Osisko Metals Hits 1.36% Copper West of Gaspé Resource Boundary

Two drill holes sited more than 500 metres west of Gaspé Copper’s existing resource boundary have just returned some of the highest-grade intercepts of Osisko Metals’ entire 2026 campaign, and both sit entirely outside the deposit’s current mineral resource estimate. That distinction is the whole story.

Material outside the resource boundary contributes nothing to the published 1.83-billion-tonne figure. Not a single tonne, not a single pound of contained copper. These intercepts are additive rather than confirmatory, which is exactly why they set the stage for a resource update that could push the deposit westward.

Here is what the drill results actually tell you about where Gaspé Copper is heading: which intercepts carry the weight, why their position outside the model is commercially significant, and what evidence to watch before the next resource estimate lands.

The two intercepts that matter most from the September 28 release

The headline hole, DDH 30-1243, cut 211.5 metres averaging 0.59% copper, and inside that run sits a 28.5-metre sub-interval grading 2.31% copper and 11.8 g/t silver. The second, DDH 30-1236, returned 86.5 metres at 1.36% copper, including 18.0 metres at 4.53% copper and 23.3 g/t silver.

Both holes are classified as out-of-pit expansion, and both were drilled roughly 500 to 600 metres west of the April 2026 resource model, on the northern slope of Needle Mountain.

That location is the point. These blocks are not inside the current pit shell, so they book zero tonnes today. Every metre they represent is currently unaccounted for in the published estimate.

Compare that with the third hole in the release, DDH 30-1245, which returned 201.0 metres at 0.33% copper. That one is infill drilling inside the existing boundary; it firms up what is already counted rather than adding anything new. The out-of-pit classification is what separates confirmation from expansion.

The release as a whole covers 28 intercepts from 12 drill holes sited outside the resource boundary. The sub-intervals grading above 2% and above 4% copper tell you the expansion zone is not a thin low-grade skin wrapped around the known deposit; there is a genuinely high-grade core out there, and that changes the economic profile of any future pit extension.

Osisko Metals CEO Robert Wares has stated his confidence that the newly identified mineralised zones will be folded into a westward pit expansion in a forthcoming resource update, with results supporting the reclassification of former waste material on the pit slopes as resource.

For anyone weighing the current resource, the message is that the 1.83-billion-tonne figure may prove to be a floor rather than a ceiling.

Where these holes fit in Gaspé’s 2026 drilling campaign

Read the September 28 release on its own and it looks like a strong hit. Read it against the full 2026 chronology and it looks like a pattern being deliberately built.

The earlier Gaspé copper exploration results that drew attention to the deposit’s western extension were themselves building on a series of high-grade intercepts reported through mid-2025, a sequence that established the mineralisation trend now being confirmed and extended by the September 2026 holes.

Osisko has published drill results at a steady cadence since January, and the standout intercepts have carried the same out-of-pit expansion label again and again. The most recent releases make the point clearly. On 10 September 2026, the company reported DDH 30-1228 at 256.5 metres averaging 0.85% copper, an out-of-pit hole. Three weeks earlier, on 20 August 2026, DDH 30-1223 returned 312.5 metres at 0.56% copper.

Now the 28 September holes extend that run further west.

The key out-of-pit expansion results across the recent campaign line up as follows:

• 20 August 2026: DDH 30-1223, 312.5 m @ 0.56% Cu
• 10 September 2026: DDH 30-1228, 256.5 m @ 0.85% Cu
• 28 September 2026: DDH 30-1243, 211.5 m @ 0.59% Cu; DDH 30-1236, 86.5 m @ 1.36% Cu

Repeated high-grade hits west of the model since August tell you the mineralisation has lateral continuity rather than turning up as isolated pods. That distinction matters for whether an update adds meaningful tonnage or just a marginal top-up. Investors who follow only the single most recent press release consistently understate how much evidence has accumulated, and at what grade.

The April 2026 resource baseline these results are building beyond

All of this drilling is happening beyond a resource figure that is itself only months old. The current mineral resource estimate, announced on 14 April 2026, stands at 1,834 million tonnes measured and indicated at 0.27% copper (0.32% copper equivalent), containing roughly 10.8 billion pounds of contained copper. A further 238.8 million tonnes inferred grades 0.41% copper (0.46% copper equivalent), or about 2.16 billion pounds.

The estimate is pit-constrained under NI 43-101, meaning it counts only blocks that fall inside an optimised pit shell, and it applies a cut-off grade of 0.16% copper equivalent. A mineral resource estimate, or MRE, is the industry’s formal measure of how much metal a deposit is deemed to hold with reasonable prospects for economic extraction.

That April figure was itself a large step up from the earlier resource of 824 Mt indicated and 670 Mt inferred, which shows how quickly the deposit has grown, and that Osisko has executed major resource additions before.

Why drilling outside the pit boundary can directly expand a resource estimate

So what actually happens when a drill hole lands outside the pit shell and comes back with strong copper? On paper, nothing changes overnight. The block is still outside the economic boundary, so it still counts for zero. The mechanism by which it starts to count is worth understanding, because it is the difference between reading these numbers as raw metres and reading them as a signal about the next estimate.

A pit-constrained resource works like this: geologists build a three-dimensional block model of the deposit, then run a pit-optimisation algorithm over it using assumed copper prices, costs, and a cut-off grade. Blocks that fall outside the resulting economic pit shell are excluded from the resource, even if they are mineralised, because they sit beyond the point where extraction pays.

