Dr. Stephen Twyerould reports

GUNNISON COPPER ANNOUNCES FIRST COPPER PRODUCTION FROM JOHNSON CAMP MINE

First production of pure copper cathode from Gunnison Copper Corp.'s fully operational Johnson Camp mine (JCM) in southeastern Arizona commenced in the last week of August, 2025, establishing Gunnison as the newest American copper producer.

Following the successful start-up of the solvent extraction (SX) and electrowinning (EW) circuit (announced Aug. 11, 2025), copper cathode is now officially in production from run-of-mine (ROM) ore. Gunnison has achieved this critical milestone ahead of schedule, producing made-in-America copper for domestic sales.

"This is an incredible moment for Gunnison and for U.S. copper supply. To bring Johnson Camp into production ahead of schedule and with an excellent health and safety record is an achievement we're extremely proud of," stated Dr. Stephen Twyerould, chief executive officer and president. "Even more exciting is that we are now producing 100-per-cent-American-made copper at a time when our nation needs it most. We extend our gratitude to our dedicated team, valued stakeholders and especially Nuton LLC, a Rio Tinto venture, whose critical support made this possible."

Nuton is a key strategic and financial partner to Gunnison, supporting the restart of copper production at JCM. With exclusive rights to deploy its proprietary leaching technologies, Nuton is enabling a more sustainable and economically viable path for copper recovery at JCM.

"We congratulate Gunnison Copper and its dedicated team on this important milestone and are proud to support the company's efforts in revitalizing mining in Arizona," added Adam Burley, Nuton's chief executive officer. "We look forward to first copper production using Nuton technologies later this year, unlocking copper through innovation and partnership."

Key highlights of the Johnson camp mine commissioning:

• First copper production achieved ahead of schedule, firmly establishing Gunnison as America's newest copper producer;
• Exceptional safety performance: commissioning of the ROM copper production circuit completed without incident, underscoring Gunnison's uncompromising commitment to health and safety excellence;
• Critical U.S. supply: new domestic production strengthens American energy independence, national defence and advanced manufacturing capabilities;
• Partnerships: fully financed and supported by Nuton, a Rio Tinto venture, and awarded $13.9-million (U.S.) in 48C tax credits from the Department of Energy (see Gunnison's press release dated Jan. 16, 2025, for additional details);
• Growth trajectory: ramp-up in progress toward the name plate plant capacity of 25 million pounds of finished copper cathode annually.

About Gunnison Copper Corp.

Gunnison Copper is a multiasset pure play copper developer and producer that controls the Cochise mining district, containing 12 known deposits within an eight-kilometre 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 million tonnes with a total copper grade of 0.31 per cent (measured mineral resource of 191.3 million tonnes at 0.37 per cent and indicated mineral resource of 640.2 million tonnes at 0.29 per cent), and a PEA (preliminary economic assessment) yielding robust economics including a net present value (discounted at 8 per cent) of $1.3-billion, an internal rate of return of 20.9 per cent and a payback period of 4.1 years. It is being developed as a conventional operation with open-pit mining, heap leach and an 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 financed by Nuton, a Rio Tinto venture, with a production capacity of up to 25 million pounds 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 Nov. 1, 2024, and available on SEDAR+.

Dr. Stephen Twyerould, fellow of AusIMM, president and chief executive officer of the company, is a qualified person as defined by National Instrument 43-101. Dr. Twyerould has reviewed and is responsible for the technical information contained in this news release.

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