NCX.V · 2026-08-06 12:00:00

Northisle Announces Significant Increase to North Island Resource Estimate Contained Metal in Indicated Resources Increased to 10.1 billion lbs Cu Eq. or 16.2 million oz Au Eq.

Resource Estimates

Northisle Copper and Gold Inc. | 520 – 1050 West Pender St. | Vancouver, BC | V6E 3S7

www.northisle.ca | [email protected]

August 6, 2026

TSXV: NCX

OTCQX: NTCPF

Northisle Announces Significant Increase to North Island Resource Estimate

Contained Metal in Indicated Resources Increased to 10.1 billion lbs Cu Eq. or 16.2 million oz Au Eq.

All dollar ﬁgures are C$ unless otherwise stated

Highlights:

• Increased Indicated Resources by 330 million tonnes (+36%), adding 685 million lbs Cu (+22%) and

1.8 million oz Au (+26%) in contained metal

• 60% increase in contained Cu Eq. metal in Indicated Resources

• Exceeded resource objectives at West Goodspeed

o Addition of 113.1 million tonnes of Indicated Resources containing 873 million lbs Cu Eq. or 1.2

million oz Au Eq.

• Successful resource conversion at Northwest Expo and expansion of the resource along strike, which

remains open to the northwest

o Contained Au in Indicated Resources increased 81% to 1.7 million oz

o Contained Cu in Indicated Resources increased 84% to 198 million lbs

• 30% increase in contained Cu Eq. metal in Indicated Resources at Red Dog with connection between

Red Dog and West Goodspeed to be investigated with additional drilling in 2026

• Additional critical minerals exposure with contained molybdenum in Indicated Resources increasing

by 46% and contained rhenium in Indicated Resources increasing by 43%

See below for further details

Vancouver, B.C. – Northisle Copper and Gold Inc. (TSX-V: NCX, OTCQX: NTCPF) (“Northisle” or the

“Company”) is pleased to announce the release of an integrated mineral resource estimate for its 100%

owned North Island Project (the “2026 Resource Esti mate”), which integrates the Northwest Expo, Red

Dog, West Goodspeed, and Hushamu deposits. The 2026 Resource Estimate will be used for the

development of a pre-feasibility study (“PFS”) on the North Island Project, which remains on target for

completion in Q1 2027.

Alex Davidson, Chairman, noted “This integrated resource update represents another important milestone

for Northisle and is a critical step towards the completion of the North Island Project PFS. With 10.1 billion

pounds of copper equivalent or 16.2 million ounces of gold equivalent contained in Indicated Resources,

the 2026 Resource Estimate is ﬁnally beginning to tell the story of th e district-scale potential of the North

Island Project. ”

Sam Lee, President & CEO, stated “Over the past 18 months, we have either achieved or exceeded each of

the goals we set in respect to resource growth an d conversion. At West Good speed, we added over 113

million tonnes of Indicated Resources with 873 million lbs Cu Eq., or 1.2 million oz Au Eq. in contained

metal. At Northwest Expo, we successfully converted Inferred material, increasing Indicated tonnage by

Northisle Copper and Gold Inc. | 520 – 1050 West Pender St. | Vancouver, BC | V6E 3S7

www.northisle.ca | [email protected]

133%, and expanded the resource along strike. Signi ﬁcantly, at Red Dog, we increased contained copper

equivalent metal in Indicated Resources by 30% and plan to investigate the connection between Red Dog

and West Goodspeed with additional drilling in 2026. We additionally increased our exposure to critical

minerals beyond copper, adding 68 million lbs Mo and 362,000 lbs Re in Indicated Resources. These

results, in addition to improved commodity prices, have driven meaningful resource growth and provide a

solid foundation for the North Island Project PFS, which remains on target for completion in Q1 2027. ”

The 2026 Resource Estimate contains an Indicated Resource of 1.2 billion tonnes grading 0.14% Cu, 0.22

g/t Au, 79.5 ppm Mo and 0.44 ppm Re for total containe d metal of 10.1 billion lb s copper equivalent (“Cu

Eq. ”) or 16.2 million oz gold equivalent (“Au Eq. ”) (r ecovery adjusted), plus an I n f e r r e d R e s o u r c e o f 2 6 0

million tonnes grading 0.12% Cu, 0.15 g/t Au, 62.0 ppm Mo, and 0.37 ppm Re for total contained metal of

1.5 billion lbs Cu Eq. or 2.6 million oz Au Eq. (recovery adjusted), at an $11.00/tonne NSR cut-oƯ.

