SCMI.V · 2025-12-19 12:00:00

High-Grade Drill Intercepts at Minto North West Zone and Ridgetop Zone Confirm the Potential of the Minto Copper-Gold-Silver System

Drill Results

High-Grade Drill Intercepts at Minto North West Zone and Ridgetop Zone Confirm

the Potential of the Minto Copper-Gold-Silver System

Highlights

• Results from the ongoing drilling program include the following high-grade intercepts:

o Minto North west zone: 4.96% Cu, 0.85 g/t Au, 18.67 g/t Ag over 9.9 m from 225.1 m, within a

broader zone of 2.34% Cu, 0.43 g/t Au and 8.69 g/t Ag over 24.0 m in drill hole 25SCM009, a 150 m

southern step out at the Minto North west zone

o Ridgetop zone: 1.46% Cu, 0.47 g/t Au, 4.04 g/t Ag over 14.7 m from 90.3 m within a zone of 1.02%

Cu, 0.37 g/t Au, 3.17 g/t Ag over 27.7 m in drill hole 25SCM006 and 2.20% Cu, 0.80 g/t Au, 4.52 g/t

Ag over 7.0 m from 108.0 within a zone of 1.36 % Cu, 0.5% g/t Au, 2.92 g/t Ag over 23 m in drill

hole 25SCM004 both testing an under drilled area within the Ridgetop zone

• As of December 19, 2025, 32,026 m of drilling, or 64% of the planned 50,000 m program, in 121 drill

holes has been completed including a total of 8,979 m at the Minto North west zone

Trade-Off Study and Metallurgical Testwork Program

• Hatch Ltd. and SRK Consulting (Canada) Inc. continue to advance design and engineering work in mine

planning and design, metallurgy, mineral processing, waste rock and tailings management, all working

directly with the Company and consultants representing the Selkirk First Nation

• Preliminary results from a metallurgical testwork program, with the aim of improving copper, gold, and

silver recoveries on the Ridgetop deposit and to determine the possibility to improve recoveries of

precious metals using gravity recovery, are positive

Annual General and Special Meeting

• Selkirk Copper Mines Inc. held its Annual General and Special Meeting (the “Meeting”) on December

17th, 2025 in Whitehorse, YK where shareholders approved all the matters of business before the

company

December 22, 2025 - Vancouver, BC and Pelly Crossing, YT – Selkirk Copper Mines Inc. (TSX-V: SCMI |

FRA:IO20) (“Selkirk Copper” or the “Company”) is pleased to provide a program update and announce new

assay results from the on going 50,000 m drill program. The drill program has paused for the holiday break with

the safe completion of 32,026 m across 121 drill holes which marks a 64% completion of the planned program.

New results have been received from nine drill holes, three from the Minto North west zone, and six from the

southern Ridgetop zone (Figure 1). Drilling continues to test the size and continuity of the high-grade Minto

North west zone and these results confirm the expansion of the mineralized zone by 150 m south of the

previously modelled zone . Drilling at the Ridgetop zone is testing a high-grade corridor within the open pit

resource. Drill holes 25SCM004 and 25SCM006 successfully intercepted similar grade and width to the

expected high-grade corridor.

M. Colin Joudrie, President & CEO, commented: “I am extremely pleased with results at the Minto North west

zone which confirms our view that this zone has significant growth potential, with high copper and gold grades

intersected over significant widths . In addition, the Trade-Off Study, including metallurgical testing , is

advancing on schedule and is benefitting from input from Selkirk First Nation’s consultants. I am particularly

encouraged by initial results from the Ridgetop geometallurgical testwork which is showing potential for

significant improvements in copper recovery from partially oxidized material compared to historic work. Lastly,

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I am very pleased with support from shareholders that resulted in Selkirk Copper completing its planned reverse-

take-over and business amalgamation in October 2025, and the initiation of trading on the TSX Venture

Exchange of Selkirk Copper Mines Inc. (TSX-V:SCMI) in early November 2025.”

