Copalito Drilling Returns 686 g/t AgEq as Strike Hits 11 km

Mercado Minerals has wrapped its inaugural 25-hole drill campaign at Copalito in northern Sinaloa, and the result reshapes what the project could become: two additional vein structures identified, total strike length up 37.5% from 8 km to 11 km, and the best single intercept at the project returning 686 g/t silver-equivalent (AgEq) over 3.5 metres.

These drilling results land against a backdrop of active investor interest in high-grade, vein-hosted silver projects across Mexico’s established silver belts. With only about 60% of known vein strike tested to an average depth of roughly 100 m, the programme has defined a system and mapped where to drill next, not where the story ends.

The project sits next to McEwen Mining’s El Gallo operation, a proximity that confirms established regional mineralisation and infrastructure precedent. What follows here is the analytical read an investor tracking Mexican silver exploration needs: what Copalito’s Phase I has genuinely established, and what Phase II is designed to test.

What the 25-hole programme found across seven vein structures

The programme’s backbone was Cinco Señoras, the vein that did the most consistent work across the campaign. Two of its standout intercepts returned 7.6 m at 434 g/t AgEq and 6.5 m at 372 g/t AgEq, and drilling extended its productive strike to approximately 800 m and depth to about 125 m.

Those are wide, repeatable intercepts, the kind that anchor a project rather than headline it. They tell you the system has at least one structure delivering mineable widths at consistent grade, which is the foundation any junior needs before chasing higher-grade outliers.

The programme tested seven vein structures in total: Cinco Señoras, SE 5 Señores, El Agua, El Pilar, El Pilar Sur, El Medio, and Chente. Grades and styles varied meaningfully across them.

Two shorter intercepts round out the picture without needing full table treatment:

• El Pilar Sur (COP-26-024): an 8.80 m wide vein and fault breccia confirmed
• El Medio (COP-26-022): 0.60 m at 88 g/t AgEq

El Agua delivers the programme’s headline number

Hole COP-26-012 at El Agua returned the best intercept at Copalito to date: 3.50 m at 686 g/t AgEq. To put that in context, underground vein-hosted silver mines in Mexico commonly report reserve grades in the roughly 150-400 g/t AgEq range, so a multi-metre intercept at nearly double the top of that band is a genuinely strong hit for an epithermal system.

Within that interval sat a higher-grade sub-section: 1.20 m at 34 g/t silver, 3.40 g/t gold, 19.0% lead and 21.0% zinc, equating to 1,120 g/t AgEq. That concentrated spike is the kind of nugget-style enrichment epithermal veins can produce, where a short zone carries a disproportionate share of the metal.

Copalito’s grade profile at El Agua sits comfortably within the upper range that epithermal silver systems can produce, where short high-grade sub-intervals reflect the focused fluid channelling typical of bonanza-style mineralisation in vein corridors.

The multi-metal makeup of El Agua and COP-26-019 matters for how you read grade quality. Copalito is not a single-commodity play, and its equivalency numbers carry real leverage to lead and zinc prices alongside silver and gold, which changes how sensitive the economics are to any one metal.

From six veins to eight, and 8 km of strike to 11 km: what the expansion metrics mean

The 25 holes did more than return grade. They redrew the map of the system itself, and the expansion is best understood as a progression rather than a pair of statistics.

Start with the vein count. The programme lifted the number of identified principal veins from 6 to 8, evidence that Copalito is a more structurally complex system than earlier mapping captured. More veins raise the probability that some combination of them adds up to a meaningful resource once systematically drilled.

Then the strike length. Cumulative mapped strike grew from 8 km to 11 km, a 37.5% increase, and the newly identified Renata vein alone accounts for roughly 1,150 m of that and is now a Phase II target.

Here is the before-and-after in plain terms:

• Vein count: 6 principal veins before, 8 after
• Strike length: 8 km before, 11 km after
• Strike coverage drilled: approximately 60% of known strike
• Average drill depth: approximately 100 m

That leaves roughly 40% of known strike untested, and the shallow 100 m average depth means the system is largely unexplored below surface. That untested portion is where the real questions about scale still sit.

