NCX.V · 2025-02-19

NORTHISLE 2025 PEA INDICATES 29% AFTER-TAX IRR AND $2 BILLION NPV FOR STAGED DEVELOPMENT OF THE NORTH ISLAND PROJECT NPV of $3.8 Billion with an After-tax IRR of 45% at spot prices

Technical Reports (NI 43-101) Economic Studies

February 19, 2025 – All figures in C$ unless otherwise noted

TSX Venture Exchange Symbol: NCX

NORTHISLE 2025 PEA INDICATES 29% AFTER-TAX IRR AND $2 BILLION NPV FOR STAGED DEVELOPMENT OF THE NORTH ISLAND PROJECT NPV of $3.8 Billion with an After-tax IRR of 45% at spot prices Highlights:

The 2025 PEA outlines robust economics, unlocking copper value through gold
- Base Case: After-tax net present value (“NPV”) of $2 billion (US$1.5 billion) at a 7% discount rate, after-tax internal rate of return (“IRR”) of 29%, 1.9-year payback period and 29-year life of mine (“LOM”)
- After-tax NPV of $3.8 billion (US$2.6 billion) at 7%, after-tax IRR of 45% and a 1.4-year payback at spot prices
- Phase 1 average annual production of 200,000 ozs Au and 48mm lbs Cu over 5 years, with 157 million lbs Cu Eq. or approx. 307,000 ozs Au Eq. LOM
- LOM revenue of 48% copper, 45% Au, and 7% Mo at Base Case prices, and 50% Au, 44% Cu and 6% Mo at spot
- Phase 1 operating cash flow of $2 billion at Base Case prices supports rapid payback of 1.9 years and fully funds Phase 2 expansion capex
Among the lowest cost and capital intensity projects relative to peer group
- Two-phase approach at single plant site with Phase 1 at 40,000 tonnes per day (“tpd”), doubling to 80,000tpd
- NPV of $2.0 billion (US$1.5 billion) is 1.7 times initial capital investment of $1.1 billion (US$847 million) at Base Case pricing and 3.3 times initial capex at spot prices
- Phase 1 cash cost of US$763/oz Au Eq. or US$1.49/lb Cu Eq. sits in first quartile globallyⁱ
Long-term opportunity spanning 35-kilometer porphyry district
- 29-year mine plan includes only 753Mt of material of the 905Mt Indicated and 214Mt Inferred Resource
- New discovery at West Goodspeed, located within 1km of Red Dog, not included in current resource
- $7 million fully funded exploration program focused on expanding higher margin and grade northwest corridor
Furthers the Company’s sustainable development goals
- Reduced emissions from Phase 1 operations, increased electrification opportunities
- Estimated LOM carbon intensity among the lowest in Canada for open pit copper minesⁱⁱ

Vancouver, B.C. – Northisle Copper and Gold Inc. (TSX-V: NCX) (“Northisle” or the “Company”) is pleased to announce the positive results from a Preliminary Economic Assessment (the “2025 PEA”) for its 100% owned North Island Project (the “Project”) that demonstrate excellent economics from the staged development of the Project.

The 2025 PEA is based on a two-phase development of the Company’s 100% owned Northwest Expo and Red Dog deposits, followed by the Hushamu deposit concurrent with a plant expansion. The 2025 PEA considers the processing of 753 million tonnes of mineable material within three open pit deposits over a 29-year mine life. During the first phase, throughput is approximately 40,000tpd resulting in an initial capital expenditure of approximately $1.1 billion (US$849 million). Production includes a combination of gold doré and gold-rich copper concentrate. The second phase contemplates twinning the mill for a total of 80,000tpd in year 6 to produce copper concentrate (containing significant payable gold), additional gold doré, and a molybdenum concentrate (containing payable rhenium). Phase 1 delivers a short payback period of 1.9 years and strong operating cash flows (net of sustaining capital) of approximately $400 million per year that provide a strong return and fully fund Phase 2 construction starting in year 5 (see Figure 4).

Dale Corman, Chairman, Cornerstone Shareholder, and Mining Hall of Fame recipient, commented: “I have always believed that the North Island Project is among the most promising copper and gold projects in BC, and now, I believe it’s among the most promising in the world. The results of the PEA highlight the Project’s economic potential and the opportunity across our 35km district. Our team continues to make disciplined discoveries which we expect will continue to add value for shareholders.”

