Midnight Sun Extends Dumbwa Copper Deposit to Over 5.3 Kilometres; Remains Open Along Strike with Drilling Ongoing

The May 13 2026 release details assay results from the ongoing diamond‑drill campaign at the wholly owned Dumbwa copper sulphide target in Zambia. Continuous near‑surface mineralization has now been drilled over 5.3 km of strike, up from 3.6 km in the previous update (Jan 29 2026). Highlight intercepts include 1 m @ 5.94 % Cu, 8 m @ 1.71 % Cu, and broader zones such as 44 m @ 0.53 % Cu and 89 m @ 0.25 % Cu. The mineralized corridor ranges from 200 m to over 500 m wide, and drilling has now surpassed 200 holes for more than 42 000 m. The deposit remains open along strike and at depth, with a Phase One target of 11.2 km. The Company has resolved earlier laboratory issues at SGS Zambia and dispatched duplicate samples to Intertek in Australia. An additional 200 holes (≈40 000 m) are planned to extend mineralization further.

The extension of the mineralized strike to 5.3 km is a significant step forward, confirming that the Dumbwa system is large, consistent, and still expanding. This validation is directly in line with the Company’s stated ambition to delineate a bulk‑tonnage deposit analogous to Barrick’s nearby Lumwana mine. The new drill results are similar in tenor to prior intercepts – they show the system contains both broad, low‑grade zones and occasional high‑grade pods, which together support the conceptual +1 billion‑tonne exploration target.

However, the news is an incremental, not a transformative, update. It follows the well‑telegraphed pattern of expanding strike length, and the market already expected the deposit to remain open. No maiden resource, metallurgical data, or economic study has yet been produced for Dumbwa, so the economic viability remains unproven. The stock traded at $1.42 prior to the release, well below its 52‑week high of $1.90, indicating that prior positive drill results have not maintained momentum.

Nevertheless, the rapid pace of drilling and consistent copper values materially increase the probability that a substantial resource will be defined. This warrants a Material – Positive rating, as it adds genuine new data that significantly expands the known mineralized footprint, even if it is a predictable continuation.

Midnight Sun Mining is a Canadian‑based explorer focused entirely on the Zambian Copperbelt. Its flagship asset is the 100%‑owned Solwezi Project, which hosts two principal targets:
- Dumbwa: A basement‑hosted sulphide copper system analogue to Barrick’s Lumwana mine. The target is a near‑surface, bulk‑tonnage opportunity with a 20 km soil anomaly; the current drilling has defined a continuous mineralized zone over 5.3 km.
- Kazhiba Main: A near‑surface oxide copper deposit that now has a maiden indicated resource of 2.33 Mt @ 1.41 % Cu (72.3 M lbs Cu). The Company intends to sell or partner this deposit to generate non‑dilutive cash.

The Company also holds the Mitu and newly acquired Luswishi Dome properties, which are earlier‑stage targets. Midnight Sun’s strategy is to drill aggressively at Dumbwa with the aim of outlining a +1 billion‑tonne resource, while using the oxide assets to self‑fund. Drilling costs are low (≈$160/m all‑in), and five rigs are currently turning, with a sixth in early 2026.