Montero commences initial drilling at Elvira, Chile

Toronto, Ontario--(Newsfile Corp. - May 28, 2026) - Montero Mining and Exploration Ltd. (TSXV: MON) (OTC Pink: MXTRF) (FSE: ES0) (" Montero " or the " Company ") is pleased to announce that drilling has commenced at the Elvira Gold Project in Chile. The simplified geology and concession area are shown in Figure 1. Figure 1: Elvira Project concession boundary and simplified geology displayed on a topographic base image, illustrating the broader structural and lithological framework.

To view an enhanced version of this graphic, please visit: https://images.newsfilecorp.com/files/11789/299210_94327834d4e7dadb_001full.jpg The current first-pass drill program is designed to test the highest-priority integrated drill targets defined by Montero from its geological, geochemical, and geophysical review of the Elvira system. The initial phase of drilling is designed to test the strongest converging vectors from the upper gold-bearing epithermal system into the deeper porphyry Cu-Au domain. These vectors include surface geochemistry, deep chargeability, resistivity, structural interpretation, historical drilling, and project-scale alteration mapping derived from ASTER and Sentinel-2 imagery.

Initial drilling has commenced with MON-ELV-01, a priority hole designed to test the central part of the >22.5 mV/V chargeability anomaly at depth beneath the historical drillhole EL-12 area (Figures 2 to 5). This target was prioritised because it integrates several of the strongest vectors identified by Montero on the project; including proximity to surface gold anomalism, a strong chargeability anomaly at depth, coincident resistivity features, favourable deep structural setting, the historical gold intersection in EL-12 (Buena Vista Gold reported drillhole EL-12 intersected 4 m @ 4.9 g/t Au from 264-268 m, including 17.85 g/t Au, this is interpreted by Montero as a high-grade feeder/upflow position), and a broader alteration footprint interpreted from ASTER and Sentinel-2 imagery. Montero also considers the target to be supported by Fathom's modelling work, which indicates potential for a deeper porphyry system beneath Elvira.

The hole is intended to test the interpreted link between the shallow epithermal gold system, a possible feeder setting in the EL-12 area, and a deeper porphyry Cu-Au target. Dr. Tony Harwood, President and Chief Executive Officer of Montero, commented: "Montero's work at Elvira has materially improved our understanding and highlighted the scale of the mineral system. Drillhole MON-ELV-01 is designed to test a strong chargeability anomaly at depth beneath historical drill intercept, where Montero interprets a compelling epithermal feeder to porphyry Cu-Au target." The current first-pass drilling program is expected to comprise four initial holes for approximately 2,025 metres, subject to drilling conditions and operational progress.

Follow-up holes may be adjusted based on results from the initial phase. Following MON-ELV-01, the initial sequence is expected to test: The EL-09/ELRC-16/ELRC-22 area, where historical drilling supports a copper vector toward a deeper chargeability target. The epithermal cap-to-porphyry link target.