Strike length and vein count are not resource proxies. Industry commentary consistently cautions that these early metrics do not capture true thickness, grade continuity, or economic cut-off, and can overstate potential if much of the mapped strike proves weakly mineralised or discontinuous.

For anyone tracking Copalito as an investment, that caution reframes the timeline. Because so much strike and depth remain untested, Phase II results will carry more weight than Phase I in determining whether the system scales to a meaningful resource. The programme just completed defined the footprint; the next one has to prove the grade holds across it.

Junior resource stock investing at the exploration stage involves assessing programmes like Copalito’s Phase I not as value confirmation events but as information milestones that progressively reduce geological uncertainty while leaving commercial viability dependent on subsequent drilling.

Phase II targets, regional context, and the variables that govern the next stage

Phase II’s priorities read directly off Phase I’s results. Mercado has confirmed follow-up drilling aimed at the structures and zones the initial campaign flagged as highest value.

The stated targets are:

1. Initial drilling on the newly identified Renata vein (approximately 1,150 m strike)
2. Expansion of higher-grade zones at El Agua
3. Expansion of higher-grade zones at El Pilar
4. Testing extensions at SE 5 Señores
5. Testing extensions at El Pilar Sur, plus step-out drilling on Phase I high-grade intercepts

The regional context sharpens the read. El Gallo, adjacent to Copalito, holds 199,000 oz Au measured and indicated resources, secured a Mexican federal EIA extension in December 2025, and has restart planning targeting Phase 1 mill construction in mid-2026 and a first gold pour in mid-2027. That confirms established infrastructure, regulatory precedent, and the mineralised character of the district around Copalito.

El Gallo also illustrates the risks that apply to any junior operating here:

Mexico’s silver sector regulatory environment has grown more demanding in recent years, with permitting timelines and environmental impact assessments adding material uncertainty to project schedules across the country’s established silver belts.

• Permitting: McEwen’s need for an EIA extension shows how evolving environmental rules can move timelines
• Community relations: El Gallo’s main access road was blocked by nearby communities until negotiations resolved it, a live example of social licence risk
• Security: parts of Sinaloa see organised crime activity that can raise costs and constrain fieldwork
• Financing: junior explorers depend on silver prices and investor sentiment to fund multi-phase drilling

One piece of information is notably absent. As of the August 2026 disclosures, Mercado had not published a Phase II meterage figure or budget. That gap matters, because without it you cannot yet model the programme’s scope or timing, and scope and timing are what determine how quickly Copalito can move toward a resource estimate.

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.

What Phase I established, and the standard Phase II must meet

Strip it back and the 25-hole programme did what a first campaign is designed to do. It confirmed mineralisation across multiple veins, returned above-benchmark grades at two structures, and expanded the system footprint enough to justify continued investment.

Headline intercepts El Agua (COP-26-012): 3.50 m at 686 g/t AgEq Cinco Señoras: 7.6 m at 434 g/t AgEq

Those numbers sit at or above the grades that underpin producing Mexican epithermal mines. Set against the full picture, 25 holes, 7 structures tested, 8 principal veins, 11 km of strike, roughly 60% drilled to about 100 m depth, Copalito reads as more than a grass-roots prospect and less than a defined resource.

That places the burden squarely on the next programme. Phase II has to begin answering what Phase I raised but could not resolve: grade continuity across the untested 40% of strike, extensions below 100 m, and whether Renata contributes at scale. For a silver-focused company advancing Copalito alongside San Dimas, the trajectory from here depends on that continuity holding up, not just on further intercepts in isolation.

For investors wanting a structured framework to assess whether a junior is genuinely advancing toward resource definition or simply cycling capital through successive drill campaigns, our dedicated guide to screening junior mining companies covers the specific indicators, cash burn benchmarks, and programme design flags that separate genuine exploration progress from promotional activity.

Past performance does not guarantee future results. Financial projections and exploration outcomes are subject to market conditions and various risk factors. Forward-looking statements are speculative and subject to change based on drilling results and company performance.