/t Au (3,754,000 ounces) in the indicated mineral resource category and 12,287,000 tonnes at 8.4 g/t Au (3,337,000 ounces) in the inferred mineral resource category. The Windfall Mineral Reserve, assuming 3.5 g/t operating, 2.5 g/t incremental, and 1.7 g/t development cut-off grade, comprises 12,183,000 tonnes at 8.06 g/t Au (3,159,000 ounces) in the probable mineral reserves category. The key assumptions, parameters, limitations and methods used in the feasibility study for the Windfal Project, including the related Windfall Resource Estimate and Windfall Reserve Estimate, are described in the FS Technical Report, which was prepared in accordance with NI 43-101. The FS Technical Report is available on SEDAR+ (www.sedarplus.ca) under Osisko’s issuer profile. The Windfall gold deposit is currently one of the highest-grade resource-stage gold projects in Canada and has world-class scale. Mineralization occurs in three principal areas: Lynx, Main, and Underdog. Mineralization is generally comprised of sub-vertical lenses following intrusive porphyry contacts plunging to the northeast. The resources are defined from surface to a depth of 1,600 metres, including the Triple 8 (TP8) zone. The reserves are defined from surface to a depth of 1,100 metres. The deposit remains open along strike and at depth. Mineralization has been identified at surface in some areas and as deep as 2,625 metres in others with significant potential to extend mineralization down-plunge and at depth.