2025 Drill Program Update

Drilling of 32,026 m of the planned 50,000 m program has been completed safely meeting our environmental

and sustainability standards (Figure 1). Drilling is expected to resume mid-January 2026, with results continuing

to be released as assays are received and validated. Table 1 summarizes meters and holes drilled by zone.

The remaining program is focused on the Ridgetop, Copper Keel, Minto East, and Minto North zones (Figure

1), exploration following up on historical high-grade results between the Minto East and Minto North zones

referred to as the Inferno zone (Figure 2), testing greenfield targets north of the current infrastructure, and testing

newly interpreted regional structures coincident with geophysical anomalies. To date, 9,382 samples have been

prepared and shipped for analysis, with results to be released following completion of all QAQC reviews.

Figure 1: Plan view of the Minto Mine showing surface projections of mineralization zones (Ridgetop, Copper Keel, 118, Minto East

and Minto North), relative to 2025 drill collars (yellow circles).

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Table 1: Drilling by Zone

Zone Holes

completed Meters drilled

Minto North 28 8,979

Ridgetop 58 11,911

Minto East 15 5,406

Copper Keel 7 1,990

118 13 3,740

Total 121 32,026

Figure 2: Global cross-section view looking west showing the five primary zones of mineralization: Ridgetop (yellow), 118 (blue),

Copper Keel (green), Minto East (purple), and Minto North (red). The section illustrates gently north-dipping mineralized zones over

approximately 3 km of strike length and down to approximately 550 m depth, which has hosted the majority of exploration activity within

a larger 7 km long property.

Drill Results

Minto North

Drilling at the Minto North west zone continues to demonstrate a high-grade, laterally continuous copper-gold-

silver system with strong geological consistency along strike. Drill hole 25SCM009, the most southerly step-

out completed to date, successfully extended the mineralized footprint by approximately 150 m to the south.

This zone remains open in the southern, eastern and northern directions (Figure 3).

Hole 25SCM009 intersected a broad >24 m mineralized interval beginning at 210.97 m, hosted within strongly

deformed assimilation zone (ASMZ) and migmatitic (MIGM) lithologies characterized by increasing foliation

intensity, magnetite alteration, and elevated sulphide content. Within this interval, a high-grade massive

sulphide zone dominated by bornite and chalcopyrite was intersected from 233.07 m to 234.00 m, returning

34.1% Cu, 2.03 g/t Au and 170 g/t Ag. This style of mineralization, including massive to semi-massive sulphide

textures and a high bornite -to-chalcopyrite ratio, is consistent with high-grade intervals previously reported in

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drill holes 25SCM001 and 25SCM002.

Drill holes 25SCM007 and 25SCM014 provide additional confirmation that the overall mineralized and altered

system remains a thick and laterally extensive package. Hole 25SCM007 intersected a broad zone of altered

ASMZ and MIGM lithologies with elevated copper values from approximately 210 m to 251 m, representing a

>40 m thick package of deformed and altered host rock. In this drill hole, a significant intercept of 13.92 m from

237.00 m returned 0.51% Cu, 0.13 g/t Au and 2.17 g/t Ag, consistent with mineralization observed in

25SCM005 (see news release Dec 1, 2025). These results illustrate a gradual easterly transition from the high-

grade, bornite-rich core characteristic of the Minto North west zone into a broad chalcopyrite-dominant halo.

Drilling to date has successfully identified chalcopyrite and bornite extending over 208 m in strike length, nearly

doubling the 105-metre extent defined in the 2025 mineral resource estimate (MRE) model (Figure 3). For more

information on the 2025 MRE see Table 4.

Figure 3: Plan View of the Minto North west zone. Sulphide mineralization observed in drilling extends the N-S strike direction to 208

meters (dashed outline) compared to the previously modelled 105 meter strike length (red shaded shape).