A mineral resource estimate, compiled under NI 43-101 or equivalent international codes, translates drillhole assays and block models into a formally classified figure that the market can value, and the methodology behind each update determines how much of a new drilling campaign converts into reportable tonnes.

Out-of-pit drilling attacks that boundary in three steps:

1. New drillhole data lands on blocks that were previously coded as waste or left unclassified because nobody had drilled them.
2. Where that data shows continuous mineralisation above the cut-off grade, those blocks can be reclassified from waste to inferred or indicated resource.
3. The pit-optimisation algorithm, such as the Lerchs-Grossmann method, is rerun over the updated block model, and the economic pit shell can extend outward to capture the newly proven material.

This waste-to-resource conversion on pit slopes is, according to technical consultancies including SRK and AMC Consultants that author NI 43-101 reports, one of the most powerful levers for resource growth in mature porphyry districts. When slope material once treated as waste converts to ore, the strip ratio falls and net present value can rise, because more payable copper comes out for a similar volume of rock moved.

The cut-off grade on the April 2026 resource is 0.16% copper equivalent. DDH 30-1243 graded 0.59% copper and DDH 30-1236 graded 1.36% copper, roughly three to eight times above that threshold.

That gap is the interpretive point. These are not borderline blocks that might just scrape into an update. They clear the economic cut-off comfortably, which tells you they are strong candidates for inclusion the moment the model is rerun.

What Gaspé’s scale means in the context of the current copper market

Step back from the drill core and the numbers describe a large system. Roughly 1.83 billion tonnes measured and indicated, holding about 10.8 billion pounds of contained copper, in a stable Canadian jurisdiction, with a resource base that is visibly growing. That combination lands differently against the current copper supply outlook than it would in a well-supplied market.

The supply picture is where the external analysis matters, because it does not come from Osisko. S&P Global’s “The Future of Copper” report projects significant supply gaps opening through the second half of the 2020s under accelerated energy-transition scenarios, and states that large, lower-grade porphyry deposits will be needed to help close them. The International Energy Agency identifies copper as a core metal for clean-energy infrastructure and electric vehicles, with demand set to grow strongly through 2030.

At the same time, Wood Mackenzie and CRU have documented persistent declines in average copper head grades across major producing regions such as Chile and Peru. As grades fall elsewhere, large-tonnage deposits gain strategic value even at modest grades, provided scale and metallurgy stack up.

Jurisdiction reinforces that. Québec has consistently ranked highly for policy attractiveness in the Fraser Institute’s Annual Survey of Mining Companies, which places Gaspé in a category that tends to draw strategic attention regardless of near-term copper price swings.

Open-pit copper resource growth in Quebec has not been confined to Gaspé; Pivotal Metals’ 42% resource addition at Horden Lake, announced in August 2026, demonstrates that the province’s broader copper geology is producing material step-change updates from targeted drilling programmes outside existing pit boundaries.

Development risks that investors need to weigh

None of that scale is de-risked, and the strategic case has real counterweights.

• Permitting: Québec’s Bureau d’audiences publiques sur l’environnement (BAPE) process involves detailed environmental review and public hearings, and large projects face lengthy timelines even in mining-friendly jurisdictions.
• Capital intensity: Porphyry-skarn projects at this scale typically demand multi-billion-dollar outlays for mills, tailings facilities, and infrastructure.
• Financing: For a mid-tier developer, funding a project of this size without a major-company partner raises real project-financing risk, a point analysts at BMO, RBC, and Scotiabank have repeatedly flagged for greenfield copper.
• ESG and social licence: Tailings design, water management, and meaningful engagement with First Nations and Inuit communities through impact-benefit agreements are prerequisites, not afterthoughts.

The supply-deficit thesis is widely covered. What matters for Gaspé specifically is whether its scale and location make it a credible long-term supply solution, and how far it still is from clearing these hurdles.

What the resource update will need to show for the expansion thesis to hold

The forward question is precise, not vague. Osisko has told the market a westward pit expansion is coming, but as of 28 September 2026 it has not published a calendar target for the next resource update. That means investors are, in effect, buying the expansion thesis ahead of the evidence.

That is not unusual mid-campaign, but it is the specific risk position to hold clearly in view: the direction is stated, the timing is not.

When the update does arrive, three things will show whether the thesis holds:

• Pit shell and tonnes: whether the optimised pit actually extends west, and how many new tonnes come with it.
• Grade of new material: how the newly classified blocks grade against the current 0.27% copper M&I average, and whether they clear the 0.16% copper equivalent cut-off comfortably.
• Confidence split: what proportion of the expansion material enters as indicated versus lower-confidence inferred resource.

The sustained pace of the 2026 programme, with releases running from January through September, suggests the next update will carry a substantial body of new data. The April 2026 estimate is the relevant precedent: it more than doubled the prior resource, which shows Osisko can deliver large additions when the drilling supports them. Whether this next one does the same is the open question.

For readers wanting to understand the classification framework in depth before the next update lands, our full explainer on mineral resource estimates covers how inferred, indicated, and measured categories are assigned and what evidence threshold each requires.

Investors who understand what the update needs to demonstrate can calibrate a position now, rather than reacting blind to the headline when it lands.

This article is for informational purposes only and should not be considered financial advice. Investors should conduct their own research and consult with financial professionals before making investment decisions.

Past performance does not guarantee future results, and forward-looking statements about resource expansion are speculative and subject to change based on drilling outcomes, market conditions, and company execution.