Sam Lee, President and CEO of Northisle added, “The 2025 PEA confirms our view that the North Island Project has the potential to be among the best copper and gold projects in Canada. Our approach to optimizing the PEA was built upon two strategic pillars: lowering the project capital intensity through a phased approach while maximizing overall project value and returns. Upon achieving these goals, we now have a project that sharply distinguishes itself from other more capital-intensive copper projects by unlocking our copper value through gold.

Of equal importance, we have just scratched the surface across our 35-kilometer porphyry district. Through our fully funded 2025 exploration program focused on the Northwest Corridor, we will test for the causative intrusion at Northwest Expo, seek to expand the footprint of West Goodspeed both along strike and via fault offsets, and in-fill West Goodspeed to enhance continuity. In our view, the combination of exploration potential and a robust development project at its core make the North Island Project one of Canada’s most compelling copper AND gold projects.

With continued support of our First Nations partners, the BC and Federal Government, our shareholders and other stakeholders, we look forward to our project providing meaningful benefits in the years and decades to come.”

Jagrup Brar, Minister of Mining and Critical Minerals stated “Responsible resource development of critical minerals in partnership with First Nations is proven to expedite mining projects in B.C. That’s why we are pleased to see Northisle continue to progress its North Island Project to unlock copper, one of Canada’s critical minerals. We look forward to working with Northisle on obtaining efficient permitting decisions.”

The Company will host a conference call and webcast on February 19, 2025 at 11:00 AM Eastern time (8:00 AM Pacific time). Details to access the call can be found below.

Key performance indicators are summarized in Table 1 below.

Table 1: 2025 Base Case Summary Project Metrics

Project Stage	Production						AISC							After-	After- tax NPV (7%)	After- tax IRR	GHG Emissions (kg CO 2 /lb.)
														tax
														Avg.
														Free
														Cash
														Flow
		Cu	Au (Koz)		Cu Eq.	Au Eq. (Koz)		Cu by-		Au by-	Cu Eq. (US$/lb)	Au Eq. (US$/oz)	$ mm		$ mm	%	Cu	Cu Eq.
		(mm			(mm			product		product
		lbs)			lbs)			(US$/lb)		(US$/oz)
Phase 1 (first 5 years) average	48		200	151		294	$(3.23)		$370		$1.83	$938	357		1,996	28.6	1.17	0.56
Life of mine (“LOM”) average	75		137	157		307	$0.47		$93		$2.41	$1,232	199

Note: Cu Eq. based on Base Case metal prices and includes molybdenum and gold. See Table 2 for details.

2025 PEA Summary

The 2025 PEA was prepared in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects (“NI43-101”) by Ausenco Engineering Canada ULC (“Ausenco”) in conjunction with an updated mine plan prepared by Moose Mountain Technical Services (“Moose Mountain”) and incorporates the previously announced integrated resource estimate for the North Island Project prepared by Moose Mountain (the “2024 Resource Estimate”). The 2025 PEA also includes an updated Mine Waste Storage Facility (“MWSF”) design prepared by Ausenco and updated metallurgical test work, also overseen by Ausenco. The Company plans to file the complete 2025 PEA report on SEDAR+ at www.sedarplus.ca within 45 days of this press release.

Table 2 summarizes the key findings of the 2025 PEA.

Table 2: 2025 PEA Economic Highlights

	Base Case Economics		Units		Base Case
Net Present Value (after tax NPV 7%)		$ millions		1,996
Net Present Value (after tax NPV 7%)		US$ millions		1,477
Internal Rate of Return		%		28.6
Payback		Years		1.9
Phase 1 Initial Capital Cost		$ millions		1,144 (US$847)
Phase 2 Expansion Capital		$ millions		693 (US$513)
Sustaining Capital Cost		$ millions		1,278 (US$946)
	Economic Assumptions		Units		Base Case
Copper		US$/lb		4.20
Gold		US$/oz		2,150
Molybdenum		US$/lb		21
Rhenium		US$/kg		1,950
CAD:USD Exchange Rate		US$/C$		0.74
	Base Case Annual Financial Metrics		Units		First 5 years		LOM
Average Annual Revenue		$ millions		855		902
Average Annual On-site Operating Costs		$ millions		279		411
Avg. Ann. Operating Cash Flow (after tax)		$ millions		418		290
Avg. Ann. Free Cash Flow (after tax)		$ millions		357		199

The 2025 PEA is preliminary in nature and includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves. There is no certainty that the projections described in the 2025 PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

Table 3 provides a summary of the key operating metrics from the 2025 PEA.

