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Gunnison Copper Project PEA Technical Report Reporting Post-Tax NPV8 of ~US$2.0 Billion and IRR of 22.5% is now Filed

Technical Reports (NI 43-101) Economic Studies

NEWS RELEASE

Gunnison Copper Project PEA Technical Report Reporting Post-Tax NPV8 of

~US$2.0 Billion and IRR of 22.5% is now Filed

March 31, 2026

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

filed the National Instrument 43-101 technical report (the “Technical Report”) with an effective date of

March 18, 2026 for the updated Preliminary Economic Assessment (“PEA” or “2026 PEA”) on its 100%-

owned Gunnison Copper Project located in the Cochise Mining District, Arizona, United States (the

“Project”). The Technical Report is available on SEDAR+ ( www.sedarplus.ca) under the Company’s issuer

profile and on the Company’s website. 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).

Per the Company’s press release dated February 25, 2026, the PEA outlines a large-scale, long-life copper

project utilizing open-pit mining and heap leach SXEW processing to produce copper cathode onsite for an

impactful contribution to refined copper supply in the United States. The Project has robust economics,

including an after-tax NPV8 of approximately US$2.0 billion, an internal rate of return of 22.5%, and a

payback period of 3.9 years at a base case copper price of $4.60/lb.

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 $1.70, Sustaining Cash Costs of $2.00, and All-In Sustaining Cash Costs of $2.05

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 Assumptions $4.60/lb Cu Consensus $5.75/lb Cu SPOT2

Net Present Value @ 8% (after-tax) $M 1,959 3,227

Internal Rate of return (after-tax) % 22.5% 31.8%

Payback Period # years 3.9 2.6

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

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

2

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

through creation of over 112,744 job years, $558 million in state and local county taxes, $1.43

billion in federal taxes, and $21.9 billion in total economic output, based on an Independent

Economic Impact Study conducted by the Eller Partnerships Office at the University of Arizona.

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.

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 1,959

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

Internal Rate of return (after-tax) % 22.5%

Payback Period # years 3.9

EBITDA1 (annual average Y1-Y15) $ millions 486

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 millions tons 641

Limestone Mined millions tons 133

Alluvium-Gravel waste millions tons 1,007

Hard-Rock waste millions tons 501

Copper Grade placed on Heap % CuT 0.43%

Average Annual Crusher Throughput (Max) millions tons 40

Recoveries % CuT 68%

Oxide / Enriched Recoveries % CuTSol 90.2%

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

Recovered Copper Cathode millions lbs 3,187

Average Annual Copper Production (years 1-15) millions lbs 174

Initial Capital (including contingency) $ millions 1,556

Initial Capital Excluding Acid Plant $ millions 1,273

Capital Intensity1 $/ton Cu Capacity 17,609

Capital Intensity Excluding Acid Plant $/ton Cu Capacity 14,411

Profitability Ratio $/ton Cu Capacity 1.26

Expansion Capital (including contingency) $ millions 682

Sustaining Capital2 $ millions 587

Cash Cost (C1)3 $/lb Cu 1.70

Sustaining Cash Cost4 $/lb Cu 2.00

All-In Sustaining Cash Cost5 $/lb Cu 2.05

3

1. Capital intensities are calculated as initial capital, divided by maximum annual copper cathode plant capacity of

88.3 Ktons. 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

2. 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

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

administrative costs ("G&A")

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

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

excludes expansion and initial capital, and income taxes

Table 3: Report Sensitivities to the Copper Price

Copper Price

Sensitivities Units $4.25/lb $4.60/lb $5.00/lb $5.50/lb $6.00/lb $6.50/lb $7.00/lb

NPV8 M$ 1,566 1,959 2,403 2,953 3,500 4,043 4,586

IRR % 19.55% 22.51% 25.81% 29.84% 33.73% 37.47% 41.12%

Project Payback years 5.2 3.9 3.3 2.8 2.5 2.2 2.0

LOM Cu Gross

Revenue M$ 13,364,882 14,484,547 15,764,165 17,363,687 18,963,209 20,562,731 22,162,253

LOM EBITDA M$ 13,520,441 14,588,504 15,808,666 17,333,310 18,857,478 20,381,280 21,904,794

FCF - Unlevered

(post-tax) M$ 9,031,003 9,867,503 10,818,120 12,005,261 13,192,045 14,378,553 15,564,846

Mineral Resource Estimate

The Gunnison Deposit Mineral Resources are classified in order of increasing geological and quantitative

confidence into Inferred, Indicated, and Measured categories in accordance with the “CIM Definition

Standards – For Mineral Resources and Mineral Reserves” and therefore Canadian National Instrument 43-

101.

Table 4: Combined Oxide, Transitional, and Sulfide Resources

Total Resources (Oxide + Transitional + Sulfide)

Resource Class

Short Tons

(millions)

Total Cu

(%)

Cu Pounds

(millions)

Measured 191.5 0.37 1,423

Indicated 654.5 0.31 3,768

Measured + Indicated 846.1 0.33 5,190

Inferred 94.0 0.21 397

Notes:

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

2. Mineral Resources are reported within an optimized pit at a 0.05% total copper cut-off for oxide and

transition material, and 0.1% cut-off for sulfide.

