Harfang Exploration Inc. (TSX-V: HAR) reports assay results from 2026 diamond drilling at the Mista target at its wholly-owned Serpent Project in Eeyou Istchee James Bay, Québec (see Figure 1).

HIGHLIGHTS

• The drill program was designed to test the Mista target, a 650-metre-long trend defined by coincident surface mineralization, a moderate magnetic survey, and a strong chargeability anomaly.
• Results are highlighted by: 0.47% Cu, 0.22 g/t Au and 6.76 g/t Ag over 4.30 m, 0.17% Cu, 0.25 g/t Au, and 2.10 g/t Ag over 6.10 m (incl. 0.68% Cu, 1.26 g/t Au and 8.84 g/t Ag over 1.15 m), and 0.39% Cu, 0.19 g/t Au, 12.1 g/t Ag, 0.49% Zn, and 0.21% Pb over 4.05 m.
• Geological observations and drill results have identified a broad metal zonation pattern including both Cu-Au-Ag mineralization, and Zn-Cu-Pb-Ag-Au mineralization in the surrounding sedimentary rock, consistent with intrusion-related hydrothermal systems.

Rick Breger, President and CEO of Harfang, commented: “Although this drill program did not replicate the widths and grades observed at surface, it successfully confirmed the presence of a mineralized hydrothermal system at Mista. The identification of a clear metal zonation pattern, including copper-gold-silver and polymetallic mineralization along a 650-metre trend, provides strong support for our geological model and demonstrates the scale of the system. We believe Mista remains an attractive exploration target and the results provide valuable information for future exploration.”

Drill Program

Drilling was designed to test Mista, a high-priority target located within the 50,000-hectare Serpent Project (see Figure 2). Mista is a Cu-Au-Ag target that the Company discovered during 2019 summer prospecting, followed up with DC-IP in 2020, and additional surface exploration in 2024. Previous exploration at Mista identified surface mineralization in outcrops along a 350-metre strike length, including channel samples returning 1.0% Cu, 0.2 g/t Au and 7.9 g/t Ag over 12.9 metres. Additionally, the results from the DC-IP survey indicated a strong chargeability anomaly suggesting potential mineralization spanning more than 650 metres along strike. From mid-March to early April 2026, a total of 1,188 metres were completed in six diamond drill holes (see Table 1 & Figure 3).

Mineralization consists of pyrite ranging from disseminated to vein-type, chalcopyrite ± molybdenite ± sphalerite within silica- and sericite-altered fine-grained quartz arenites and wackes proximal to contacts with granodiorite (see Figure 4). The alteration pattern coincides with the surface observations.

Assay results from the program outline metal zonation along a northwest to southeast trend. In the northwestern part of the trend, SER-26-001 returned 0.51% Mo over 0.75 metres. In the central zone, results are highlighted by 0.47% Cu, 0.22 g/t Au and 6.76 g/t Ag over 4.30 metres in SER-26-006, as well as 0.17% Cu, 0.25 g/t Au and 2.10 g/t Ag over 6.10 metres (incl. 0.68% Cu, 1.26 g/t Au and 8.84 g/t Ag over 1.15 metres) in SER-26-002. In the southeastern part, results are highlighted by 0.39% Cu, 0.19 g/t Au, 12.14 g/t Ag, 0.49% Zn and 0.21% Pb over 4.05 metres in SER-26-003 (see Table 2 & Figure 3).

The strongest IP chargeability anomaly, tested by the first drill hole of the program in the northwestern part of the trend, corresponds primarily to a magnetite- and sulphide-altered granodiorite. The overall sulphide content in this altered intrusion is low.

Table 1: DDH Location Information

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Note: Coordinates are in NAD83 UTM Zone 18.

Table 2: Significant Intervals

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Note: Assays are not capped and all lengths are reported as core lengths (true widths have not been determined).

Geological Model and Discussion

Observations and assay results suggest a broad metal zonation pattern centred on the felsic intrusive system. Molybdenum is preferentially associated with the altered granodiorite intersected in SER-26-001. Copper-gold-silver mineralization occurs in proximal metasomatized clastic sedimentary rocks near granodiorite contacts, particularly in SER-26-002 and SER-26-006. Farther from the interpreted intrusive centre and along trend, SER-26-003 returned a distal polymetallic signature characterized by zinc, copper, lead, silver, and gold mineralization. This zonation supports the Company’s interpretation of an intrusion-related hydrothermal system.

The drill results also suggest that the hydrothermal system extends at depth. However, drill intercepts returned lower grades and narrower mineralized zones than observed at surface, typically ranging from 1 to 6 metres in core length compared with zones exceeding 10 metres in surface trenches.

Drilling, Core Sampling Protocols, and Quality Control

The drilling program was carried out by Forage Val-d’Or using NQ-diameter diamond-tipped drill bits. Drill core was transported daily from the drill site to the core logging facility. Under the supervision of Harfang geologists, core was systematically logged, photographed, and split in half using a core splitter. One half of the core was retained on site for reference, while the other half was sampled at regular intervals based on geological observations.

All samples were securely bagged and transported to AGAT Laboratories in Val-d’Or. Gold was analysed by atomic absorption spectrometry following fire assay on a 50-gram split. Copper, silver, zinc, lead, and molybdenum were analysed using a four-acid digestion with ICP-OES/MS finish for a 50-element suite. Sample preparation and analytical procedures were carried out at AGAT facilities that are ISO/IEC 17025 accredited. A strict QA/QC protocol was implemented, with certified reference materials, blank samples, and field duplicates inserted into the sample stream at regular intervals. QA/QC results were reviewed and validated by the qualified person.

Qualified Person

Ludovic Bigot, P.Geo., VP Exploration of Harfang, prepared and approved the technical information contained in this news release. Mr. Bigot is a qualified person within the meaning of National Instrument 43-101 on standards of disclosure for mineral projects.

Figure 1. Regional map showing the location of Serpent and other Harfang assets.

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Figure 2. Location map of the Serpent Project and the Mista target.

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Figure 3. Plan view map of Mista showing the 2026 drillholes locations and significant intervals at Mista.

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Figure 4. Photo of mineralized core from SER-26-003.

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