Table 3: 2025 PEA Operating Highlights

Operating Statistics	Units		Phase 1 (First 5	Phase 2	Avg. LOM
			Years)
Mine Life	Years	5		23.7	28.7
Annual Throughput	M tonnes	14.8		28.6	26.2
Waste to Processed Material	Waste:Processed Material	1.43		0.74	0.81
Total Copper Recoveries	%	86.7		79.3	80.1
Total Gold Recoveries	%	83.1		57.4	62.3
Total Molybdenum Recoveries	%	NA		51.4	51.4
Average Annual Payable Production
Copper	mm lbs	48		81	75
Gold	Koz	200		123	137
Molybdenum	Klbs	NA		2,763	2,282
Cu Eq.	mm lbs	NA		158	157
Au Eq.	Koz	294		309	307
C1 Cost – Cu Eq payable	$/lb	1.49		2.15	2.04
C1 Cost – Au Eq payable	$/oz	762		1,100	1,044
AISC – Cu Eq payable	$/lb	1.83		2.52	2.41
AISC – Au Eq payable	$/oz	938		1,291	1,232

CuEq = copper payable lbs + ((gold payable oz * gold price)/copper price) + ((molybdenum payable lbs *molybdenum price)/copper price)

AuEq = gold payable oz + ((copper payable lbs * copper price)/gold price) + ((molybdenum payable lbs *molybdenum price)/gold price)

Cash cost = operating costs + offsite costs – Rhenium credit AISC = cash cost + royalties + sustaining capital + closure capital Cu Eq. and Au Eq. calculated at Base Case metal prices

Economic Sensitivity

An economic analysis was conducted based on spot metal prices (the “Spot Price”) as of February 11, 2025 and assumed no changes to any other modifying factors.

Table 4: 2025 PEA Economic Highlights

	Spot Price Economics		Units		Spot Price1
Net Present Value (after tax NPV 7%)		$ millions		3,754
Net Present Value (after tax NPV 7%)		US$ millions		2,625
Internal Rate of Return		%		45.1
Payback		Years		1.4
Phase 1 Initial Capital Cost		$ millions		1,144 (US$847)
Phase 2 Expansion Capital		$ millions		693 (US$513)
Sustaining Capital Cost		$ millions		1,278 (US$946)
	Economic Assumptions		Units		Spot Price1
Copper		US$/lb		4.67
Gold		US$/oz		2,908
Molybdenum		US$/lb		21
Rhenium		US$/kg		2,417
CAD:USD Exchange Rate		US$/C$		0.70

1 – Spot price as of February 11^th, 2025

Table 5 summarizes the after-tax sensitivities of NPV and IRR to metal prices.

