Inside Kootenay Silver’s Columba: 54 Moz Resource and What Comes Next

Large primary silver deposits are becoming genuinely hard to find. Existing mines are ageing, discovery rates for high-grade vein systems have thinned out, and any project that can credibly point toward scale draws attention fast. That scarcity is the backdrop for everything that follows.

The Kootenay Silver Columba Project in Chihuahua, Mexico sits directly in that gap. A 60,000-metre drill programme crossed its halfway mark in late September 2026, and the company is fully funded to see it through. This is not a project waiting for capital. It is a project actively testing whether its known resource is the whole story or just the beginning.

Here is the distinction that matters most as you read on. Not all exploration drilling carries the same weight: stepping out along a proven vein is a different bet from hunting an entirely new structure nobody has drilled before. What follows gives you a clear framework for evaluating both the geological upside and the inherent risks as Columba transitions from a defined resource into a broader district-scale target.

Decoding the Columba hydrothermal system

Start with the rock itself, because the geometry of this deposit is what shapes every number the company reports.

Columba is an epithermal silver system. In plain terms, that means silver-rich hot fluids rose through fractures in the host rock over geological time, cooling and depositing metal along the way. Where those fluids were most concentrated and boiling occurred, they built narrow, ultra-high-grade cores. Where fluids leaked sideways into the surrounding brittle rock, they created a broader web of veinlets called stockwork.

Epithermal silver systems form when hydrothermal fluids rise through crustal fractures and deposit metal as pressure and temperature drop, a process that produces the sharp grade contrasts between vein cores and surrounding stockwork that make these deposits simultaneously exciting and difficult to model at early drill spacings.

That two-part structure is the key. The high-grade core grabs the headline, but the stockwork halo around it is what builds volume.

At Columba, the primary vein cores average roughly 5 to 6 metres wide. Around them, stockwork mineralisation extends up to 10 metres on either side of the main vein, widening the effective mineralised zone well beyond the core. This is why a single drill hole can return both a sub-metre hit of extreme grade and a tens-of-metres interval of moderate grade in the same intercept.

The system is not one vein. It is a structural corridor holding multiple parallel targets, including the D, F, and B/Lupe veins. Three features define how it behaves:

• Ultra-high-grade cores: narrow zones where boiling concentrated silver, producing grades up to 4,040 g/t silver over sub-metre widths.
• Broad stockwork halos: lower-grade veinlet zones flanking each core, adding tonnage across tens of metres.
• Repeating structural traps: the same core-plus-halo geometry recurs at depth and along parallel structures, which is what gives the corridor its scale potential.

Here is what this geometry tells you as an investor. A dramatic half-metre hit of 1,500 g/t silver is exciting, but the 58-metre halo of moderate-grade mineralisation surrounding it often matters more to the eventual economics, because tonnage, not just grade, determines whether a project becomes a mine.

Why stockwork mineralisation drives tonnage

Stockwork forms when mineralising fluid leaks out of the main structure into the fractured rock beside it, filling countless small cracks with veinlets. It is lower grade than the core, but it occupies far more volume.

That volume is what makes the deposit scalable. Because the mineralised zone is wide rather than a single knife-edge vein, each metre of strike length adds meaningful ounces. It is a far more efficient way to grow total contained silver than chasing narrow high-grade shoots alone.

The 54.1 million ounce baseline

Before considering any speculative upside, it helps to know exactly what is already documented. Columba has a maiden inferred resource, and the numbers are firm.

With an effective date of 29 May 2025 and a supporting NI 43-101 technical report filed on 1 August 2025, the estimate stands at 54.1 million ounces of silver contained within 5.92 million tonnes grading 284 g/t silver. It also carries by-product credits of 25.2 million pounds of lead and 65.6 million pounds of zinc.

One detail deserves emphasis. These are pure silver ounces, not silver-equivalent figures inflated by adding in the value of base metals. When a company quotes silver-equivalent, it bundles lead and zinc into the headline number. Columba’s 54.1 million ounces is the silver alone, which makes the grade and scale more directly comparable to peer projects.

Against the global peer group, many early-stage vein-hosted silver projects report grades in the 150 to 300 g/t range. Columba’s 284 g/t places it near the top of that band, marking it as a high-grade, mid-scale asset.

This baseline gives you a hard floor for valuation modelling. It confirms Columba already possesses the critical mass to warrant attention from mid-tier producers, entirely separate from whatever the current drilling delivers. Everything beyond this figure is the speculative part of the story.

The structural silver supply deficit running through the mid-2020s is one reason why high-grade primary projects like Columba attract attention disproportionate to their current resource size: new mine supply is genuinely scarce, and producers seeking replacement ounces have few credible targets to acquire.