Ridgetop

Drill holes 25SCM004, 006, 008, 010, 011 and 012 drilled at the Ridgetop zone targeted an under-drilled

portion of this open pit resource situated between the well-defined shallow western pit (to <150 m depth) and

a higher-grade, deeper zone to the east (Figure 4). This corridor has historically returned assays exceeding 2%

copper and represents a key area for improving geological confidence within the existing resource model.

Results from drill holes 25SCM004 and 006 successfully confirm ed the width and grade of this deep

mineralized zone, demonstrating continuity of copper -rich mineralization within ASMZ and migmatitic host

rocks. However, drilling also indicates that the Ridgetop zone is more structurally complex than previously

interpreted, with evidence for late -stage faulting and localized offsets disrupting portions of the mineralized

horizon.

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These recent drill results are informing structural reinterpretation at Ridgetop which will be integrated into

updated geological and resource models to better constrain fault geometry and mineralization offsets. The

systematic collection of oriented drill core and the development of a robust structural model are critical for

improved geological modelling and better defined mine plans.

Figure 4: A) Simplified plan view of the 2025 MRE Ridgetop open pit with 2025 drilling highlighting two main areas of focus

including a high-grade corridor at depth and the expansion of drilling to the south. B) shows an inclined view of 2025 MRE open pit

and the 2025 completed drill traces. C) is a 150 m thick cross-section looking NW highlighting results received to date.

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The location, azimuth, dip and depth of hole of this new drilling is summarized in Table 2 and significant

intervals is summarized in Table 3.

Table 2: Collar Locations and Header Information

Hole ID Easting Northing Azi Dip EOH Zones

25SCM004 385177 6943771 105 -63 255 Ridgetop

25SCM006 385177 6943771 131 -58 303 Ridgetop

25SCM007 384004 6945916 60 -80 405 Minto North

25SCM008

385177 6943771 135 -74 264 Ridgetop

25SCM009

384002 6945913 135 -70 450 Minto North

25SCM010

385177 6943771 180 -58 234 Ridgetop

25SCM011

385177 6943771 210 -70 234 Ridgetop

25SCM012

385175 6943772 190 -86 369 Ridgetop

25SCM014

384001 6945913 180 -70 399 Minto North

Table 3: Significant Interval Table

Hole ID From To Length

(m)

Cu % Au

g/t

CuEq % Lith Zone

25SCM004 108.0 131.0 23.0 1.36 0.50 2.92 1.75% ASMZ RT

Incl. 115.0 122.0 7.0 2.20 0.80 4.52 2.84% ASMZ

144.23 145.0 0.8 2.45 0.02 2.19 2.49% ASMZ

237.14 244.7 7.6 0.44 0.09 1.67 0.53% ASMZ

25SCM006 90.29 118.0 27.7 1.02 0.37 3.17 1.32% ASMZ RT

Incl. 90.29 105.0 14.7 1.46 0.47 4.04 1.85% ASMZ

220.0 224.11 4.1 1.00 0.22 3.28 1.19% ASMZ

235.7 237.54 1.84 4.38 0.71 34.78 5.21% ASMZ

25SCM007 237.0 250.92 13.9 0.51 0.13 2.17 0.63% ASMZ MN

25SCM008 111.0 116.0 5.0 0.59 0.24 2.20 0.79%

ASMZ RT

25SCM009 210.97 235.0 24.0 2.34 0.43 8.69 2.74% ASMZ MN

Incl. 225.09 235.0 9.9 4.96 0.85 18.67 2.37%

ASMZ

25SCM010 85.0 88.5 3.5 0.47 0.21 1.88 0.29% MIGT RT

25SCM011 123.0 131.0 8.0 0.35 0.05 0.66 0.39% MIGT RT

141.0 146.0 5.0 0.33 0.04 0.82 0.39% ASMZ

162.0 165.64 3.6 0.39 0.06 1.23 0.37% ASMZ

25SCM012 92.5 103.5 11.0 0.33 0.21 0.82 0.45% ASMZ RT

123.0 125.0 2.0 1.05 0.03 0.86 0.50% ASMZ

134.0 135.78 1.8 1.23 0.01 0.56 1.08% ASMZ

150.4 158.0 7.6 0.47 0.07 1.43 1.24% ASMZ

25SCM014 203.65 220.63 17.0 0.75 0.47 3.88 1.13% ASMZ MN

Incl. 211.68 217.6 5.9 1.33 1.07 7.62 2.19% ASMZ

At the Minto North zone, the flat laying to shallowly dipping nature of the mineralized zones suggest that true widths are typically >90% of the

