Montero Comments on Proposed Changes to Chile's Mining Concession Regime

Toronto, Ontario--(Newsfile Corp. - May 21, 2026) - Montero Mining and Exploration Ltd. (TSXV: MON) (OTC Pink: MXTRF) (FSE: ES0) (" Montero " or the " Company ") notes the announcement by the Government of Chile regarding proposed amendments to Chile's Mining Code and mining concession fee regime, aimed at supporting mineral exploration and development activities in the country. On May 18, 2026, the Government of Chile submitted a bill to Congress proposing amendments to the current mining concession fee framework established under Laws No. 21.420 and 21.649. The proposal includes measures intended to simplify and broaden access to reduced mining concession fees, particularly for exploration and development-stage projects.

The proposed reforms include: Elimination of the progressive escalation in exploitation concession fees currently applied to concessions not qualifying for reduced rates. Introduction of a reduced concession fee category linked to active exploration activities. Expansion of eligibility criteria for reduced concession fees.

Recognition of lawful operators, lessees and usufructuaries as eligible beneficiaries. Simplification of qualification requirements currently applicable under Article 142 ter of the Chilean Mining Code. The proposed legislation also seeks to recognise a broader range of activities as qualifying mining work, including exploration, permitting, environmental review, geological reporting and project development activities.

Dr. Tony Harwood, President and CEO of Montero, commented: "The proposed reforms represent an encouraging development for mineral exploration and project advancement in Chile. Junior exploration companies have faced increasing pressure from rising concession holding costs introduced under the recent mining patent reforms. The proposed changes appear intended to better align concession costs with the timelines and economic realities of mineral exploration and project advancement.

The Maricunga Belt is recognised as one of the world's premier gold and copper districts, and regulatory frameworks that support responsible exploration investment are important for maintaining Chile's attractiveness as a global mining jurisdiction." Montero is currently advancing its Elvira gold project in Chile's Maricunga Belt, where the Company recently commenced mobilisation activities and operational preparations for its Phase 1 diamond drilling program. The proposed legislative amendments remain subject to debate and approval by the Chilean National Congress before becoming law. About Montero Montero Mining and Exploration Ltd. is a Canadian exploration company focused on gold and copper exploration in Chile.

Montero holds a 100% interest in the Avispa copper-molybdenum project in the Palaeocene Porphyry Cu-Mo Belt of northern Chile and has an option to acquire the Elvira and Potrero gold projects in the Maricunga Gold Belt. These projects are being advanced through ongoing exploration activities. Montero is listed on the TSX Venture Exchange under the symbol MON and has 8,453,833 Common Shares and 735,383 stock options outstanding.

For more information, contact: Montero Mining and Exploration Ltd. Dr. Tony Harwood , President, and Chief Executive Officer E-mail: ir@monteromining.com Tel: +1 604 428 7050 www.monteromining.com Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION: This news release includes certain "forward-looking information" within the meaning of applicable Canadian securities laws. Forward-looking information in this press release includes, but is not limited to, statements regarding: the integration and interpretation of geological, geochemical and geophysical data; the application of artificial intelligence and machine learning tools; the identification, evaluation or prioritization of areas for further exploration; the potential for mineralization; and the timing or scope of future exploration activities, including any potential drilling.

Generally, forward-looking information can be identified by the use of forward-looking terminology such as "plans", "expects", "does not expect", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates", "does not anticipate", or "believes", or variations of such words and phrases, or statements that certain actions, events or results "may", "could", "would", "might" or "will" occur or be achieved. Such information is based on information currently available to Montero and on assumptions management believes are reasonable as of the date of this news release. Forward-looking information is subject to known and unknown risks, uncertainties and other factors that may cause actual results, level of activity, performance or achievements of the Company to be materially different from those expressed or implied by such forward-looking information.

These risks and uncertainties include, but are not limited to: risks related to mineral exploration and development activities; uncertainties inherent in the interpretation of geological and geophysical data; the speculative nature of mineral exploration; commodity price fluctuations; changes in general market conditions; regulatory approvals and permitting risks; availability of financing; operational and technical risks; and other risk factors described in the Company's public disclosure documents filed on SEDAR+. There can be no assurance that such forward-looking information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Readers are cautioned not to place undue reliance on forward-looking information.

Montero does not undertake to update any forward-looking information, except in accordance with applicable securities laws. To view the source version of this press release, please visit https://www.newsfilecorp.com/release/298386 Source: Montero Mining and Exploration Ltd.