Osisko Gold Group (OGG) investor relations material

Project overview and resource update

• $270 million spent pre-FID; 2 million oz reserves, 1.61 million oz measured/indicated, 1.8 million oz inferred, with 3.6 million oz not yet in the plan but expected to be included soon.

• Located near Quesnel and Prince George, with strong infrastructure and access to hydroelectric power, minimizing diesel reliance.

• Historic mining area with over 1,000 workings; only 4.4 km of 86 km strike length explored in detail, with 6 km more underway.

• CAD 990 million ($717 million) investment planned, with CAD 1.6 billion cash available and CAD 700 million free board for aggressive mine build and resource integration.

Construction progress and mine development

• Construction is 22% complete, with two portals underway and detailed engineering at 40%.

• CAD 325 million committed to procurement; mill and mining fleet already procured and on site.

• 350-person camp, waste dump, and water treatment plant nearly complete; significant earthworks finished.

• Mill site nearing completion, with concrete work about to start; second portal collaring in progress.

Production targets and financials

• Initial production target of 200,000 oz/year starting Q1 2029, with plans to double to 400,000 oz/year through conversion drilling.

• Ten-year mine life, all-in sustaining cost of $1,163/oz, and free cash flow of CAD 362 million/year at $3,700 gold.

• NPV ranges from CAD 2.3 billion at $3,570 gold to CAD 3.8 billion at $4,300 gold; IRR between 34.7% and 43%.

• Payback period of 1.8 years; annual free cash flow first five years at CAD 642 million.