Gunnison Copper Reports Positive Results from Limestone Evaluation to Add New By- Product Revenue at the Gunnison Project in Southeast Arizona 96% of Analyzed Limestone Meets Industrial Specifications for Several Saleable Products,
NEWS RELEASE
Gunnison Copper Reports Positive Results from Limestone Evaluation to Add New By-
Product Revenue at the Gunnison Project in Southeast Arizona
96% of Analyzed Limestone Meets Industrial Specifications for Several Saleable Products,
Unlocking Value for Updated PEA Expected in Q1 2026
October 23, 2025
Gunnison Copper Corp. (TSX: GCU) (OTCQB: GCUMF) (FSE: 3XS0) (“Gunnison” or the
“Company”) is pleased to report positive results from its ongoing High-Value-Add Work Program
evaluating the commercial potential of limestone occurring within the planned Gunnison Open Pit mine
plan in southeast Arizona. The evaluation indicates that a substantial portion of the limestone, material
that is currently scheduled as waste in the mine plan, is suitable for a range of industrial end-use markets,
including cement, agricultural lime, and premium paper filler/paint and coatings.
"These initial results suggest a significant opportunity to unlock value from material previously
categorized as waste, with potential to supply cement, agricultural lime, and premium filler markets,” said
Roland Goodgame, SVP Business Development. “As part of our High-Value-Add Work Program, this
limestone evaluation could enhance project economics by diversifying revenue and reducing waste
handling, and we intend to integrate these findings into our updated PEA expected in Q1 2026, with PFS
work already underway.”
Limestone Evaluation Highlights:
Sampling Basis: Historical drill holes NSD-40, NSD-41, and NSD-43 were reviewed. Whole-rock
analysis (XRF and ICP-MS) was completed on 883 feet of limestone core, representing ~39% of
the total logged limestone in these holes.
Industrial Suitability: Approximately 96% of the analyzed material met indicative thresholds for
cement and agricultural lime applications, averaging >96% calcite and >55% CaO.
Premium Applications: Approximately 21% of the analyzed material met indicative thresholds for
premium paper filler/coating and high-brightness paint/coatings applications, averaging >97%
calcite and ~56% CaO.
Scale of Opportunity: The current mine plan schedules approximately 224 million tons of
limestone as waste over the contemplated 16-year mine life. Based on the representativeness
of these intersections and visual similarity of non-assayed intervals, the Company believes the
proportion of commercially suitable material could increase following further analysis.
Context and Methodology:
The limestone evaluation forms one pillar of Gunnison’s broader High-Value-Add Work
Program, which also includes mineral sorting (See initial results announced September 15th,
2025), metallurgical optimization, and mine plan refinements intended to improve recoveries,
lower operating costs, and enhance head grades.
Whole-rock (XRF/ICP-MS) data were used to approximate industrial suitability; final product
qualification for specific end-uses will require additional specification-driven testing (e.g.,
brightness/whiteness, abrasiveness, particle size distribution, deleterious elements, and pilot-
scale processing where applicable).
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Next Steps:
Expand sampling coverage beyond the initial 883 feet to improve statistical confidence across
the planned open pit area.
Conduct specification-based test work (e.g., brightness/whiteness indices, deleterious
screening, grindability) aligned to cement, ag-lime, and premium filler/paint product standards.
Advance mine plan and materials-handling trade-offs (selective mining, in-pit stockpiling, on-site
sizing) to define practical pathways to market.
Evaluate logistics, permitting, and commercialization options, including potential marketing
partnerships and offtake discussions, for incorporation into the updated PEA (Q1 2026) and the
PFS scope.
All drill holes have been drilled using diamond drill rigs to generate HQ sized core. Whole core was sent
to independent laboratory ALS Global in Reno, Nevada for Wholerock analysis including major, minor
and trace elements. Pulps and sample rejects are stored by Gunnison for future reference.
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 831.6 million tons with a total copper grade of 0.31% (Measured Mineral Resource of
191.3 million tons at 0.37% and Indicated Mineral Resource of 640.2 million tons at 0.29%), and a
preliminary economic assessment (“PEA”) yielding robust economics including an NPV8% of $1.3Billion,
IRR of 20.9%, and payback period of 4.1 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 Strong and Harris, South Star, and eight other
deposits.
For additional information on the Gunnison Project, including the PEA and mineral resource estimate,
please refer to the Company’s technical report entitled “Gunnison Project NI 43-101 Technical Report
Preliminary Economic Assessment” dated effective November 1, 2024 and available on SEDAR+ at
www.sedarplus.ca.
Roland Goodgame, Senior Vice President Business Development of the Company is a Qualified Person
as defined by NI 43-101. Dr. Goodgame has reviewed and is responsible for the technical information
contained in this news release.
