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Gunnison Copper Announces Updated Preliminary Economic Assessment of its Flagship Gunnison Copper Project Reporting Post-Tax NPV8 of US$2.0 Billion

Economic Studies

NEWS RELEASE

Gunnison Copper Announces Updated Preliminary Economic Assessment of its

Flagship Gunnison Copper Project Reporting Post-Tax NPV8 of US$2.0 Billion

February 25, 2026

Gunnison Copper Corp. (TSX: GCU) (OTCQB: GCUMF) (FSE: 3XS0) (“Gunnison” or the “Company”) is

pleased to announce the results of an updated NI 43-101 Preliminary Economic Assessment ("PEA" or “2026

PEA”) on its 100%-owned Gunnison Copper Project in the Cochise Mining District, Arizona, United States

(“Gunnison Project”). The PEA supersedes the previous PEA on the Gunnison Project released in December

2024 (the “2024 PEA”) in all respects. All dollar amounts are in US dollars and "tons" refer to U.S. short tons

(1 short ton equals approximately 0.91 metric tonnes or 2000 lbs).

Highlights:

 Conventional open pit, heap leach, SX/EW operation producing 99.999% pure copper cathode

intended to supply United States energy, data center, manufacturing, and defense supply chains

 Straightforward mine plan consists primarily of oxide copper mineralized material with a life of

mine material placed on the leach pad of 541 million tons at 0.43% total copper grade, including

25 million tons at 0.85% total copper grade from the Strong & Harris satellite deposit

 Primary crushing on all, and secondary crushing on some material to improve copper recoveries

 Average annual copper cathode production of 174 million pounds (“lbs”) (87 thousand tons) for the

first 15 years; enough to potentially supply over 11% of the current United States domestic refined

copper metal production from mineralized material1. Total copper produced 3.2 billion lbs over a

21 year mine life.

 Cash costs of $1.69, Sustaining Cash Costs of $2.00, and All-In Sustaining Cash Costs of $2.06

per pound of copper produced are in the lower half of the cost curve for copper mines globally

 Robust project economics in a variety of copper price environments, including $4.60/lb base case:

Copper Price Assumption: $4.60/lb Cu Consensus $5.75/lb Cu SPOT2

NPV8 (after-tax) $M 1,952 3,219

IRR (after-tax) % 22.7% 32.0%

Payback (after-tax) #Years 3.9 2.6

Avg Annual Free Cash Flow (Y1-Y15) $M 366 514

 High purity limestone overburden, previously treated as waste, is now used to produce a cement

co-product to alleviate the regional cement supply deficit adding $130M NPV8%

 Significant economic impact to Cochise County, State of Arizona, and the United States nationally

through creation of over 53,000 jobs, $544 million in state and local county taxes, $1.37 billion in

federal taxes, and $14.6 billion in total economic output3

1 Based on USGS reported 2025 primary refined copper production of 790Ktons; 2 COMEX spot price at Feb 22, 2026

3Independent Economic Impact Study conducted by the Eller Partnerships Office at the University of Arizona Oct’25

2

The 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 conclusions reached in the PEA will be realized. Mineral

resources that are not mineral reserves do not have demonstrated economic viability.

Dr. Stephen Twyerould, CEO, commented, “ The updated PEA underscores the scale and compelling

economics of the Gunnison Copper Project, positioning it as a significant future supplier to the American

copper market and a key contributor to the domestic supply shortfall. At a consensus copper price of $4.60

per pound, the Project delivers an after-tax NPV8 of approximately US$2.0 billion, a 23% IRR, and an

attractive 3.9 year payback, positioning Gunnison as one of the most financially compelling copper

development projects in the United States. Importantly, 83% of the $692 million increase in NPV8% versus

our 2024 preliminary economic assessment study is driven by operational enhancements within our control,

including the addition of the high-grade Strong & Harris satellite deposit, material sorting, cement and

limestone co-products, and optimization initiatives. With average annual production of 174 million pounds

of 99.999% pure copper cathode in the first 15 years, lower-half-of-the-cost-curve operating metrics, and

significant leverage to copper prices, we believe Gunnison offers shareholders meaningful exposure to a

large-scale, long-life U.S. copper asset as we advance toward Pre-Feasibility, permitting, and project

financing.”

