Osisko Development provides infill drilling update on Lowhee Program

Osisko Development (ODV) announced new infill drilling results from its ongoing 13,000-meter program on 10 meter drill spacing that commenced in August 2025 in the Lowhee Zone of the Company’s permitted, 100%-owned Cariboo Gold Project, located in central British Columbia, Canada. The first three fans of this program consisted of approximately 2,279 meters of underground infill drilling. Chris Lodder, President, stated, “We have observed good continuity consistent with modelled vein zones and planned stope shapes with these initial results. The presence of high-grade composites within and adjacent to modelled reserve stopes is encouraging and highlights the value of systematic underground infill drilling. The success we are seeing underscores the potential and prospectivity of delineating new zones and expanding existing ones near planned infrastructure, which could be drilled off and incorporated into a future mine plan. The comprehensive 13,000-meter drill program is designed to deliver important data for resource modelling, mine planning, and optimization of production stope design. We look forward to providing further updates as drilling progresses.” DRILL ASSAY HIGHLIGHTS: Select assay photon assay highlights include: 45.24 grams per tonne (“g/t”) gold (“Au”) over 3.0 m in hole BMU-25-075, including: 233.92 g/t over 0.5 m, and 35.19 g/t over 0.5 m; 41.17 g/t over 2.1 m in BMU-25-065, including:142.56 g/t over 0.5 m, and; 19.20 g/t over 0.6 m, and 5.88 g/t over 0.5 m; 16.36 g/t over 4.6 m in BMU-25-079, including: 111.75 g/t over 0.5 m, and 25.03 g/t over 0.6 m, and 5.17 g/t over 0.5 m; 38.92 g/t over 1.5 m BMU-25-073, including: 113.06 g/t over 0.5 m, and 3.17 g/t over 0.5 m; 9.87 g/t over; 3.95 m in BMU-25-085, including: 22.84 g/t over 0.6 m, and 13.78 g/t over 0.85 m, and 16.04 g/t over 0.5 m, and 5.22 g/t over 0.5 m, and 4.00 g/t over 0.5 m; 5.67 g/t over 6.0 m in BMU-25-064, including: 17.95 g/t over 0.5 m, and 8.45 g/t over 1.0 m, and 11.38 g/t over 0.5 m, and 8.46 g/t over 0.5 m, and 6.99 g/t over 0.5 m, and 4.36 g/t over 0.5 m; 7.06 g/t over 4.5 m in BMU-25-067, including: 39.00 g/t over 0.5 m, and 15.96 g/t over 0.5 m, and 3.82 g/t over 0.5 m; 8.97 g/t over 3.5 m in BMU-25-078, including: 59.94 g/t over 0.5 m; 9.18 g/t over 2.6 m in BMU-25-083, including:23.51 g/t over 0.5 m, and7.20 g/t over 1.0 m, and 7.87 g/t over 0.6 m; 3.36 g/t over 7.0 m in BMU-25-071, including: 14.78 g/t over 0.5 m, and 11.19 g/t over 0.5 m, and 5.75 g/t over 0.5 m, and 3.29 g/t over 0.5 m, and 4.03 g/t over 0.5 m, and 3.88 g/t over 0.5 m