Osisko Development intercepts 13.19 g/t Au over 3.60 m at Cariboo Gold Project

HIGHLIGHTS 8,971 m of new surface exploration drilling designed to test near mine potential at depth and in under-drilled gap zones between defined deposit footprints. Approximately 65% of drilling transected areas outside the Cariboo Gold deposit. Highlight intercepts from outside the footprint of the current mineral resource across multiple zones on strike, include: 13.19 g/t Au over 3.60 m at 596 m vertical depth, 6.40 g/t Au over 6.30 m at 326 m vertical depth (including 40.60 g/t Au over 0.50 m, 19.10 g/t Au over 0.70 m, and 4.56 g/t Au over 0.70 m ) , 6.17 g/t Au over 7.10 m at 517 m vertical depth (including 73.20 g/t Au over 0.50 m, 10.40 g/t Au over 0.50 m, and 2.21 g/t Au over 0.50 m ) and 28.90 g/t Au over 0.50 m at 718 m vertical depth.

Results to date confirm the presence of high-grade mineralization at depth and reinforce the strong potential for upside within under-tested gap zones and below the current Cariboo Gold deposit footprint, which extends to an average depth of approximately 350 metres. 5 drill rigs continue operating at surface systematically testing targets down-dip of the current Mineral Resource to a maximum vertical depth of up to 800 metres. MONTREAL, July 08, 2026 (GLOBE NEWSWIRE) -- Osisko Development Corp. (NYSE: ODV, TSXV: ODV) (" Osisko Development " or the " Company ") is pleased to announce new drilling results from eleven (11) surface diamond drill holes that were completed as part of an ongoing deeps and near mine gap infill exploration program at the Company's permitted, 100%-owned Cariboo Gold Project (" CGP " or the " Project "), located in central British Columbia, Canada. Chris Lodder, President, stated , "We are encouraged by the initial results of the surface exploration