Table 1: Key Valuation Metrics at $4.60/lb Copper Price Base Case

Valuation Metrics (Unlevered) Unit 2026 PEA

Net Present Value @ 8% (after-tax) $ millions 1,952

Net Present Value @ 10% (after-tax) $ millions 1,419

Internal Rate of return (after-tax) % 22.7

Payback Period # years 3.9

EBITDA1 (annual average Y1-Y15) $ millions 488

EBITDA1 (annual average Y1-Y21) $ millions 435

Free Cash Flow1 (annual average Y1-Y15) $ millions 366

Free Cash Flow1 (annual average Y1-Y21) $ millions 329

1. Non-IFRS financial measure; see “Non-IFRS Financial Measures”.

Table 2: Key Project Metrics

Project Metrics Unit 2026 PEA

Construction Period # months 24

Life of Mine # years 21

Strip Ratio Waste : Feed 2.56

Mineralized Material Mined million tons 641

High Purity Limestone Mined million tons 133

Alluvium-Gravel Waste Mined million tons 1,007

Hard-Rock Waste Mined million tons 501

Copper Grade of Material Placed on Leach Pad % CuT 0.43%

Annual Crusher Throughput (max) million tons 40

Copper Recovery - Global % CuT 68.0%

Oxide / Enriched Recoveries % CuTSol 90.2%

Primary Sulfide Recoveries (years 10 to 21) % CuSu 59.9%

Recovered Copper Cathode million lbs 3,187

Average Annual Copper Production (years 1-15) million lbs

000’s tons

174

87

Initial Capital (including contingency) $ millions 1,544

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Project Metrics Unit 2026 PEA

Initial Capital Excluding Acid Plant $ millions 1,261

Capital Intensity Excluding Acid Plant1 $/ton Cu Capacity 14,278

Profitability Ratio NPV8% / Initial Capex 1.3

Expansion Capital (including contingency)2 $ millions 682

Sustaining Capital3 $ millions 613

Cash Cost (C1)4 $/lb Cu 1.69

Sustaining Cash Cost5 $/lb Cu 2.00

All-In Sustaining Cash Cost6 $/lb Cu 2.06

1. Capital intensity is calculated as initial capital excluding acid plant, $1,261M, divided by maximum annual copper

cathode plant capacity 88.3 Ktons

2. Expansion capital is expenditures to either build new facilities, for example the cement plant built in years 4-5, or to

expand the capacity of initial facilities, for example increased capacity of leach pad

3. Sustaining Capital are expenditures to maintain initial facilities. Includes $186 million in deferred stripping costs.

Includes sustaining capital for both the copper plant and the cement plant

4. Cash Cost includes mine operating, crushing and leaching, process plant operating, and general and

administrative costs ("G&A")

5. Sustaining Cost includes Cash Cost, Sustaining Capex, Deferred Stripping, and Royalties

6. All-In Sustaining Cost (AISC) includes Sustaining Cost, Property Taxes, Severance Taxes, and Closure Costs. It

excludes expansion and initial capital, and income taxes

The PEA was completed by M3 Engineering & Technology Corporation ("M3") of Tucson, AZ and is effective

as of February 22, 2026. The Technical Report (the "Report") summarizing the results of the PEA and prepared

in accordance with National Instrument ("NI") 43-101, will be filed on SEDAR+ and GCC's website within 45

days of this news release.

Updated Preliminary Economic Assessment Summary

The Project is in Cochise County, Arizona, approximately 65 miles east of Tucson and is held or controlled

100% by GCC. GCC has a successful track record of permitting and community relations. This, along with

the fact that the Gunnison open pit has no federal permitting nexus, on flat ground with no identified

endangered or threatened species or habitat, and no historical, archaeological, or Native American artefacts

identified in prior studies, indicates the Company's prior permitting track record can be maintained.

