Osisko Gold Reports High-Grade Gold Intercepts at Proserpine Target Near Cariboo

• Osisko Gold Group confirmed high-grade gold intercepts at Proserpine, located seven kilometers southeast of the permitted Cariboo project in British Columbia.
• The initial diamond drilling program defined a broad mineralized footprint open in all directions, suggesting new open-pit mining operation to complement the existing underground project.
• Analysts note that while exceptional grades are noteworthy, the scale of the target remains the critical factor for future resource growth and valuation.
• Osisko has resumed drilling with three rigs, planning a further 26,500 meters to increase drill density and initiate first-pass drilling at new zones.

Osisko Gold Group Inc. reported initial diamond drilling results from the Proserpine regional greenfield target, located approximately seven kilometers southeast of the Cariboo Gold deposit in central British Columbia. The program, comprising 6,463 meters across 14 holes, confirmed high-grade gold structures and broader lower-grade zones that indicate the potential for open-pit mining. Drilling has expanded the known mineralized footprint at Proserpine to roughly one kilometer along strike by half a kilometer in width. Gold was encountered from near surface to depths beyond 400 meters, with mineralization remaining open in all directions. All holes that reached target depth intersected mineralization, underscoring the continuity of the system.

Standout results included hole PSP-26-004, which cut 4.6 meters grading 95.93 grams per tonne gold from 110 meters depth. This interval included a 50-centimeter segment grading 873 grams per tonne gold, highlighting the exceptional quality of the mineralization. Another hole, PSP-26-001, cut 8.6 meters grading 5.46 grams gold from 97 meters depth, further validating the high-grade nature of the target. National Bank Financial mining analyst Don DeMarco stated that these intercepts provide an encouraging proof-of-concept that Proserpine could become a meaningful contributor to future resource growth at Cariboo. While grades are exceptional, the more important takeaway is the scale, as drilling has defined mineralization over only a small portion of a much larger target.

What is the scale of the new Proserpine discovery at Osisko Gold's Cariboo project?

The Proserpine target represents a significant addition to Osisko Gold’s portfolio, potentially supporting future open-pit mining alongside a planned underground operation. The mineralization footprint has expanded to approximately one kilometer along strike by 500 meters in width, remaining open in all directions. Osisko plans to drill 26,500 meters at Proserpine using three rigs to increase drill density at Proserpine Southeast and begin first-pass drilling at Proserpine Northwest. This exploration underscores the prospect of a sizeable new gold system close to its permitted Cariboo project. The company’s primary focus remains advancing its 100%-owned, permitted Cariboo Gold Project, targeting both high-grade underground-style mineralization and potential open-pit, bulk mining opportunities.

The stock responded positively to the news, with analyst ratings reflecting a buy recommendation despite concerns regarding persistent losses and cash burn. Osisko Gold jumped 12.2% to $3.83 in Toronto, valuing the company at about $1.2 billion. The discovery validates the potential for future open-pit mining operations to complement the planned underground mine at Cariboo. Key intercepts include hole PSP-26-004, which cut 4.6 meters grading 95.93 g/t gold, including a high-grade 50-centimeter interval of 873 g/t. The stock rose 9% to $3.73 in another reporting instance, valuing the company at roughly $1.1 billion.

How does the Proserpine target complement the existing Cariboo underground operation?

Proserpine is one of several regional targets being tested as part of an exploration campaign aimed at identifying additional deposits. The Cariboo project, located in the historic Wells-Barkerville mining camp, includes a permitted underground mine and processing complex. A 2025 feasibility study envisions a scalable underground operation expected to produce about 1.89 million oz. gold over a 10-year life. The project hosts about 17.4 million measured and indicated tonnes grading 2.88 grams gold for contained metal of 1.61 million oz. gold. Construction is advancing while underground drilling continues to refine the mine plan.

The project holds 17.4 million measured and indicated tonnes grading 2.88 g/t gold, plus 18.8 million inferred tonnes grading 3.09 g/t. The after-tax net present value is estimated at $943 million based on a US$2,400 per oz. gold price. Osisko has entered into a Support and Benefits Agreement with the District of Wells for the Cariboo Gold Project, facilitating local community support and operational continuity. This agreement is part of the company's ongoing efforts to maintain positive relationships with local communities and stakeholders surrounding its primary asset in central British Columbia.

Osisko Gold Group announced that it has entered into a Support and Benefits Agreement with the District of Wells for the Cariboo Gold Project. The specific terms of the agreement focus on supporting local benefits and ensuring continued operational alignment with the District of Wells. The company also highlighted the completion of a name change from Osisko Development. Additionally, infill drilling at the Lowhee Zone supports existing geological and mine-planning assumptions. The discovery expands the known resource footprint and supports long-term growth potential for the Cariboo complex.

The initial drilling program completed 6,463 meters in 14 holes between February and May 2026. Osisko has resumed drilling with three rigs, planning a further 26,500 meters to increase drill density at Proserpine Southeast. The mineralization remains open in all directions, and all holes reaching target depth intersected mineralization. Analysts note that while the exceptional grades are noteworthy, the scale of the target remains the critical factor. Current drilling has only defined mineralization over a small portion of a much larger system.

The discovery supports the case for future resource growth at the Cariboo project. Early drilling at the Proserpine target has outlined a new mineralized system with exceptional grades, providing proof-of-concept for significant resource growth alongside the planned underground operation. The stock responded positively to the news, with analyst ratings reflecting a buy recommendation. Osisko Gold Group (TSX: OSG) announced that early drilling at the Proserpine target has defined a new mineralized system. This discovery supports the potential for future open-pit mining operations to complement the planned underground mine at Cariboo.