Additionally, the 2026 Resource Estimate describe s a shallow higher-grade portion of the Hushamu

deposit (the “Hushamu Shallow Higher-Grade Core”) , which is expected to be included in the ﬁrst

pushback to be extracted from the Hushamu deposit. In aggregate, the deposits comprising the Northwest

Corridor, including Northwest Expo, Red Dog, and West Goodspeed, plus the Hushamu Shallow Higher-

Grade Core, contain an Indicated Resource of 405 mill ion tonnes grading 0.50% Cu Eq. or 0.46 g/t Au Eq.

for total Indicated contained metal of 4.5 billion lbs Cu Eq. or 6.0 million oz Au Eq.

The 2026 Resource Estimate has an eƯective date of July 31, 2026, and is summarized in Table 1 below by

deposit. The 2026 Resource Estimate was prepared by Sue Bird, P .Eng. of Moose Mountain Technical

Services (“MMTS”) who is independent of Northisle. Me tallurgical test work which is referenced in the

Design Basis (as deﬁned below) was completed under the supervision of Peter Mehrfert, P .Eng. of Ausenco

Engineering Canada ULC (“Ausenco”). A technical report (the “Technical Report”) prepared in accordance

with National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”) will be ﬁled

on the Company’s website and SEDAR+ within 45 days of the date of this press release.

Key assumptions reﬂected in the 2026 Resource Estimate are detailed below for each deposit and will be

further described in the Technical Report. With the release of the 2026 Resource Estimate, the Company’s

previous technical reports, including the 2025 Nort h Island Project Preliminary Economic Assessment

dated February 12, 2025, are no longer current and should not be relied upon.

The $11.00/tonne NSR cut-o Ư was selected as having reasonable prospects of eventual economic

extraction as this value covers preliminary estimated Phase 2 processing and G&A costs as detailed in the

Design Basis below. The economic assumptions presented may change during the completion of the

ongoing North Island Project PFS.

Northisle Copper and Gold Inc. | 520 – 1050 West Pender St. | Vancouver, BC | V6E 3S7

www.northisle.ca | [email protected]

Table 1: 2026 Integrated North Island Project Resource Estimate ($11.00 NSR cut-oƯ)

Grade Contained Metal

Tonnes Cu Au Mo Re Cu Eq. Au Eq. Cu Au Mo Re Cu Eq. Au Eq. NSR

(000 T) (%) (g/t) (ppm) (ppm) (%) (g/t) (mm lbs) (000s oz) (mm lbs) (000 lbs) (mm lbs) (000s oz) ($/t)

Indicated

Northwest

Expo 105,156 0.09 0.50 89.2 0.35 0.79 0.58 198 1,690 21 81 1,823 1,959 77.46

Red Dog 90,463 0.19 0.22 32.6 0.20 0.42 0.41 379 627 7 40 845 1,181 48.51

West

Goodspeed 113,070 0.16 0.16 61.2 0.40 0.35 0.32 397 573 15 99 873 1,166 35.14

Hushamu 927,672 0.14 0.20 85.2 0.48 0.32 0.40 2,818 5,825 174 988 6,604 11,862 31.51

Total

Indicated 1,236,361 0.14 0.22 79.5 0.44 0.37 0.41 3,793 8,715 217 1,209 10,145 16,168 36.99

Inferred

Northwest

Expo 7,395 0.04 0.26 69.7 0.28 0.44 0.30 7 62 1 5 72 72 40.45

Red Dog 3,421 0.21 0.14 31.6 0.22 0.37 0.36 16 16 0 2 28 39 42.43

West

Goodspeed 38,991 0.13 0.13 52.3 0.38 0.28 0.26 111 157 4 32 243 323 28.24

Hushamu 210,433 0.12 0.14 64.0 0.38 0.25 0.32 545 979 30 176 1,174 2,142 24.52

Total

Inferred 260,240 0.12 0.15 62.0 0.37 0.26 0.31 678 1,214 36 214 1,517 2,576 25.77