Key Changes Versus the 2024 PEA

Key changes versus the 2024 PEA include various price deck changes beyond the control of management,

such as the change in long-term copper price and various operating and capital cost escalation from 2024

to 2026, as well as non-price deck changes, including improvements such as mining the high-grade Strong

& Harris satellite deposit.

Net Present Value at 8.00% discount rate is the selected metric to explain the changes since the previous

PEA as this metric best captures the total economic return to the Company of the Gunnison Project.

Refer to the chart and text below for explanations of the change in valuation versus the 2024 PEA.

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Chart 1: Change in Net Present Value 8.00% (NPV8%) - 2026 PEA versus 2024 PEA ($M)

Note: NPV8% variance bars should be considered approximations and include an element of estimation and interpretation. Cross

correlations between variable changes may not be fully captured in each bar due to the sequence of applying changes in the financial

model and other supplementary calculations performed for variables not directly changeable in the financial model.

The 2026 PEA NPV8% of $1,952M is an increase of $692M (+55%) from the 2024 PEA NPV8% of $1,260M.

The increase is comprised of Price Deck changes of $117M, 17% of the increase, and Non-Price Deck

changes of $576M, the remaining 83% of the increase. The following explains the key changes in more detail:

Price Deck Changes $117M – The main driver is the increase in long-term consensus copper price from

$4.10/lb in the 2024 study to $4.60/lb in the 2026 study. Management uses analyst consensus given the

extensive knowledge and expertise of the institutions involved and the overall reliance of the market and

investors on consensus pricing. Acid, Sulfur, and Diesel prices were calculated on a delivered basis to site

based on data purchased from leading industry consultants, actual delivered to site pricing, and direct

discussions with logistics and commodity producers in the region. Mining opex, plant opex, and mining fleet

escalation is based on inflation and other factors to escalate pricing from 2024 to 2026 real dollars and

includes direct quotes from equipment manufacturers and service providers. Mining opex escalation also

includes the impact of mining additional more costly blocks, due primarily to increased stripping

requirements, from the bigger Gunnison main pit shell that the higher copper price makes economic to mine

versus the smaller pit shell in the 2024 study.

Strong & Harris Satellite Deposit $189M – This satellite deposit, located only 1.9 miles from the processing

plant, adds over 25 Mtons of high-grade material to the leach pad at 0.85% total copper grade to the

processing plan over three years (Y11-Y13). Given the mining fleet and plant costs are fully supported

already by the Gunnison Open Pit economics, the addition of the Strong & Harris material results in a

significant NPV8% increase, extension of mine life, and increase in the leach pad head grade. No credits for

zinc or silver are included in the new Strong and Harris mine and processing plan but could be considered

an opportunity for later with additional processing infrastructure. As Strong & Harris is now included within

the PEA, the prior technical report filed on SEDAR at www.sedar.com entitled: “Estimated Mineral

Resources and Preliminary Economic Analysis, Strong and Harris Copper-Zinc-Silver Project, Cochise

County, Arizona” dated effective of September 9, 2021 has been superseded and is no longer a current

technical report.

Material Sorter $84M – The mineralized Material Sorting equipment uses optical sensors to detect non-

mineralized material amongst the crushed material prior to stacking on the leach pad and diverts it to waste.

This reduces significantly the inclusion of non-mineralized material on the leach pad, thereby increasing the

leached head grade and reducing acid consumption. In total, 97.7 Mtons of oxide material and 3.1Mtons of

sulfide material is sorted to the waste stream over the life of mine, reducing mineralized material stacked

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and leached from 641.5 Mtons mined to 540.7 Mtons leached. The direct costs in initial capital for the

equipment is $205.4M and the operating costs are $0.86/ton of mineralized material sorted and leached.