Table 5: 2025 PEA Post Tax Sensitivity Summary

		Post-Tax Sensitivity to Metal Price (C$M)
		Post-Tax NPV Sensitivity To Discount Rate ($M)					Post-Tax IRR Sensitivity To Discount Rate
Commodity Price				Spot Price	Commodity Price				Spot Price
Discount Rate	$1,974 (20%) (10%) – 10% 20% 3% 1,649 2,598 3,546 4,500 5,450 5% 1,160 1,903 2,642 3,384 4,121 7% 806 1,404 1,996 2,588 3,176 8% 665 1,207 1,742 2,276 2,805 10% 439 890 1,334 1,774 2,210			–	Discount Rate	$0 (20%) (10%) – 10% 20% 3.00% 16.6% 22.9% 28.6% 33.7% 38.6% 5.00% 16.6% 22.9% 28.6% 33.7% 38.6% 7.00% 16.6% 22.9% 28.6% 33.7% 38.6% 8.00% 16.6% 22.9% 28.6% 33.7% 38.6% 10.00% 16.6% 22.9% 28.6% 33.7% 38.6%			–
			1,649 2,598 3,546 4,500 5,450 1,160 1,903 2,642 3,384 4,121 806 1,404 1,996 2,588 3,176 665 1,207 1,742 2,276 2,805 439 890 1,334 1,774 2,210	6,299 4,814 3,754 3,337 2,667				16.6% 22.9% 28.6% 33.7% 38.6% 16.6% 22.9% 28.6% 33.7% 38.6% 16.6% 22.9% 28.6% 33.7% 38.6% 16.6% 22.9% 28.6% 33.7% 38.6% 16.6% 22.9% 28.6% 33.7% 38.6%	45.1% 45.1% 45.1% 45.1% 45.1%
		Post-Tax NPV Sensitivity To OPEX ($M)					Post-Tax IRR Sensitivity To OPEX
Commodity Price				Spot Price	Commodity Price				Spot Price
OPEX	$1,974 (20%) (10%) – 10% 20% (20%) 1,310 1,902 2,492 3,082 3,668 (10%) 1,059 1,654 2,244 2,835 3,423 – 806 1,404 1,996 2,588 3,176 10% 552 1,154 1,748 2,341 2,933 20% 294 904 1,501 2,094 2,686			–	OPEX	$0 (20%) (10%) – 10% 20% (20%) 21.2% 26.9% 32.2% 37.1% 41.8% (10%) 19.0% 24.9% 30.4% 35.4% 40.2% – 16.6% 22.9% 28.6% 33.7% 38.6% 10% 14.0% 20.6% 26.6% 32.0% 37.0% 20% 11.0% 18.3% 24.6% 30.2% 35.3%			–
			1,310 1,902 2,492 3,082 3,668 1,059 1,654 2,244 2,835 3,423 806 1,404 1,996 2,588 3,176 552 1,154 1,748 2,341 2,933 294 904 1,501 2,094 2,686	4,247 4,001 3,754 3,508 3,262				21.2% 26.9% 32.2% 37.1% 41.8% 19.0% 24.9% 30.4% 35.4% 40.2% 16.6% 22.9% 28.6% 33.7% 38.6% 14.0% 20.6% 26.6% 32.0% 37.0% 11.0% 18.3% 24.6% 30.2% 35.3%	48.0% 46.5% 45.1% 43.6% 42.0%
		Post-Tax NPV Sensitivity To Initial Capex ($M)					Post-Tax IRR Sensitivity To Initial Capex
Commodity Price				Spot Price	Commodity Price				Spot Price
Initial Capex	$1,974 (20%) (10%) – 10% 20% (20%) 988 1,581 2,173 2,760 3,350 (10%) 898 1,492 2,085 2,673 3,263 – 806 1,404 1,996 2,588 3,176 10% 715 1,314 1,910 2,500 3,092 20% 622 1,224 1,820 2,412 3,004			–	Initial Capex	$0 (20%) (10%) – 10% 20% (20%) 21.9% 29.5% 36.3% 42.5% 48.2% (10%) 18.9% 25.8% 32.0% 37.6% 42.9% – 16.6% 22.9% 28.6% 33.7% 38.6% 10% 14.7% 20.4% 25.7% 30.5% 35.1% 20% 13.2% 18.4% 23.4% 27.9% 32.1%			–
			988 1,581 2,173 2,760 3,350 898 1,492 2,085 2,673 3,263 806 1,404 1,996 2,588 3,176 715 1,314 1,910 2,500 3,092 622 1,224 1,820 2,412 3,004	3,929 3,841 3,754 3,667 3,580				21.9% 29.5% 36.3% 42.5% 48.2% 18.9% 25.8% 32.0% 37.6% 42.9% 16.6% 22.9% 28.6% 33.7% 38.6% 14.7% 20.4% 25.7% 30.5% 35.1% 13.2% 18.4% 23.4% 27.9% 32.1%	56.0% 50.0% 45.1% 41.0% 37.6%
		Post-Tax NPV Sensitivity To Recovery Mill ($M)					Post-Tax IRR Sensitivity To Recovery Mill
Commodity Price				Spot Price	Commodity Price				Spot Price
Recovery Mill	$1,974 (20%) (10%) – 10% 20% (20%) 85 623 1,141 1,651 2,159 (10%) 446 1,011 1,564 2,114 2,664 – 806 1,404 1,996 2,588 3,176 10% 1,204 1,839 2,473 3,103 3,733 20% 1,732 2,407 3,082 3,751 4,425			–	Recovery Mill	$0 (20%) (10%) – 10% 20% (20%) 8.1% 14.4% 19.9% 24.9% 29.6% (10%) 12.5% 18.7% 24.3% 29.5% 34.2% – 16.6% 22.9% 28.6% 33.7% 38.6% 10% 20.6% 26.9% 32.6% 37.9% 43.0% 20% 24.8% 31.0% 36.7% 42.1% 47.2%			–
			85 623 1,141 1,651 2,159 446 1,011 1,564 2,114 2,664 806 1,404 1,996 2,588 3,176 1,204 1,839 2,473 3,103 3,733 1,732 2,407 3,082 3,751 4,425	2,704 3,223 3,754 4,332 5,043				8.1% 14.4% 19.9% 24.9% 29.6% 12.5% 18.7% 24.3% 29.5% 34.2% 16.6% 22.9% 28.6% 33.7% 38.6% 20.6% 26.9% 32.6% 37.9% 43.0% 24.8% 31.0% 36.7% 42.1% 47.2%	35.5% 40.4% 45.1% 49.6% 54.1%
		Post-Tax NPV Sensitivity To Head Grade ($M)					Post-Tax IRR Sensitivity To Head Grade
Commodity Price				Spot Price	Commodity Price				Spot Price
Head Grade	$1,974 (20%) (10%) – 10% 20% (20%) (249) 298 778 1,248 1,712 (10%) 312 858 1,390 1,918 2,445 – 806 1,404 1,996 2,588 3,176 10% 1,288 1,946 2,603 3,255 3,908 20% 1,766 2,488 3,205 3,923 4,642			–	Head Grade	$0 (20%) (10%) – 10% 20% (20%) 3.4% 10.8% 16.3% 21.3% 25.9% (10%) 10.9% 17.2% 22.7% 27.8% 32.5% – 16.6% 22.9% 28.6% 33.7% 38.6% 10% 21.7% 28.1% 33.8% 39.3% 44.4% 20% 26.4% 32.9% 38.8% 44.4% 49.8%			–
			(249) 298 778 1,248 1,712 312 858 1,390 1,918 2,445 806 1,404 1,996 2,588 3,176 1,288 1,946 2,603 3,255 3,908 1,766 2,488 3,205 3,923 4,642	2,152 2,952 3,754 4,559 5,365				3.4% 10.8% 16.3% 21.3% 25.9% 10.9% 17.2% 22.7% 27.8% 32.5% 16.6% 22.9% 28.6% 33.7% 38.6% 21.7% 28.1% 33.8% 39.3% 44.4% 26.4% 32.9% 38.8% 44.4% 49.8%	31.5% 38.5% 45.1% 51.3% 57.2%