Notes to the Resource Table:

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

2. The Mineral Resources have been conﬁned by an open pit with "reasonable prospects of eventual economic extraction" using the 125% revenue

factor case and the following assumptions:

• Metal prices of US$3,587/oz Au, US$4.82/lb Cu, US$20/lb Mo US$2,000/lb Re

• Forex of 1.32 $CDN:$US

• Payable metal of 97.5% payable Au, Payable of 96.5% for Cu, 99% payable Mo, and 50% payable Re

• Reﬁning Costs of US$4.86/oz for Au, US$0.053/lb for Cu, US$0.95/lb for Mo, and US$0.60/lb for Re

• Smelting costs for Cu of US$53.20/dmt for Cu and US$98.80 for Mo

• Transportation and insurance costs of CDN$120/wmt proportionally distributed between Au, Cu and Mo

• Royalty of 1% NSR for Red Dog and West Goodspeed deposits

• Pit slopes are variable based on geotechnical zones and range from 31 degrees to 49 degrees, depending on sector

• Mining cost of US$3.00/t for waste and mineralized material

• Processing costs of CDN$10.30/t, general and administrative costs of CDN$0.70/t

3. Metallurgical recoveries for Au are: 91% for NW Expo, 84.5% for Red Dog, 78.2% for WGS and 59.2% for Hushamu in the CMG and 54.3%

outside the CMG.

4. Metallurgical recoveries for Cu are variable at NW Expo and WGS as in Table 9. At NW Expo averaging 73.8% and averaging 79.2% at WGS. Cu

recovery is 89.7% at Red Dog and 77.8% at Hushamu within the CMG and 75.4% outside the CMG.

5. Metallurgical recoveries for Mo are 45.0% at NWExpo and Red Dog and variable at WGS with an average of 43.0%, and 49.2% at Hushamu within

the CMG and 44.6% outside the CMG.

6. Metallurgical recoveries for Re are 36% at NWExpo and Red Dog and variable at WGS with an average of 34.5% at WGS, and 39.3% at Hushamu

within the CMG and 35.7% outside the CMG.

7. The NSR equations are:

• NW Expo within the CMG: NSR (CDN$/t)=(Au*91%*CDN$146.04g/t)+(Cu*CuRec%*CDN$5.98+Mo%*45%*CDN$24.63 +

Re%*36%*CDN$1306)*2204.62

• Red Dog: NSR (CDN$/t)=(Au*84.5%*CDN$141.34g/t) + (Cu*89.7%*CDN$5.79+Mo%*45%*CDN$24.39 +

Re%*36%*CDN$1293)*2204.62

• Hushamu within the CMG: NSR (CDN$/t)=((Au*59.2%*CDN$141.29g/t) + (Cu*77.8%*CDN$5.78 + Mo%*24.63*49.2% +

Re%*CDN$1306*39.3%)*2204.62

• Hushamu outside the CMG: NSR (CDN$/t)=((Au*54.3%*CDN$142.20g/t) + (Cu*75.4%*CDN$5.82 + Mo%*24.63*44.6% +

Re%*CDN$1306*35.7%)*2204.62

Northisle Copper and Gold Inc. | 520 – 1050 West Pender St. | Vancouver, BC | V6E 3S7

www.northisle.ca | [email protected]

• WGS: NSR (CDN$/t)=(Au*78.2%*CDN$140.08g/t) + (Cu*CuRec%*CDN$5.74+Mo%*MoRec%*CDN$24.39 +

Re%*ReRec%*CDN$1293)*2204.62

8. The Equivalent equations are: Cu Eq. = NSR/(Cu_NSP*Cu_Rec%*22.0462), Au Eq. = NSR/(Au_NSP*AuRec%)

9. The speciﬁc gravity for each deposit and domain ranges from 2.62-2.86 depending on alteration and is assumed to be 1.5 in overburden.

10. Numbers may not add due to rounding.

Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no

certainty that all or any part of the mineral resources will be converted into mineral reserves. Inferred

mineral resources are subject to uncertainty as to their existence and as to their economic and legal

feasibility. The level of geological uncertainty associat ed with an inferred miner al resource is too high to

apply relevant technical and economic factors likely to inﬂuence the prospects of economic extraction in

a manner useful for evaluation of economic viability.

