Midnight Sun Mining Delivers Major De-Risking at Dumbwa Copper Discovery - New 99-Hole Release Highlights Scale and Continuity in the Zambian Copperbelt

In one of the largest single assay releases in recent junior mining history, Midnight Sun Mining has dramatically de-risked its Dumbwa target, establishing a significant copper system directly analogous to Barrick's giant Lumwana mine and surrounded by some of Africa's largest copper operations.

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Midnight Sun Mining Delivers Landmark 99-Hole Assay Release at Dumbwa Copper Discovery, Zambia – A Major New System Emerges in the Heart of the Copperbelt

May 16, 2026 Midnight Sun Mining (TSX-V: MMA, OTCQX: MDNGF) has taken a major step forward in one of the most prospective copper districts on Earth. In a single, comprehensive news release, the company delivered assay results from 99 drill holes at its Dumbwa (Dumba) discovery in Zambia’s Zambian Copperbelt — a rare scale of data that dramatically advances the project from early-stage target to a confirmed, large-scale copper system with strong geological continuity. Vice President of Business Development Adrian O’Brien joined Bill Powers on Mining Stock Education to walk through the results, describing the moment as a “major moment” for the company and confirming what many in the industry suspected: Midnight Sun has a significant copper discovery on its hands in one of the world’s top copper jurisdictions.

Context: The Zambian Copperbelt – Among the Greatest Copper Provinces on the Planet

The Zambian Copperbelt is home to some of the largest and highest-grade copper deposits ever discovered. Neighbouring operations include:

• Barrick Lumwana — 1.6 billion tonnes at ~0.5% Cu (recently expanded significantly).

• First Quantum’s Kansanshi — one of Africa’s largest copper-gold mines.

• Ivanhoe Mines’ Kamoa-Kakula — the world’s highest-grade major copper mine and one of the largest new discoveries in decades.

Midnight Sun’s Dumbwa project sits squarely in this elite neighbourhood. The company controls a 20 km long copper-in-soil anomaly — an exceptionally large geochemical footprint that has been built up through multiple generations of sampling. Historic drilling by First Quantum provided early encouragement, but Midnight Sun’s systematic modern program is now revealing the true scale and continuity of the system.

What the 99-Hole Release Reveals

This is one of the largest single batches of drill results released by a junior explorer in recent memory.

Key takeaways from the assays and O’Brien’s commentary:

• Strike Continuity Confirmed: Assays now cover 5.3 km of drilled strike length on the Phase 1 target (part of the larger 11+ km initial focus area).

• Large Tonnage, Bulk-Mineable System: Dumbwa is shaping up as a very large tonnage copper deposit with variable but economically interesting grades. It is not a uniform 0.5% super-pit, but a zoned system with higher-grade cores (including intercepts such as 93 m at 4% Cu) flanked by moderate-grade halos — typical of major Copperbelt deposits.

• Strong Geological Analogy to Lumwana: O’Brien emphasized that Dumbwa and Lumwana are “geologically one and the same.” Both show stacked sulphide lenses, similar mineralization styles (massive chalcocite, bornite, chalcopyrite), and comparable structural setting.

• Surface Indicators Validate the Model: Copper clearings (areas where high copper levels in soil kill vegetation) align strongly with mineralization. The company is actively drilling these high-priority zones.

• Systematic Approach Paying Off: Midnight Sun is drilling on a tight grid (every 50 m across strike, 100–200 m along strike) — an ultra-methodical program designed to build a “bulletproof” dataset for future resource estimation and de-risking.

The results come after laboratory QA/QC delays that pushed back news flow. Those issues have now been resolved, with assays split between SGS and Intertek for faster turnaround. The company expects steady news flow through the remainder of 2026.

Exploration Strategy and Funding Position

Midnight Sun is executing a disciplined Phase 1 program on the southern ~11 km of the anomaly. With four drill rigs turning, the company is advancing at an impressive pace. O’Brien noted that drilling costs in Zambia are highly competitive (~C$160 per metre all-in, including assays), allowing aggressive meters with a strong cash position. The company also holds the Kaseba oxide copper deposit — a near-surface, high-grade resource (2.33 Mt at 1.41% Cu indicated) that is being advanced toward a potential transaction or partnership. Proceeds from Kaseba are earmarked as non-dilutive funding to drive Dumbwa forward. At the end of the current Phase 1 program, Midnight Sun expects to retain approximately C$15 million in treasury, providing a solid runway for continued drilling and potential maiden resource work later in 2026 or early 2027.

Why This Matters for Canadian Mining Investors

Midnight Sun Mining exemplifies the opportunity still available in the junior sector for those willing to back disciplined teams in top-tier jurisdictions. Zambia’s Copperbelt offers:

• World-class endowment and infrastructure.

• Stable (though evolving) mining regime.

• Proximity to major producers who actively seek new feed sources.

• Clear path from discovery to development in a copper-hungry world.

With copper prices supported by electrification, data centres, and renewable infrastructure, new discoveries in established belts like this one are particularly valuable. Dumbwa’s scale, continuity, and analogy to proven giants position it as a potential flagship asset for Midnight Sun and a project worth watching closely by investors in Canadian mining companies and copper exploration stocks.

Next Catalysts

• Steady assay releases from the ongoing 10,000+ m/month drill program.

• Expansion and infill drilling to extend fences and test copper clearing zones.

• Potential updates on the Kaseba oxide asset.

• Progress toward a maiden resource estimate once the initial 11 km is fully drilled.

O’Brien emphasized that the company is still in the early days of understanding Dumbwa. With six more kilometres to test on the southern target alone — and another ~9–10 km of untested anomaly to the north — the story has considerable room to grow.

Conclusion: A Significant Discovery in a Premier Jurisdiction

Midnight Sun Mining’s latest release marks a pivotal de-risking milestone. The scale of the Dumbwa system, its geological similarity to Lumwana, and the methodical approach taken by the team under Kevin Bonnel (a geologist with direct experience expanding Lumwana) give investors confidence that something genuinely substantial is emerging. In a world increasingly hungry for new copper supply, discoveries like Dumbwa in established, infrastructure-rich belts are rare and valuable. For Canadian investors seeking exposure to copper exploration with strong discovery potential and a clear path forward, Midnight Sun Mining warrants close attention.

Sources:

• Midnight Sun Mining press release and assay results (May 2026).

• Interview with Adrian O’Brien, VP Business Development, on Mining Stock Education with Bill Powers (May 2026).

• Company website and technical disclosures (midnightsunmining.com).

• Public data on Zambian Copperbelt geology and neighbouring operations (Barrick Lumwana, Ivanhoe Kamoa-Kakula, First Quantum Kansanshi).

This article reflects information publicly available as of May 16, 2026. Exploration results, drill programs, and corporate plans are subject to change — always verify the latest data directly from company filings and conduct independent research.