Only the Martin and similar formations are included in the Material Sorting profile.

Geotechnical & Pit Slope $41M – Samples were collected in 2025 of the alluvium/conglomerate overburden

at Gunnison as part of the HVA program. Their strength and geotechnical characters were analyzed and

interpreted resulting in steeper pit walls than the previous study in 2024. In the alluvial overburden in 2024

the pit wall angles were determined to be 42 degrees, however the weakly cemented conglomerate

component was determined to range from 45 to 49 degrees increasing in steepness with depth.

Acid Plant $19M – Due to reductions in total acid consumption in the 2026 PEA versus the 2024 PEA, the

acid plant capacity was reduced by 10%, from 3,000 to 2,700 tons per day of acid production, along with

other beneficial design modifications resulted in savings of $73M in initial capex. A decrease in profit per unit

on third party acid sales partially offsets this improvement, due to higher operating costs.

Autonomous Haul Trucks $14M – Autonomous Haulage Systems (AHS) have become an accepted mining

tool for modern mines. The effect of lowering operating costs is greater than the additional capital required

for AHS. The trucks last longer, require less maintenance and are more efficient in delivering expected

production rates.

Cement $130M and Limestone $21M Coproducts– In 2025, drilling and lab testing confirmed the limestone

overburden on top of the Gunnison Pit to be a very high purity limestone suitable for producing several

saleable products. Based on the specifications of the limestone determined by the lab testing, and market

studies conducted by third party consultant firm Burgex, it was determined the highest and best use of the

limestone is to process it into cement for sale into local and regional markets up to the annual amount the

market is in deficit. Local market studies indicate a current deficit of over 1M tons of cement that is currently

filled by foreign Mexican production with high freight costs and tariffs. As a result, a cement plant can be

constructed with an output capacity of 1M tons of cement per year at an initial capital cost of $326M and it

will sell cement for $157.21/ton. The plant will be constructed in Years 4 and 5 after full payback on initial

capex has been reached and cumulative free cash flow is sufficient to pay for the cement plant capex. The

rail facility included in the capex has a dedicated outbound capacity of 3M tons per year. Given 1M tons of

cement will be sold per year, 2M tons of unrefined high grade limestone will also be sold to third parties at a

price of $4.80/ton. The overall limestone overburden, at 133M tons, is a very large and special discovery and

will continue to operate post Y21, the final year of copper production, until the resource is completely

depleted in Y70. Opportunity exists for future expansion of the cement plant.

Tax Depreciation Rule Changes $30M – The One Big Beautiful Bill Act of 2025 permanently extended the

Bonus Depreciation tax rule that permits 100% deduction of tangible property with a recovery period of 20

years or less, and other qualified improvement property, in the year of expenditure. This accelerated

depreciation reduces cash income taxes paid in the earlier years of the project, improving NPV8%. The same

total cash taxes are paid over the life of the mine but now are been paid later due to the accelerated

deductions.

Mining Fleet Leasing $23M – The initial mining fleet is now assumed to be capital leased with interest only

payments during the construction period that increases the NPV, partially offset by a 125 bps higher lease

rate premium included in the lease for this feature. Mining fleet purchases included in sustaining capex are

now also assumed to be leased with regular payment terms.

Other Non-Price Deck Changes $23M – All other changes

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Financial Analysis

The PEA base case generates an after-tax Net Present Value of approximately $2.0 billion (at a discount rate

of 8%) and an Internal Rate of Return (IRR) of 22.7%. This financial analysis is based on a non-levered cash

flow model, revenues and costs priced in 2026 real US dollars, mid period discounting, and a valuation date

set at the start of Project construction. The following tables detail key financial model inputs.

