Toronto, June 5, 2023 – Osisko Mining Inc. (TSX:OSK. “Osisko” or the “Corporation“) would like to provide the following update on the ongoing forest fire situation affecting the communities in Abitibi and Eeyou Istchee James Bay, where the Windfall gold project is located. On June 2 and 3, 2023, Quebec’s Ministry of Natural Resource and Forests announced prohibitions regarding forest access on Crown lands, and closed forestry roads for reasons of public safety, given the current situation related to wildfires in the Abitibi and Eeyou Istchee James Bay regions.

John Burzynski, Chairman and Chief Executive Officer of Osisko Mining commented: “We have withdrawn our staff and continue to monitor our facilities remotely and on the ground in accordance with local directives. Our team is in constant communication with local and provincial authorities to coordinate all efforts in this difficult time. All personnel are safe, and the Windfall facilities are secure. While all activities at site are currently suspended, we do not anticipate any material impact on our business.”

Osisko will update the market in the event of any material change to Osisko arising in relation to the wildfires.

About Osisko Mining Inc.

Osisko is a mineral exploration company focused on the acquisition, exploration, and development of precious metal resource properties in Canada. Osisko holds a 50% interest in the high-grade Windfall gold deposit located between Val-d’Or and Chibougamau in Québec and holds a 50% interest in a large area of claims in the surrounding Urban Barry area and nearby Quévillon area (over 2,300 square kilometers).