Note: FX sensitivity has only been applied to revenue in this study. Future studies will further model FX sensitivity. Spot Price is US$4.67/lb Cu, US$2,908/oz Au, US$21/lb Mo, US$2,417/kg Re and an FX rate of 0.70.

Figure 1: Sensitivity Summary Post-Tax NPV (7%)

3,500.0

3,000.0

2,500.0

2,000.0

1,500.0

1,000.0

500.0

– (25%) (20%) (15%) (10%) (5%) – 5% 10% 15% 20% 25%

Commodity Price (+/-%) Total Opex (+/-%) Initial Capex (+/-%)

Recovery (+/-%) Head Grade (+/-%)

Figure 2: Sensitivity Summary Post-Tax IRR

45.00%

40.00%

35.00%

30.00%

25.00%

20.00%

15.00%

10.00%

5.00%

– (25%) (20%) (15%) (10%) (5%) – 5% 10% 15% 20% 25%

Commodity Price (+/-%) Operating Cost (+/-%) Initial Capex (+/-%)

Recovery(+/-%) Head Grade (+/-%)

Figure 3: Annual Production Chart

300 35,000

30,000

25,000

20,000

15,000

10,000

5,000

– 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Year

Copper Equivalent Production Mill Feed

Figure 4: Annual Cumulative FCF Chart

1,200 6,000 Post-Tax CF - Phase 1 Post-Tax CF - Phase 2

Initial Capex Expansion Capex 1,000 5,000 Post-Tax Cumulative FCF

800 4,000

600 3,000

400 2,000

200 1,000

(200) (1,000)

(400) (2,000)

(600) (3,000) Phase 1 Phase 2 (800) (4,000) -2 -1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Year