Inside the strategic pivot of the 60,000-metre programme

The current campaign is where the tension lives. Drilling began in August 2025 with two diamond core rigs, originally scoped at 50,000 metres and then expanded by 10,000 metres to 60,000 metres in March 2026. As of 22 September 2026, more than 30,000 metres are complete and 51 holes have been reported.

The programme splits into two phases. The first 25,000 to 30,000 metres target the known resource bodies in the D, F, and B/Lupe veins, thickening and lengthening what is already defined through step-out drilling at roughly 100-metre spacings. This is the lower-risk work: extending mineralisation the company already understands.

The most recent results validate that groundwork. On 22 September 2026, Kootenay reported hole CDH-26-258 returning 232 g/t silver over 24 metres in the Lupe Vein, including a sub-interval of 1,520 g/t over 0.55 metres. The same hole delivered a hanging-wall stockwork hit of 58 metres grading 51 g/t silver, exactly the core-plus-halo pattern the system is known for.

These intercepts confirm that high-grade shoots persist at depth, which is precisely the evidence needed to justify drilling deeper and, eventually, wider.

The risk and reward of testing new structures

The second phase is where management steps out into the unknown. Rather than only extending proven veins, later drilling targets untested “look-alike” structures within the same hydrothermal corridor, based on the reasoning that if multiple veins share the same orientation, undrilled parallel structures could host comparable mineralisation.

Structural corridor targets rely on the same geological reasoning as Columba’s multi-vein strategy: where major crustal faults intersect or run parallel, the resulting permeability can channel mineralising fluids into multiple discrete vein systems, each with its own grade distribution, rather than concentrating everything into a single shoot.

This is a deliberate change in risk appetite. Infill drilling on known veins is the safe accumulation of ounces: it upgrades confidence and modestly grows tonnage. Drilling a blind structure is high-risk, high-reward. A discovery could add an entirely new resource domain and deliver a step-change in total ounces.

The cost side is real. If the structural model is wrong, the drill returns barren rock and the money spent is gone regardless of outcome. That is the trade-off management has chosen to make.

What this pivot tells you is straightforward. The company is hunting for a genuine expansion in resource size, not settling for marginal upgrades. A successful parallel vein could move the project toward the 100-million-ounce threshold that market commentators have raised, which is a materially different investment proposition from the current baseline.

Evaluating inferred ounces in a primary silver market

Now the sober part. Every ounce discussed so far sits in the inferred category, and that classification carries strict limits you need to respect.

Under Canada’s NI 43-101 rules and CIM Definition Standards, an inferred resource is the lowest-confidence category, estimated from limited data with significant uncertainty in both grade and tonnage, and it generally cannot serve as the sole basis for a definitive feasibility study.

Under Canada’s NI 43-101 rules and CIM Definition Standards, an inferred resource is the lowest-confidence category. It is estimated from limited data, with significant uncertainty in both grade and tonnage. Critically, inferred resources cannot be converted directly into mineral reserves, and they generally cannot serve as the sole basis for a definitive feasibility study.

To upgrade portions of the resource to indicated or measured status, the company must complete substantial additional infill drilling. Only then can those ounces support detailed economic studies.

The geology compounds this uncertainty. Vein-hosted systems show strong local grade variability, where very high-grade pockets sit right beside lower-grade material. Modelling from 100-metre drill spacings can smear or miss high-grade shoots entirely, meaning early estimates can revise in either direction as more holes are drilled.

Kitco’s July 2026 commentary framed Columba as a “potential 100 Moz silver system,” pointing to the combination of high grades and continued success drilling deeper and laterally along the veins.

Treat that figure as it is intended: a projection of what continued exploration success could deliver, not a resource on the books today.

Here is the discipline this requires. You should heavily discount these exploration-stage ounces in any portfolio model, because inferred resources carry immense geological uncertainty and cannot be treated as guaranteed future production. This is the institutional perspective, and it is what protects you from pricing exploration risk as if it were already resolved.

Setting your expectations for the next phase of discovery

Columba currently offers two distinct things at once. There is the 54.1-million-ounce inferred foundation, high-grade and already at mid-tier scale, and there is the speculative upside of a drill programme still testing whether the corridor holds more.

As the final assays from the 60,000-metre programme arrive, a few things are worth watching:

• Whether step-out holes continue to extend the known D, F, and Lupe veins at grade.
• Whether the wildcat holes into untested structures return meaningful mineralisation.
• Whether results support an eventual updated resource estimate, and how far it moves the total.

What separates Columba from a typical single-asset exploration story is its multi-vein, district-scale setting. That structure gives it more pathways to grow than a lone vein ever could, though every one of those pathways still has to be proven by the drill.

Investors modelling Columba’s potential economics at various resource sizes should review our deep-dive into silver price forecasts through 2030, which covers industrial demand trajectories, monetary policy scenarios, and the supply response lag that shapes long-run price floors.

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 these statements regarding future exploration outcomes are speculative and subject to change based on market developments and drilling results.