McEwen files NI 43-101 report on Tartan Mine

TORONTO, May 04, 2026 (GLOBE NEWSWIRE) -- McEwen Inc. (NYSE/TSX: MUX) (“McEwen” or the “Company”) is pleased to announce that it has filed on SEDAR+ an independent technical report prepared in accordance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects (“NI 43-101”) for the Tartan Mine Project, located near Flin Flon, Manitoba. The report, titled “Mineral Resource Estimate NI 43-101 Technical Report Tartan Mine Project, Manitoba, Canada” (the “Technical Report”), has an effective date of December 31, 2025. The Technical Report supports the mineral resource estimate for the Tartan Mine Project previously announced on March 23, 2026 , consisting of Indicated Resources of 2,619,000 tonnes at 3.67 g/t Au for 308,900 ounces of gold , and Inferred Resources of 2,832,900 tonnes at 3.32 g/t Au for 302,700 ounces of gold.

The Technical Report is available under the Company’s issuer profile on SEDAR+ at www.sedarplus.ca and on the Company’s website at https://www.mcewenmining.com/files/technical_reports/Manitoba/NI43-101TartanTR.pdf . Qualified Persons and Technical Information The Technical Report was prepared by Global Resource Engineering (GRE) based in Golden, Colorado, USA. The Qualified Persons for the report are Terre Lane, MMSA, Hamid Samari, MMSA, Dr. Todd Harvey, SME and Larry Breckenridge, P.E. all of whom work for GRE.

All are Qualified Persons as defined by SEC S-K 1300 and NI 43-101. As part of the preparation of the Tartan Mine Technical Report, GRE conducted a site visit in October 2025 to verify the data underlying the technical information. This data verification included an independent review of drill logs and logging checks, comparing the database entries against original assay certificates for the drill holes and examining QA/QC protocols and results from the submission of blank and certified reference materials.

Additionally, in-field checks of the geological mapping and existing drillhole collars took place and samples of selected intervals for check assays were completed. The reviewed data was verified to be in accordance with industry standards, did not identify any material issues and was found to be reliable and of suitable quality for use in the resource estimate and Technical Report. The scientific and technical information contained in this news release has been reviewed and approved by Luke Willis, P.Geo., McEwen’s Director of Resource Modelling, a Qualified Person as defined by NI 43-101.

ABOUT MCEWEN McEwen Inc. (listed on the NYSE and TSX under the symbol MUX ) is a growing gold and silver producer with operations and development projects in Canada, the U.S., Mexico and Argentina , and holds a 46.3% interest in McEwen Copper , owner of the large, world-class Los Azules copper project in Argentina. McEwen offers investors a compelling portfolio of hard money and critical minerals assets, combining current gold and silver production with massive copper optionality and exploration upside . CAUTION CONCERNING FORWARD-LOOKING STATEMENTS This news release contains certain forward-looking statements and information, including "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995.

The forward-looking statements and information expressed, are as at the date of this news release and are McEwen Inc.'s (the "Company") estimates, forecasts, projections, expectations or beliefs as to future events and results. Forward-looking statements and information are necessarily based upon a number of estimates and assumptions that, while considered reasonable by management, are inherently subject to significant business, economic and competitive uncertainties, risks and contingencies, and there can be no assurance that such statements and information will prove to be accurate. Therefore, actual results and future events could differ materially from those anticipated in such statements and information.

Risks and uncertainties that could cause results or future events to differ materially from current expectations expressed or implied by the forward-looking statements and information include, but are not limited to, fluctuations in the market price of precious metals, mining industry risks, political, economic, social and security risks associated with foreign operations, the ability of the Company to receive or receive in a timely manner permits or other approvals required in connection with operations, risks associated with the construction of mining operations and commencement of production and the projected costs thereof, risks related to litigation, the state of the capital markets, environmental risks and hazards, uncertainty as to calculation of mineral resources and reserves, foreign exchange volatility, foreign exchange controls, foreign currency risk, and other risks. Readers should not place undue reliance on forward-looking statements or information included herein, which speak only as of the date hereof. The Company undertakes no obligation to reissue or update forward-looking statements or information as a result of new information or events after the date hereof except as may be required by law.

See McEwen Inc.'s Annual Report on Form 10-K for the fiscal year ended December 31, 2025, and other filings with the Securities and Exchange Commission, under the caption "Risk Factors", for additional information on risks, uncertainties and other factors relating to the forward-looking statements and information regarding the Company. All forward-looking statements and information made in this news release are qualified by this cautionary statement. The NYSE and TSX have not reviewed and do not accept responsibility for the adequacy or accuracy of the contents of this news release, which has been prepared by the management of McEwen.

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