Midnight Sun Continues Rapid Strike Expansion at Dumbwa; Now 6.7 Kilometres of Near-Surface Copper Mineralization
Midnight Sun Continues Rapid Strike Expansion at
Dumbwa; Now 6.7 Kilometres of Near-Surface Copper
Mineralization
Highlights include: 21.64m @ 0.42% Cu, 13.67m @ 0.51% Cu, and 25m @
0.38% Cu
Vancouver, British Columbia, June 29 , 2026 – Midnight Sun Mining Corp. (TSXV:
MMA / OTCQX: MDNGF) (“Midnight Sun” or the “Company”) is pleased to report
additional results from 77 holes on its wholly owned Dumbwa copper deposit,
located in Solwezi, Zambia. Drilling has now surpassed 260 holes and 56,855 metres
("m"), confirming continuous near -surface sulphide copper mineralization over 6.7
kilometres ("km") of strike at Dumbwa. Five drill rigs continue to expand the deposit
northward along strike and laterally to the east and west of known mineralization.
Highlights of Drilling include:
• DBW-26-200 intercepted 0.42% Cu over 21.6m.
• DBW-26-165 intercepted 0.51% Cu over 13.7m.
• DBW-26-150 intercepted 0.38% Cu over 25.0m.
Midnight Sun’s President and CEO, Al Fabbro, states, "To date, we have demonstrated
that Dumbwa is , at a minimum , a 6,700 metre long and 600 m etre to 1,000 metre
wide, north-south, strain-controlled copper system. It is typically near, or at, surface,
and extends to greater than 200 metres depth. It features a high -grade, central
corridor ranging in width from 100 to 600 metres within a broader mineralized shell
which can exceed 1,000 metres in width.
Our initial, discovery drilling is broadly spaced with holes positioned 50 to 100 metres
apart on each of the east -west lines, with the lines spaced 100 to 200 m etres apart
north to south. As a result, on any individual line/section, it is expected that only 2 or
3 holes are positioned within the highest -grade corridor, while a higher percentage
of holes are positioned in the lower-grade shells. It is evident from our work to date;
the higher-grade core shows strong grades and continuity within individual segments
of the deposit.
As our drilling has progressed north of the disruption zone we just passed through,
we are again seeing good development of visually strong copper mineralization and
the northernmost holes we have reported today demonstrate the return of thick,
higher-grade mineralization within the central corridor of the deposit.”
The Company will host a technical webinar with Midnight Sun’s COO, Dr. Kevin Bonel,
to discuss the results announced in this news release on Tuesday, June 30th, 2026, at
10am PST. You can access the webinar via the link provided here: Webinar Link
Drilling Highlights Table:
Hole ID From (m) To (m) Interval (m) Cu (%)
DBW-26-200 0.36 22.00 21.64 0.42
DBW-26-180 0.00 21.00 21.00 0.21
DBW-26-177 3.50 29.00 25.50 0.18
DBW-26-176 3.00 27.30 24.30 0.27
and 35.00 53.70 18.70 0.27
DBW-26-165 19.33 33.00 13.67 0.51
DBW-26-159 144.00 172.00 28.00 0.25
DBW-26-150 97.00 122.00 25.00 0.38
and 151.8 174.00 22.20 0.25
and 195.00 209.00 14.00 0.38
DBW-26-142 197.07 215.00 17.93 0.23
and 218.75 231.00 12.25 0.26
• Assay results based on four-acid digest, ICP-OES finish. Intervals listed are based on drilling intervals
and therefore are considered relative rather than true widths.
• The full table of assays including locations is available on the Company’s website and can be accessed
through this link: Dumbwa Drill Hole Location and Assay Table.
Phase One Drilling Progress
Drilling has now intersected continuous near-surface sulphide copper mineralization
over 6.7km of strike at Dumbwa (see Figures 1, 2, 3 and 4 below). Assays have been
received for the first ~5.2km of the drilled trend, and five drill rigs are continuing
northward along strike and laterally to the east and west of known mineralization.
Recent drilling has focused on the continued expansion of the Dumbwa Deposit
northward, while also refining the lateral boundaries of mineralization, which has
resulted in an additional 1.4km of strike extension to the north. This drilling intersects
the same geology that characterizes Dumbwa, comprising flat - to gently east-dipping
biotite and muscovite- biotite schists hosting sulphide copper mineralization.
Importantly, the higher-grade core of the north-south-trending Dumbwa shear zone
has re-emerged beyond the northwest-southeast structural corridor, where weaker
schist development and associated grade attenuation had previously been
encountered. Mineralization remains open along the full extent of the copper-in-soil
anomaly, in select areas to the east and west, and at depth.
Approximately 12,500m of Phase One drilling remains to complete the planned
testing of the initial 11.5km strike extent, with the program expected to conclude in
Q3 2026.
The Strategy Behind Every Drill Hole
The objective has been to define the Dumbwa deposit quickly, methodically, and
completely. From the outset, the drill program has been designed to test the full
mineralized envelope, which includes the higher -grade core as well as the
surrounding lower-grade mineralization, in order to define the overall dimensions
and continuity of the system.
To achieve this, drill fences are spaced approximately every 100 to 200 m along the
20km strike of the target area, with drill holes positioned every 50 metres across each
east-west fence. Beginning at the southern property boundary, drilling has
progressively advanced northward, systematically building the deposit one fence at
a time.
This approach has now defined a mineralized system extending approximately
6.7km in strike length. The central higher -grade zone is typically between 200 and
600m wide with the total mineralized envelope commonly extending from 1.0 to
1.5km across (see Figures 3 and 4 below).
As a result, each drill fence typically contains only two to three holes within the
higher-grade core, while many holes test the surrounding lower- grade
mineralization. This is intentional. Demonstrating the full width and continuity of the
mineralized system requires drilling to its margins rather than focusing exclusively
on the higher-grade centre.
Concentration only on the higher -grade core would result in the deposit remaining
open to the east and west, leaving its true dimensions undefined. By systematically
drilling the entire mineralized corridor, we are establishing both the geometry of the
higher-grade core and the full extent of the broader mineralized system.
This context is critical when interpreting individual assay results. Viewed as a table of
drill intersections, many holes appear to return lower grades. Viewed in their
geological context, however, those same holes are defining the boundaries of a large,
continuous mineralized system while progressively delineating the significant higher-
grade core within it.
Figure 1: Dumbwa drilling to date, plotted on 11.5km Phase One copper-in-soil anomaly, target area.
Figure 2: Dumbwa drilling to date, magnified to show current 5.3km drilled strike extent, plotted on Phase One copper-in-
soil anomaly, target area.
Figure 3: Assay grade shells superimposed on the Dumba soil anomaly showing the correlation between high soil anomalies
and medium to high grade mineralised intercepts at Dumbwa. Drilling continues to follow the soil anomaly north.
Figure 4: 11.5 kilometre Phase One Target area - Assay grade shells superimposed on the Dumba soil anomaly showing the
correlation between high soil anomalies and medium to high grade mineralised intercepts at Dumbwa. Drilling continues
to follow the soil anomaly north.