Table 3: Price Deck

Price Deck Inputs Unit 2026 PEA

Copper Price $/lb 4.60

Net Copper Premium $/lb 0.04

Molten Sulfur Delivered – Purchases $/ton 160.00

Sulfuric Acid Delivered – Purchases $/ton 210.00

Sulfuric Acid Delivered – Sales $/ton 190.00

Diesel Delivered $/gallon 2.96

Propane Delivered $/gallon 2.00

Cement – Sales $/ton 157.21

Limestone – Sales $/ton 4.80

Power – Purchases & Sales $/kWh 0.079

Price Deck Notes:

 Copper price of $4.60/lb is based on analyst consensus pricing as of February 3, 2026

 Net copper premium of $0.04/lb (metal premium $0.115/lb, or 2.5% of copper price, less freight to

customer of $0.0725/lb)

 Acid buying price of $210/ton if acid is required above the acid plant's capacity, and an acid selling

price of $190/ton if excess acid is produced in any specific year. The acid selling price includes the

cost of truck delivery from the Gunnison site to assumed local purchasers

 The acid plant generates electricity equivalent to a 26 MW power plant. The power generated during

the life of the copper mine is completely used in the operation of the mine and process plant.

Following the closure of the copper mine, power generation will be completely used by the cement

plant

Table 4: Capital Expenditures

The capital cost estimates for this PEA, shown in table below, were developed with a -25% to +30% accuracy.

The Company has used an overall contingency of 20% in accordance with Association of the Advancement

of Cost Engineering International (AACE) Class 5 estimate guidelines.

Capital Expenditures Inputs Unit Initial Expansion Sustaining

Direct Costs - Mine Costs $ million 294.0 - 77.7

Direct Costs - Deferred Stripping $ million - 185.7

Direct Costs - Leach Pad $ million 76.1 201.2 -

Direct Costs - Crusher $ million 53.3 - -

Direct Costs - Ore Sorting $ million 205.4 - -

Direct Costs - SX-EX $ million 186.0 - -

Direct Costs – Freight $ million 52.4 16.0 -

Direct Costs - Subtotal $ million 867.0 217.3 263.4

Indirect Costs $ million 148.0 32.9 -

Owner's Costs $ million 65.6 - -

Contingency $ million 127.5 39.2

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Capital Expenditures Inputs Unit Initial Expansion Sustaining

Subtotal $ million 1,208.1 289.4 263.4

Acid Plant $ million 282.3 - -

Infrastructure $ million 53.2 10.8 -

Sulfide Plant $ million - 56.6 -

Cement Plant $ million - 325.5 349.5

Total CAPEX $ million 1,543.7 682.3 612.9

Capital Expenditures Notes:

 The cement plant is built over years 4 and 5, following payback on initial capex investment. Sufficient

free cash flow is generated in year 4 post-payback to fully pay for the cement plant capex

Table 5: Operating Expenditures – Copper

Operating Expenditures – Copper

Inputs

$ Millions

Total

$/lb Cu

Produced $/Ton

Mining - Before Deferred Stripping 4,179 1.31 $/ton mined

$/ton mined

$/ton mined

1.83

Mining - Limestone Credits (231) (0.07) (0.10)

Mining - Deferred Stripping (186) (0.06) (0.08)

Mining - Subtotal 3,762 1.18 $/ton mined 1.65

Processing - Heap Leach 1,146 0.36 $/ton leached 2.12

Processing - Material Sorting 218 0.07 $/ton sorted 0.86

Processing - SX/EW 636 0.20 $/ton leached 1.18

Processing - Subtotal 2,000 0.63 $/ton leached 3.70

G&A - Onsite 142 0.04 $/ton mined 0.22

G&A - Limestone Credits (6) (0.00) $/ton mined (0.01)

Byproduct Credits – Acid Sales (503) (0.16) $/ton mined (0.78)