Dr. Goodgame has verified the data disclosed in this news release, including the assay and test data
underlying the information or opinions contained in this news release. Dr. Goodgame verified the data
disclosed in this news release by reviewing imported and sorted assay data; checking the performance
of blank samples and certified reference materials; and reviewing grade calculation formulas. Dr.
Goodgame detected no significant QA/QC issues during review of the data and is not aware of any
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sampling, recovery or other factors that could materially affect the accuracy or reliability of the data
referred to in this news release.
For more information on Gunnison, please visit our website at www.GunnisonCopper.com
For further information regarding this press release, please contact:
Gunnison Copper Corp.
Concord Place, Suite 300, 2999 North 44th Street, Phoenix, AZ, 85018
Melissa Mackie
T: 647.533.4536
www.GunnisonCopper.com
Cautionary Note Regarding Forward-Looking Information
This news release contains "forward-looking information" concerning anticipated developments and events that may
occur in the future. Forward looking information contained in this news release includes, but is not limited to,
statements with respect to: (i) the intention to deploy the Nuton® technology at the Johnson Camp mine and future
production therefrom; (ii) the continued funding of the stage 2 work program by Nuton; (iii) the details and expected
results of the stage two work program; (iv) timelines for future production and production capacity from the
Company’s mineral projects; (v) that a substantial portion of the limestone, material that is currently scheduled as
waste in the mine plan, is suitable for a range of industrial end-use markets; (vi) that there is a significant opportunity
to unlock value from material previously categorized as waste; (vii) enhancement of project economics by
diversifying revenue and reducing waste handling; (viii) that the Company believes the proportion of commercially
suitable material could increase(ix) plans for an update to the preliminary economic assessment and planned pre-
feasibility study; (x) the results of the preliminary economic assessment on the Gunnison Project; and (xi) the
exploration and development of the Company’s mineral projects.
In certain cases, forward-looking information can be identified by the use of words such as "plans", "expects" or
"does not expect", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate",
or "believes", or variations of such words and phrases or state that certain actions, events or results "may", "could",
"would", "might", "occur" or "be achieved" suggesting future outcomes, or other expectations, beliefs, plans,
objectives, assumptions, intentions or statements about future events or performance. Forward-looking information
contained in this news release is based on certain factors and assumptions regarding, among other things, Nuton
will continue to fund the stage 2 work program, the availability of financing to continue as a going concern and
implement the Company’s operational plans, the estimation of mineral resources, the realization of resource
estimates, copper and other metal prices, the timing and amount of future development expenditures, the estimation
of initial and sustaining capital requirements, the estimation of labour and operating costs (including the price of
acid), the availability of labour, material and acid supply, receipt of and compliance with necessary regulatory
approvals and permits, the estimation of insurance coverage, and assumptions with respect to currency fluctuations,
environmental risks, title disputes or claims, and other similar matters. While the Company considers these
assumptions to be reasonable based on information currently available to it, they may prove to be incorrect.
Forward looking information involves known and unknown risks, uncertainties and other factors which may cause
the actual results, performance or achievements of the Company to be materially different from any future results,
performance or achievements expressed or implied by the forward-looking information. Such factors include risks
related to the Company not obtaining adequate financing to continue operations, Nuton failing to continue to fund
the stage 2 work program, the breach of debt covenants, risks inherent in the construction and operation of mineral
deposits, including risks relating to changes in project parameters as plans continue to be redefined including the
possibility that mining operations may not be sustained at the Gunnison Copper Project, risks related to the delay
in approval of work plans, variations in mineral resources and reserves, grade or recovery rates, risks relating to
the ability to access infrastructure, risks relating to changes in copper and other commodity prices and the worldwide
demand for and supply of copper and related products, risks related to increased competition in the market for
copper and related products, risks related to current global financial conditions, risks related to current global
financial conditions on the Company’s business, uncertainties inherent in the estimation of mineral resources,
access and supply risks, risks related to the ability to access acid supply on commercially reasonable terms, reliance
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on key personnel, operational risks inherent in the conduct of mining activities, including the risk of accidents, labour
disputes, increases in capital and operating costs and the risk of delays or increased costs that might be
encountered during the construction or mining process, regulatory risks including the risk that permits may not be
obtained in a timely fashion or at all, financing, capitalization and liquidity risks, risks related to disputes concerning
property titles and interests, environmental risks and the additional risks identified in the “Risk Factors” section of
the Company’s reports and filings with applicable Canadian securities regulators.
Although the Company has attempted to identify important factors that could cause actual actions, events or results
to differ materially from those described in forward-looking information, there may be other factors that cause
actions, events or results not to be as anticipated, estimated or intended. Accordingly, readers should not place
undue reliance on forward-looking information. The forward-looking information is made as of the date of this news
release. Except as required by applicable securities laws, the Company does not undertake any obligation to
publicly update or revise any forward-looking information.