reported drill intersection length. At Ridgetop, true widths are approximate 85-90% of reported drill intersection lengths.

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ASMZ = Assimilation Zone; MIGT = Migmatite

RT = Ridgetop; MN = Minto North

NSI = No Significant Intervals

CuEq Calculation:

CuEq = ((Cu% × CuP × RCu × 2204.62)+(Au g/t ÷ 31.1035 × AuP × RAu) + (Ag g/t ÷ 31.1035 × AgP × RAg ))/(CuP × RCu × 2204.62)

Where:

CuP/AuP/AgP = US$ commodity prices of $4.25/lb Cu, $2500/oz Au, $29/oz Ag; R Cu = Cu Recovery = 98%; R Au = Au Recovery = 85%; R Ag= Ag

Recovery = 85%

Recoveries as estimated from historical mineral processing results.

Trade-Off Study and Metallurgical Testing Update

Engineering work on the Trade-Off study continues to progress well, with Hatch Ltd. and SRK Consulting

(Canada) Inc. advancing design and engineering work on all fronts including mine design, infrastructure,

processing, mine waste, tailings, water management and treatment, and economics. Importantly, this work is

being carried out in a collaborative manner with direct input from the Selkirk First Nation and their consultants

as well as Selkirk Copper’s senior team.

After a comprehensive review of previous operating data and historical metallurgical test work, the team

identified opportunities to increase metallurgical recoveries in Ridgetop zone mineralization as well as

opportunities to reduce power consumption in crushing, grinding, and milling of Minto-style mineralized

material. Three areas with potential upside being investigated are: i) improved energy efficiency in the mill by

increasing the primary grinding size; ii) additional processing options for material that has higher distribution

of copper present as copper oxide; and iii) further investigating gravity concentrate to increase gold recovery.

In November 2025, Selkirk Copper began Phase 1 of a metallurgical test program, with the primary aim of

better understanding Minto -style mineralization through a n integrated geometallurgical program aimed at

improving the mine’s production capabilities and metallurgical recoveries of partially oxidized mineralization.

The test work is being conducted at Blue Coast Research Ltd., located in Parksville, BC with input from Selkirk

Copper and its consultants, including Fuse Advisors Inc., and Hatch Ltd. Initial test work has started based on

existing core samples with plans for additional metallurgical test work based on materials from new drilling.

Eary indications from the test work are positive in all respects, specifically: i) initial results suggest coarsening

the primary grind size maintains high copper recover y and would have the potential to reduce power

consumption in milling; and ii) initial results from flotation tests are showing better copper recovery from

partially oxidized mineralized material than previously modeled, which has the potential to convert material

previously modeled as waste into potentially minable resources. Tests to assess gravity assisted recovery of

gold and silver are underway.

In 2026 the Company will further advance the geometallurgical test work program using core acquired from

the current drill program with the long -term goal of linking the geologic understanding of the mineralized

zones at Minto directly to their metallurgical behavior ideally resulting in improved recovery of copper, gold

and silver at lower cost.

