Osisko Metals launches DPEX, confirms copper interval

Executive Summary

• Osisko Metals Inc. released initial results from the re-evaluation of the Porphyry Mountain deposit at its Gaspe Copper Project (GCP), confirming significant historic mineralization at depth.
• The company launched the Deep Porphyry Exploration Project (DPEX) for 2026, which will include deep drilling and reassaying of historic core to define a maiden NI 43-101 inferred mineral resource estimate by year-end 2026.
• Reassaying of historical drill hole DDH 30-0943 returned 852 metres averaging 0.95% CuEq, confirming the deposit remains open at depth and demonstrating potential for future ramp access from the Copper Mountain pit.

Key Details

• Drill Results (DDH 30-0943):
  • Interval: 998.0 metres to 1850.0 metres.
  • Length: 852.0 metres.
  • Average Grades: 0.70% Cu, 2.92 g/t Ag, 0.062% Mo.
  • Copper Equivalent (CuEq): 0.95%.
• Project Scope (DPEX):
  • Planned for 2026.
  • Activities: New deep drill program, reanalysis of historic drill core, and remodelling of historic information.
  • Objective: Outline a NI 43-101 inferred mineral resource estimate on the Porphyry Mountain Cu-Mo deposit by year-end 2026.
  • The program is conducted separately from the current resource evaluation work at GCP to provide preliminary information on the deposit's potential.
• Deposit Characteristics:
  • Located approximately 1,100 metres laterally northeast from the centre of the Copper Mountain pit.
  • Upper limit occurs at depths of approximately 1,000 to 1,200 metres.
  • Porphyry-style stockwork of Cu-Mo veins hosted by a separate porphyry intrusion.
  • Deposit is roughly cylindrical, ~500 metres in diameter, with a defined vertical length of at least 680 metres.
  • Historical holes stopped in mineralization at depths between 1,700 to 2,100 metres, indicating the deposit is open at depth.
  • Copper and molybdenum average grades are higher compared with the GCP Copper Mountain deposit.
• Future Plans & Context:
  • CEO Robert Wares anticipates the updated GCP Copper Mountain open pit will reach significant depths near the end of its mine life, potentially allowing for future ramp access to the deeper, higher-grade DPEX Porphyry Mountain deposit.
  • This follows the anticipated Q1 2026 release of an MRE update on the GCP Copper Mountain deposit and planned 2026 expansion drilling on Needle Mountain and Needle East zones.
• Analytical Methodology:
  • All analytical pulps from DDH 30-0943 grading >1% Cu are being analyzed for gold.
  • Cut-off: Average 0.30% CuEq lower cut-off over contiguous 20-metre intersections.
  • Assay provider: ALS Canada Ltd. (Sudbury preparation, North Vancouver analysis).
  • Method: Four-acid digestion followed by ICP-AES and ICP-MS for Cu, Mo, and Ag.
• Copper Equivalent Calculation:
  • Based on metal grades, estimated long-term prices ($4.25/lb Cu, $20.00/lb Mo, $24/oz Ag), estimated recoveries (92% Cu, 70% Mo, 70% Ag), and net smelter return values (86.5% Cu, 90.7% Mo, 75.0% Ag).

Notable Quotes

• "These very promising results launch our 2026 DPEX resource evaluation program at Porphyry Mountain... This should establish its true depth and reveal the full potential of the deposit, with the objective of releasing a maiden inferred MRE on Porphyry Mountain by the end of 2026. We anticipate that the updated GCP Copper Mountain open pit will reach significant depths near the end of its mine life, and this would potentially allow for future ramp access to the deeper, higher-grade DPEX Porphyry Mountain deposit." — Robert Wares, CEO