96% of Analyzed Limestone Meets Industrial Specifications for Several Saleable Products, Unlocking Value for Updated PEA Expected in Q1 2026

Gunnison Copper Corp. (TSX: GCU) (OTCQB: GCUMF) (FSE: 3XS0) 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 15^th, 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).

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 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 sampling, recovery or other factors that could materially affect the accuracy or reliability of the data referred to in this news release.