Comparison to 2021 PEA

Table 6: Comparison of 2021 PEA to 2025 PEA

Information/Data Type	2021 PEA	2025 PEA
Economics	$1.1 billion Afetr-tax NPV (8%) and 19% Afetr-tax IRR	$2.0 billion Afetr-tax NPV (7%) and 29% Afetr-tax IRR
Initial Capital Expenditure	$1.4 billion	$1.1 billion (US$847 million)
Payback of initial capital expenditure	3.9 years	1.9 years, expansion capital expenditure paid out of after-
		tax free cash flow
Afetr-Tax Free Cash Flow	Average annual afetr-tax free cash flow of $321 million during the first 6 years, $224 million LOM	Average annual afetr-tax free cash flow (includes all capex)
		of $357m first 5 years, $199m LOM
AISC	US$2.01/lb Cu Eq over first 6 years, US$2.14/lb Cu Eq LOM
		US$1.83/lb Cu Eq over first 5 years, US$2.41/lb Cu Eq LOM
Annual Production	First 6-year average payable production of 112mm lbs Cu and 112 koz Au; LOM average payable production of 96mm lbs Cu and 100koz Au, including 1.0kt Mo	First 5-year average payable production of 200koz Au and
		48mm lbs Cu; LOM average annual payable production of
		75mm lbs Cu and 137 koz Au, plus 1.0kt Mo and Re credits
Mine Life	22 years	29 years
Mine Capacity	75 ktpd for Red Dog and Hushamu mine and mill	2 Stage production plan, 40 ktpd expanding to 80 ktpd to
		provide early processing of Au rich NW Expo material to
		significantly improve project economics
Processing and Metallurgy	Flotation of Red Dog and Hushamu material to produce Cu concentrate and Molybdenum concentrate	Flotation plus cyanide leach of rougher and cleaner (Ph 1)
		and cleaner (Ph 2) flotation tails to add 15-25%
		improvement in Au recovery by producing Au doré
Project Capital Expenditure	Single Phase initial capital - more difficult to finance	2 Phase production provides significantly reduced initial
		capital to facilitate project financing. Second phase
		expansion paid entirely out of free cash flow.

Information/Data Type		2021 PEA			2025 PEA
Pricing		Base Case	Spot Price	Base Discount to Spot	Base Case	Spot Price		Base Discount to Spot
Cu Price	US$/lb	3.25	3.51	7%	4.20	4.67		10%
Au Price	US$/oz	1,650	1,835	10%	2,150	2,908		26%
Mo Price	US$/lb	10	10	0%	21	21		0%
Re Price	US$/kg	1,256	1,256	0%	1,950	2,417		19%
Exchange Rate	USD/CAD	0.75	0.75	0%	0.74	0.70		(6%)
Production		LOM			First 5 years		LOM
Mine Life	Years	22			5		28.7
Total Mill Feed	kt	600,359			74,133		752,164
Strip Ratio	Waste : Processed	0.71			1.43		0.81
Mill Design Capacity	tpd	75,000			40,000		80,000
Processing and Metallurgy		Cu and Au flotation to produce Cu con and separate Moly con			Cu and Au flotation to produce Cu con and separate Moly con, cyanide leach of NW Expo and Red Dog ore rougher and cleaner tails, and Hushamu cleaner tails
Total Copper Recovery	%	86%			86.7		80.1
Total Gold Recovery	%	47%			83.1		62.3
Total Molybdenum Recovery	%	60%			51.4		51.4
Average Annual Cu Production	mm lbs	96			48		75
Average Annual Au Production	koz	100			200		137
Average Annual Mo Production	kt	1.1			N/A		1.0
Annual CuEq Production	mm lbs	156			151		157
Total Cu Recovered	mm lbs	2,035			240		2,168
Total Au Recovered	koz	2,143			1,002		3,932
Total Mo Recovered	kt	25			N/A		30
Total CuEq Recovered	mm lbs	3,430			753		4,509
Operating Cost
Mining Cost	$/t mined	2.32			3.16		3.12
Processing Cost	$/t milled	5.58			10.39		9.36
G&A Cost	$/t milled	0.38			1.25		0.68