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QAQC Procedures and Data Validation

The Company is drilling NQ sized core. Following data collection, core is cut along the long axis, with half of

the core going to the lab for chemical analysis and the remaining half kept in sequence as record. The half core

samples are packaged with the corresponding sample tag id and sealed. All sampling is conducted by Selkirk

Copper Mines Inc. and subject to Company standard internal quality control and quality assurance (QAQC)

programs which include the insertion of certified reference material, coarse blank materials, and field duplicate

analysis, on top of the standard laboratory QAQC procedures to monitor contamination during preparation and

analytical accuracy and precision. QAQC insertion rates approximate 15% of all samples at set intervals. For

the 2025 program all samples were sent to ALS Laboratory’s prep laboratory in Whitehorse, YK, then shipped

to ALS Vancouver for gold fire assay and four -acid multi-element analysis. All s amples are prepared by

crushing rock to 70% passing 2mm screen, then splitting a 250g sub-sample using a riffle splitter before being

pulverized 85% passing 75 microns. Gold is analyzed by 30 g Fire Assay (Au-AA23) with atomic absorption

(AAS) analysis followed by gravimetric finish for overlimit results . Copper is analyzed by four-acid digest

(ME-ICP61) with inductivity couple d plasma – atomic emission spectro scopy (ICP-AES) finish. If Cu

overlimit results are triggered a second four-acid digest for high grade copper (Cu-OG62) is conducted. For

any samples where oxide copper minerals are identified, a sulphuric acid leach (Cu-AA05) analysis with AAS

finish is preformed. ALS Vancouver holds an ISO/IEC 17025 standard accreditation.

QAQC results are reviewed open receipt of results. Overall QAQC results show strong analytical performance

across Cu, Au, and Ag datasets. All control standards are within acceptable tolerance, with no significant

outliers or systematic bias observed.

Primary intervals are reported as drill core length, with true widths estimated to be approximately 90% of core

lengths, based on the sub-horizontal to shallow dipping nature of the modelled mineralized zones.

Mineral Resource Details

The following table (Table 4) summarizes the current Minto Mineral Resource:

Table 4: Global Mineral Resource Estimate for the Minto Project (Effective Date: April 7, 2025)

Type Cut Class ROM In Situ Grade Metal

(CDN$) Tonnage

(000)

NSR

(CDN$)

(%)

(gpt)

Ratio

ASCu

(%)

(Mlbs)

(Koz)

OP $30

Indicated 6,085 $89.11 0.897 0.274 2.9 0.15 0.163 120.3 53.7 560.4

Inferred 9,496 $73.71 0.702 0.162 2.4 0.07 0.057 146.9 49.3 738.4

UG $80

Indicated 6,504 $183.90 1.489 0.636 5.6 0.06 0.090 213.5 132.9 1,167.6

Inferred 14,162 $156.85 1.281 0.539 4.9 0.06 0.075 399.9 245.4 2,229.6

Total

Varies

Above

Indicated 12,588 $138.08 1.203 0.461 4.3 0.10 0.125 333.8 186.6 1,728.0

Inferred 23,658 $123.48 1.048 0.387 3.9 0.07 0.068 546.8 294.7 2,968.1

Notes

1. The MRE has been completed by Sue Bird of Moose Mountain Technical Services (MMTS).

2. Resources are reported using the 2014 CIM Definition Standards and were estimated using the 2019 CIM Best Practices Guidelines.

3. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

4. Metal prices of US$2000/oz Au, US$23/oz Ag, US$4.00lb Cu.

5. For the NSR calculations: a currency exchange rate of 0.72 US$ per $CA; 95% payable Cu, 88% payable Au and 70% payable Ag; offsite costs

(refining, transport and insurance) of US$256.18/dmt; royalties of 1.5% NSR.

6. Recoveries are as follows:

a. CuRec = 95.5%+1.07*Cu%-113*ASCu/TCu, with a maximum of 98%

b. AuRec = 20.99*Augpt + 62.01, with a maximum of 95%

c. AgRec = 69.4+1.9*Aggpt, with a maximum of 85%

7. These inputs result in the following NSR and CuEq equations:

NSR = CA$4.73*CuRec*Cu%*22.0462 + (CA$2400.60*AuRec*Augpt + CA$21.45*AgRec*Aggpt)/31.10348

CuEq = NSR/(Cu*CuRec*22.0462)

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