3. Rounding may result in apparent discrepancies between tons, grade, and contained metal content.

4. The Effective Date of the Mineral Resource estimate is January 23, 2026.

4

The Strong & Harris project resources are summarized in

Table Error! No text of specified style in document.-1.

Table Error! No text of specified style in document.-1: Strong & Harris Mineral Resources

(0.07% Cu cutoff)

Classification

Short

Tons

(millions)

% Cu %

CuOx % Zn oz Ag/

ton

Cu lbs

(millions)

CuOx lbs

(millions)

Zn lbs

(millions)

Ag oz

(millions)

Inferred 76.070 0.49 0.32 0.56 0.12 740.0 482.691 855.707 8.971

1. The Effective Date of the mineral resources is January 23, 2026.

2. The project mineral resources are shown in bold and are comprised of all model blocks at a 0.07%

Cu cutoff that lie within optimized resource pits.

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

4. The estimate of mineral resources may be materially affected by geology, environmental, permitting,

legal, title, taxation, sociopolitical, marketing, or other relevant issues.

5. Rounding as required by reporting guidelines may result in apparent discrepancies between tons,

grade, and contained metal content.

The estimate of mineral resources may be materially affected by geology, environmental, permitting, legal,

title, taxation, sociopolitical, marketing, or other relevant issues. Potential risk factors include changes in

metal prices, increases in operating costs, fluctuations in labor costs and availability, availability of

investment capital, infrastructure failures, changes in government regulations, community engagement and

socio-economic community relations, civil disobedience and protest, permitting and legal challenges, and

general environmental concerns. However, the author is not aware of any such factors that may materially

affect the Gunnison or Strong & Harris mineral resources as of the date of the Report. The impact of taxation

was taken into consideration when establishing cut-off grade.

The Mineral Resources presented herein are inclusive of the economic analysis presented in the report

which therefore represents a subset of the Mineral Resources under slightly different economic inputs, most

notably lower copper price.

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.

Financial Model – Key Inputs

2

Financial Model – Key Inputs

3

Financial Model – Cash Flows by Year

TECHNICAL REPORT AND QUALIFIED PERSONS

The Technical Report was prepared under the supervision of John Woodson, PE, SME-RM, of M3 Engineering

& Technology Corporation, Tucson, Arizona, who is a Qualified Person that is independent of the Company.

The Technical Report also received contributions from the following additional Qualified Persons, who are

also independent of the Company:

 Mr. John Woodson, of M3 Engineering & Technology Corporation, Tucson, Arizona (capital and

operating costs, and economic analysis).

 Mr. Jeffrey Bickel of RESPEC of Reno, Nevada (geology and mineral resource).

 Mr. Jacob Richey, of IMC of Tucson, Arizona (mining methods).

 Mr. Tom Ryan, of CNI of Tucson, Arizona (pit slope angles)

 Dr. Terence P. McNulty of T.P. McNulty & Associates of Tucson, Arizona (metallurgy).

 Dr. Abyl Sydykov of M3 Engineering & Technology Corporation, Tucson, Arizona (mineral recovery)

 Mr. R. Douglas Bartlett, of Clear Creek and Associates of Phoenix, Arizona (hydrology, mining

method, permitting and environment).

 Mr. Tyler Peck, of Burgex Mining Consultants, Sandy, Utah (Limestone and cement)

Each of these Qualified Persons has reviewed and approved the technical information contained in this

news release that is relevant to their area of responsibility and verified the data underlying such technical

information.

ABOUT GUNNISON COPPER

Gunnison Copper Corp. is a multi-asset pure-play copper developer and producer that controls the Cochise

Mining District (the district), containing 12 known deposits within an 8 km economic radius, in the Southern

Arizona Copper Belt.

Its flagship asset, the Gunnison Copper Project, has a Measured and Indicated Mineral Resource containing

over 846.1 million tons with a total copper grade of 0.33% (Measured Mineral Resource of 191.5 million tons

at 0.37% and Indicated Mineral Resource of 654.5 million tons at 0.31%), and a preliminary economic

assessment ("PEA") yielding robust economics including an NPV8% of $2 billion, IRR of 23%, and payback

period of 3.9 years. It is being developed as a conventional operation with open pit mining, heap leach, and

SX/EW refinery to produce finished copper cathode on-site with direct rail link.

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.

In addition, Gunnison's Johnson Camp Asset, which is now in production, is fully funded by Nuton LLC, a Rio

Tinto Venture, with a production capacity of up to 25 million lbs of finished copper cathode annually.

Other significant deposits controlled by Gunnison in the district, with potential to be economic satellite

feeder deposits for Gunnison Project infrastructure, include South Star, and eight other deposits.

For more information on the Company, please visit our website at www.GunnisonCopper.com.