These mineral resource estimates include Inferred mineral resources that are considered too speculative

geologically to have economic considerations applied to them that would enable them to be categorized

as mineral reserves. Mineral Resources that are not Mineral Reserves do not have demonstrated economic

viability.

The Qualiﬁed Person(s) are of the opinion that issues relating to all relevant technical and economic factors

likely to inﬂuence the prospects of eventual economic extraction can be resolved with further work. These

factors may include environmental perm itting, infrastructure, sociopolitical, marketing, or other relevant

factors.

Figure 1 shows the location of the deposits within the North Island Project in the context of regional

infrastructure.

Northisle Copper and Gold Inc. | 520 – 1050 West Pender St. | Vancouver, BC | V6E 3S7

www.northisle.ca | [email protected]

Figure 1: North Island Project Showing Location of Deposits and Prospects

Coordinates are reported in UTM Zone 9 North (NAD83 CRS, VD CVG28BC) with units in metres.

Exploration and Development Milestones

The Company continues to advance the North Island Project, with multiple near-term development and

exploration catalysts including:

• COMPLETED – C$115 million ﬁnancing to advance the North Island Project

• COMPLETED – Drilling results at Northwest Expo, extending strike and deﬁning higher-grade zones

• COMPLETED – Commence extension drilling in Northwest Corridor

• COMPLETED – Initiate early engagement on mine waste storage area (ahead of schedule)

• COMPLETED – Drilling results at Red Dog, conﬁrming additional higher-grade mineralization

extending below the previous resource envelope

• COMPLETED – Integrated resource update for the North Island Project

• Q3 2026 – Initiate drilling at regional exploration targets

• H2 2026 – Initial Project Description ﬁled

• H2 2026 – Commence BC Hydro System Impact Study

• H2 2026 – Results from ongoing drilling (Northwest Corridor and regional exploration)

• Q1 2027 – North Island Project PFS results announced

• Ongoing – Metallurgical test work (results to be included in North Island Project PFS)

• Ongoing – Continued positive engagement with indigenous rightsholders and local stakeholders

Northisle Copper and Gold Inc. | 520 – 1050 West Pender St. | Vancouver, BC | V6E 3S7

www.northisle.ca | [email protected]

Details of Northwest Expo Resource Estimate

The Northwest Expo Resource Estimate includes a to tal of 61 diamond drill holes totalling 24,966 metres

drilled by Northisle and previous operators through the end of 2025, of which 31 holes totalling 10,629

metres were completed under the direction of Northisle between 2024 and 2025.

Table 2 below summarizes the Northwest Expo Resource Estimate and shows the sensitivity of the

estimate to cut-oƯ assumptions.

Table 2: 2026 Northwest Expo Resource Estimate

In Situ Grade Contained Metal

NSR Cutoff Resource Tonnes NSR Cu Au Mo Re Cu Eq. Au Eq. Cu Au Mo Re Cu Eq. Au Eq. Strip

($/T) Class (000 T) ($/t) (%) (g/t) (ppm) (ppm) (%) (g/t) (mm lbs) (000s oz) (mm lbs) (000 lbs) (mm lbs) (000s oz) Ratio

$10.00

Indicated 106,083 76.87 0.08 0.50 89.03 0.35 0.78 0.58 199 1,692 21 82 1,826 1,962

3.65

Inferred 7,525 39.93 0.04 0.26 69.07 0.28 0.44 0.30 7 62 1 5 73 72

$11.00

Indicated 105,156 77.46 0.09 0.50 89.20 0.35 0.79 0.58 198 1,690 21 81 1,823 1,959

3.69

Inferred 7,395 40.45 0.04 0.26 69.65 0.28 0.44 0.30 7 62 1 5 72 72

$15.00

Indicated 99,721 80.96 0.09 0.52 88.82 0.35 0.82 0.61 197 1,676 20 76 1,801 1,942

3.96

Inferred 6,818 42.78 0.04 0.28 71.17 0.29 0.47 0.32 6 61 1 4 70 70

$20.00

Indicated 90,586 87.36 0.10 0.57 84.88 0.33 0.88 0.65 196 1,647 17 66 1,754 1,904

4.48

Inferred 5,738 47.45 0.05 0.31 70.80 0.28 0.51 0.36 6 57 1 4 65 65

Refer to Table 1 for Notes to the Resource Table.