Smelting and Refining Cost	$/t milled	1.32	1.65	0.81
Total Operating Cost	$/t milled	11.12	19.68	15.69
Cash Cost	US$/lb CuEq	2.09	1.49	2.04
AISC	US$/lb CuEq	2.14	1.83	2.41
Capital Costs
Project Capital Expenditure	$ millions	1,442	1,144	1,837
Sustaining Capital	$ millions	197	325	1,278
Closure Cost	$ millions	71	N/A	367
Salvage Cost	$ millions	25	N/A	171
Financials
Average Annual Operating Cash			411	279
	$ millions	n/a
Flow After-tax
Average Annual Free Cash Flow			357	199
	$ millions	224
Afetr-tax
NPV afetr-tax	$ billions	1.06 (8%)	N/A	2.00 (7%)
IRR - afetr-tax	%	19	N/A	28.6
Payback	Years	3.9	N/A	1.9

Sustainability

Northisle has incorporated a focus on sustainability into its core strategy, emphasizing the monitoring, disclosure and improvement of ESG performance, recognizing it as equally important to the Company’s success as operating metrics. As a result, Northisle has summarized updated preliminary sustainability metrics for the North Island Project in Table 7 below.

Table 7: Preliminary Sustainability Metrics

	Sustainability Statistics		Units		LOM Total / Avg.
Direct job creation (permanent)		FTE		428
	Site Energy Consumption
Fuel (annual)		000s liters		35,470
Electricity (annual)		MWh		706,950
Energy Intensity		kWh / lb CuEq		4.55
	Environmental
Net water consumption		liters / lb CuEq		255
GHG Emissions – Scope 1		kg CO2e / lb CuEq		0.56
	Total Material to MWSF		MT		1,176

The above sustainability metrics were determined on a preliminary basis by referencing publicly available benchmarks for emissions related to key project energy sources as well as physical quantities estimated in the 2025 PEA. The selected metrics will evolve as the project is developed, to incorporate additional measures of ESG performance.

Permitting and Environment

The Project will likely require authorization under the Canadian Impact Assessment Act (IAA) and the British Columbia Environmental Assessment Act (EAA). There is currently a legal mechanism for cooperation between provincial and federal processes which allows projects to adopt coordination, substitution or joint panel review. The environmental assessment processes typically take three to five years. It should however be noted that the Impact Assessment Cooperation Agreement Between Canada and British Columbia is up for renewal in 2025.

Free, prior and informed consent, in line with the United Nations Declaration on the Rights of Indigenous Peoples (UNDRIP), is a foundation of the approach to environmental assessments (EA) in BC. Indigenous Nations play a critical role in scoping and reviewing projects that could impact their Rights or Indigenous Interests. The EAA requires consent from Indigenous groups that are identified as a “Participating Indigenous Nation”, and in some cases they may also be identified as an additional regulator. Indigenous Nations also have the option to undertake Indigenous-led assessments as Participating Indigenous Nations under 19(4) of the EAA. This may affect the EA process and timeline for the Project. Additional federal and provincial authorizations will likely be required for the Project and could take three years to obtain but would be pursued in parallel with the EA.

Preliminary baseline field surveys conducted for the Project include fisheries, hydrology, climate, and wildlife. Additional desktop studies have included these disciplines and hydrogeology. Additional baseline studies are planned for 2025.

Stakeholder Engagement

The Project is located within the separately claimed traditional territories of the Quatsino First Nation (the “Quatsino”), the Tlatlasikwala First Nation (the “Tlatlasikwala”), and the Kwakiutl First Nation (the “Kwakiutl”). Each respective First Nation is the best source for detailed information about its traditional territory. The Company has initiated discussions and maintains an ongoing dialogue with the Quatsino, the Tlatlasikwala and the Kwakiutl, as well as other First Nations and communities in proximity to the Project. The Company has and continues to actively employ members of local First Nations and other communities, and First Nations and local individuals and businesses.

In addition to consulting regularly with each First Nation, the Company has entered into consent-based exploration agreements and successive renewals with Quatsino and Tlatlasikwala in respect of exploration programs conducted within their territory. These agreements provide for an open, honest, transparent and fair process through which the Company can conduct certain activities to determine the viability of developing mines, mills, or related facilities for the commercial production of minerals in a manner which recognizes the rights of the respective First Nations.

The Company intends to continue to engage proactively with all potentially impacted parties.