Cash Cost (C1) 5,396 1.69 $/ton mined 8.41

Sustaining Capex - Mining 78 0.02 $/ton mined 0.12

Sustaining Capex - Deferred Stripping 186 0.06 $/ton mined 0.29

Sustaining Capex - Subtotal 263 0.08 $/ton mined 0.41

Royalties 715 0.22 $/ton mined 1.11

Sustaining Cash Cost 6,374 2.00 $/ton mined 9.94

Taxes - Property Tax 64 0.02 $/ton mined 0.10

Taxes - Severance Tax 109 0.03 $/ton mined 0.17

Taxes - Subtotal 173 0.05 $/ton mined 0.27

Closure - Reclamation (Inc. Surety Bond) 72 0.02 $/ton mined 0.11

Closure - Salvage Value (63) (0.02) $/ton mined (0.10)

Closure - Subtotal 9 0.00 $/ton mined 0.01

All-In Sustaining Cost (AISC) 6,556 2.06 $/ton mined 10.22

1. This table contains Non-IFRS financial measures; see “Non-IFRS Financial Measures”.

Operating Expenditures – Copper Notes:

 Mining operating cost estimates, prepared by Independent Mining Consultants (“IMC”), are based

on an owner's team managing mining activities, using an owner-operator model. Process operating

cost estimates and G&A cost estimates were prepared by M3, as summarized in the table above

(note numbers may not visually add due to rounding)

 The operating site includes numerous infrastructure and location advantages including:

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o Union Pacific rail line right next to the property with a 2 km rail spur envisioned

o High voltage power lines with clean power from SSVEC

o Close to local and regional labor pools of Benson, Willcox, and Tucson

o Flat to slightly undulating land is conducive for development

o Deposit is within an enclosed hydrological basin; therefore no 404 permit is required

o No identified endangered flora or fauna on the property

 Limestone credits are the costs of mining and G&A that are attributable to the limestone/cement co-

product cost and are included in the Cement operating Expenditures table below

Table 6: Operating Expenditures – Cement

Operating Expenditures –Cement Inputs $ Millions

Total

$/Ton

Limestone

Processed

$/ton

Cement

Produced

Mining 231 2.89 3.53

Processing - Raw Materials Processing 612 7.69 9.38

Processing - Additives 768 9.64 11.76

Processing - Energy 1,536 19.28 23.52

Processing - Labor & Staff 718 9.01 10.99

Processing - Maintenance 811 10.18 12.42

Processing - Other Costs 693 8.70 10.61

Processing - Subtotal 5,137 64.49 78.68

Freight 845 10.61 12.95

G&A - Onsite 408 5.12 6.25

G&A - Mining - Portion out of Cu 6 0.07 0.09

Byproduct Credits - Limestone - Royalty Sales (255) (3.20) (3.90)

Cash Cost (C1) 6,372 79.99 97.59

Sustaining Capex 350 4.39 5.35

Sustaining Cash Cost 6,722 84.38 102.95

Taxes - Property Tax 34 0.43 0.52

Closure - Reclamation (Inc. Security Bonds) 59 0.74 0.90

Closure - Salvage Value (26) (0.33) (0.40)

Closure - Subtotal 33 0.41 0.50

All-In Sustaining Cost (AISC) 6,789 85.22 103.97

1. This table contains Non-IFRS financial measures; see “Non-IFRS Financial Measures”.

Operating Expenditures – Cement Notes:

 Energy is the most significant operational expense for cement production, estimated at $23.52 per

ton (30 percent of total operating expenses) of cement produced. This is consistent with the energy-

intensive nature of the pyro processing (kiln) and grinding stages. Energy consumption is modeled

using industry benchmarks of 3.5 gigajoules per ton of clinker (thermal) associated with a modern

dry-process rotary kiln using a five-stage preheater, and 110 kilowatt-hours per ton of cement

(electrical).

 The model estimates additive costs at $11.76 per ton (15 percent of total operating expenses). This

covers the procurement and delivery of materials added to the clinker, including gypsum (to control

setting time) and supplementary cementitious materials (SCMs) such as fly ash, slag or pozzolans

used to produce blended cements (e.g., Type IL). It also includes potential inputs like clay or sand to

adjust chemistry