Figure 2 below shows the resource pit shell and modelled block grades for the Northwest Expo deposit

showing the NSR blocks above the $11.00/tonne cut-oƯ.

Northisle Copper and Gold Inc. | 520 – 1050 West Pender St. | Vancouver, BC | V6E 3S7

www.northisle.ca | [email protected]

Figure 2: Northwest Expo Resource Shell and Block Model Showing NSR/tonne

Coordinates are reported in UTM Zone 9 North (NAD83 CRS, VD CVG28BC) with units in metres.

Details of Red Dog Resource Estimate

The Red Dog Resource Estimate incl udes a total of 96 diamond drill hole s totalling 21,970 metres drilled

by Northisle and previous operators through the en d of April 2026, of which 47 holes totalling 12,315

metres of assaying were completed under the direction of Northisle between June 2025 and April 2026.

Table 3 below summarizes the Red Dog Resource Estimate and shows the sensitivity of the estimate to cut-

oƯ assumptions.

Table 3: 2026 Red Dog Resource Estimate

In Situ Grade Contained Metal

NSR Cutoff Resource Tonnes NSR Cu Au Mo Re Cu Eq. Au Eq. Cu Au Mo Re Cu Eq. Au Eq. Strip

($/T) Class (000 T) ($/t) (%) (g/t) (ppm) (ppm) (%) (g/t) (mm lbs) (000s oz) (mm lbs) (000 lbs) (mm lbs) (000s oz) Ratio

$10.00 Indicated 90,961 48.30 0.19 0.21 32.51 0.20 0.42 0.40 380 628 7 40 846 1,183 2.26

Inferred 3,476 41.93 0.21 0.14 31.28 0.22 0.37 0.35 16 16 0 2 28 39

$11.00 Indicated 90,463 48.51 0.19 0.22 32.64 0.20 0.42 0.41 379 627 7 40 845 1,181 2.28

Inferred 3,421 42.43 0.21 0.14 31.59 0.22 0.37 0.36 16 16 0 2 28 39

$15.00 Indicated 87,802 49.58 0.19 0.22 33.25 0.20 0.43 0.42 376 622 6 39 839 1,172 2.39

Inferred 3,219 44.27 0.22 0.15 32.48 0.23 0.39 0.37 16 15 0 2 27 38

$20.00 Indicated 82,720 51.54 0.20 0.23 34.14 0.21 0.45 0.43 368 610 6 38 821 1,148 2.60

Inferred 2,799 48.26 0.24 0.16 31.99 0.22 0.42 0.40 15 15 0 1 26 36

Refer to Table 1 for Notes to the Resource Table.

Northisle Copper and Gold Inc. | 520 – 1050 West Pender St. | Vancouver, BC | V6E 3S7

www.northisle.ca | [email protected]

Table 4 below summarizes the shallow higher-grade core of the Red Dog deposit that is expected to be

included in the ﬁrst pushback of mining from Red Dog. This pit shell is de ﬁned by the 30% revenue factor

of the base case economic inputs deﬁning the resource pit shell.

Table 4: Red Dog Shallow Higher-Grade Core

In Situ Grade Contained Metal

Resource Tonnes NSR Cu Au Mo Re Cu Eq. Au Eq. Cu Au Cu Eq. Strip

Class (000 T) ($/t) (%) (g/t) (ppm) (ppm) (%) (g/t) (mm lbs) (000s oz) (mm lbs) Ratio

Indicated 26,579 70.50 0.25 0.34 50.34 0.30 0.62 0.59 144 293 361 0.11

Inferred 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 0 0

Refer to Table 1 for Notes to the Resource Table.

Figure 3 below shows the resource pit shell (grey) and the low strip-ratio, higher-grade conceptual initial

phase (gold) as summarized above. The modelled block grades shown are the NSR blocks above the

$11.00/tonne cut-oƯ.

Figure 3: Red Dog Resource Shell and Block Model Showing NSR/tonne

Coordinates are reported in UTM Zone 9 North (NAD83 CRS, VD CVG28BC) with units in metres.

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