Opportunities

The 2025 PEA demonstrates the potential for further development of the North Island Project and indicates several additional opportunities for further study which may contribute to further enhanced value, including:

Optimization of the mineral process flowsheet: Once additional metallurgical testing is completed, the following can be confirmed: Optimum grind size selection and comminution selection, optimum regrind size for each deposit and regrind technology selection, optimization of leaching and absorption retention time and optimum source of leaching and cyanide detoxification oxygen.
Additional step-out and in-fill drilling: There is potential for additional resources at West Goodspeed, located less than a kilometer from Red Dog, as well as potential extension of all the known deposits within the North Island Project, thus increasing the mineralized material available for development, including testing for the causative intrusion source for the higher-grade mineralization at Northwest Expo. In-fill drilling of the three currently defined deposits could further increase the indicated resource material. A fully funded exploration program is being advanced for 2025.
Mining related test work: The current PEA applies assumptions based on existing test work which effect the pit design, and refinement of these may increase the indicated resource material. These include improved geotechnical and hydrogeological test work, geochemical test work, as well as market studies to outline potential capital for project financing.
Reduce carbon emissions: High-level calculations at the time of this release indicate that converting the proposed diesel mine fleet to an electric fleet has the potential to result in avoidance of compliance payments for carbon emission exceedances and may result in payment for project credits. This depends on the strength of the BC OBPS market and may justify the cost of electrifying the fleet.
Optimization of site infrastructure: Optimizing the plant location to reduce tailings pumping equipment and cost, utilising regenerative conveyors to add power to the overall system and reduce power consumption.
Optimizing permitting schedule: There are opportunities to optimize the overall permitting schedule by advancing permitting while the EA process is underway. Although major permits cannot be issued for projects prior to the receipt of an Environmental Assessment Certificate, the EA and permitting processes can advance in parallel.

Next Steps

With the completion of the 2025 PEA, Northisle intends to continue to advance the North Island Project. Key next steps and milestones include:

Northisle will continue to proactively engage with First Nations, local communities, government and key project stakeholders in support of the responsible development of the Project;
Complete the drilling program including infill and step out drilling at Northwest Expo, infill drilling at Red Dog, and resource definition drilling and step out at West Goodspeed;
Conduct plant site and MWSF site condemnation drilling;
Initiate additional environmental baseline work;
Conduct additional metallurgical test work to support the prefeasibility study;
Conduct geotechnical investigations for open pit design, process plant mill foundation design, and MWSF dam design; and
Commence a Prefeasibility Study.

A high-level project milestone schedule is provided in Figure 5.

Figure 5: Project Milestones

Milestones Exploration First Nations and Stakeholder Consultation Complete PEA	-6	-5	-4	-3	-2	-1	1
Expand Environmental Baseline Programs
Complete PFS
Complete FS
Submit Draft EIS
Submit Final EIS
Complete Engineering and Procurement
EA Approval
MA / EMA Permit Receipt
Signed IBAs Complete Construction
Initial Production

2025 Exploration Overview

Northisle is currently in the final stages of planning its 2025 exploration program. The fully funded $7 million program will be focused on enhanced understanding of higher-grade, higher-margin potential in the vicinity of Northwest Expo and West Goodspeed, an area which is now being identified as the “Northwest Corridor”. To date, the discoveries in this area have improved overall project resource grade and margin and have generally been near surface, presenting a compelling option for further improving the North Island Project. The 2025 focus areas are highlighted in Figure 6, and the Company expects to announce further details on the program once available.

Figure 6: 2025 Exploration Focus Areas

Webcast Details

The Company will host a conference call on February 19, 2025 at 11:00 AM Eastern time (8:00 AM Pacific time). Details to access the call live are as follows:

Via telephone, by calling +1-844-763-8274 toll free in North America, and +1-647-484-8814 internationally
Via webcast at: Webcast

The webcast will be archived for 6 months following the call at the above-noted link and on the Company’s website.

2025 PEA Details

The 2025 PEA is a comprehensive re-envisioning of the North Island Project built around several primary project goals, including:

Consider staged development to reduce initial capital costs while maintaining optionality for a larger, long-lived operation
Reconsider metallurgical approach to account for higher gold grades in the Northwest Expo and Red Dog pits
When evaluating trade-offs, select the option with the highest overall return that addresses the capital criteria
Minimize life-cycle impacts, specifically on a per unit produced basis

Changes to the Project design were extensive, including:

← Back to feed