Osisko Development Provides Infill Drilling Update on Its 13,000-Meter Lowhee Program at Cariboo Gold Project; Intercepts Include 596.40 g/t Gold Over 2.0 Meters from 6.1 Meters Downhole, Including 2,293.56 g/t Gold Over 0.5 Meters from 6.6 Meters Downhol

Executive Summary

• Osisko Development reports completion of ~11,025 m (≈80% of the planned 13 km) of infill drilling at 10‑m spacing in the Lowhee Zone, with an additional 5,043 m of new results since August 2025.
• High‑grade intercepts include a spectacular 596.40 g/t Au over 2.0 m (including 2,293.56 g/t Au over 0.5 m) and multiple >20 g/t Au intervals, confirming strong vein continuity and suggesting potential reserve upside.
• The program is on track to finish in early Q2 2026 after a brief suspension following an incident on Jan 23 2026; remaining assays and QA/QC are pending for the final ~12 % of planned meters.

Key Details

• Drilling Progress: 11,025 m total (≈80% of 13 km target); 5,043 m of new results added since August 2025.
• Overall Coverage: ~12.1 km (~88%) of the planned infill program completed; full assays pending for remaining holes.
• High‑Grade Intercepts (selected):
• BMU‑25‑132: 596.40 g/t Au over 2.0 m from 6.1 m depth (incl. 2,293.56 g/t Au over 0.5 m at 6.6 m).
• BMU‑25‑145: 21.67 g/t Au over 3.5 m from 96.5 m (incl. 135.44 g/t Au over 0.5 m at 99.5 m).
• BMU‑25‑174: 21.97 g/t Au over 2.5 m from 48.7 m (incl. 88.08 g/t Au over 0.5 m at 49.7 m).
• Additional Notable Intercepts:
• 90.95 g/t Au over 0.5 m (BMU‑25‑132, 7.6 m).
• 10.57 g/t Au over 4.8 m (BMU‑25‑157, 84.9 m) with a 95.61 g/t Au spike over 0.5 m.
• Multiple >10 g/t Au intervals across holes BMU‑25‑140, ‑145, ‑148, and others.
• Assay Methodology: HQ diamond core (63.5 mm) sampled whole‑core; assays performed by MSALABS (photon assay) and ALS Geochemistry (fire‑assay). QA/QC includes blanks, standards, and duplicate samples.
• Program Status: Drilling paused after Jan 23 2026 incident; resumption expected with program completion targeted for early Q2 2026. Remaining ~1,200 m of drill meters awaiting assay results and QC verification.
• Project Context: Lowhee Zone hosts 104,491 oz Au in probable reserves (≈5% of Cariboo total). The infill data will feed into updated block models, potentially expanding reserve stopes and informing production sequencing.

Notable Quotes

“This tighter drill spacing gives us a better understanding of vein corridor spatial geometries and local variability… the resulting information is expected to help refine infill drill requirements and production designs and sequencing in the Lowhee Deposit.” – Chris Lodder, President