Mr. Ernest Mast reports

DORE COPPER REPORTS EXPLORATION DRILL RESULTS - INTERSECTS SHALLOW MINERALIZATION GRADING 4.4 G/T AU OVER 9.8 METRES AT GWILLIM

Dore Copper Mining Corp. has released results from its drilling campaign of 1,557 metres completed in July, 2023, at the Gwillim and Jaculet projects, both located near Chibougamau, Que.

Ernest Mast, president and chief executive officer of Dore Copper, commented: "Our summer drilling program at Gwillim has shown the potential of the Signal zone, another high-grade mineralized zone to the north of the KOD zones. The geological model for Gwillim continues to advance and further work is warranted to test the potential of these high-grade zones and to identify additional gold mineralized structures."

Gwillim

In July, 2023, Dore Copper completed three holes totalling 957 metres at Gwillim. Hole KOD-22-05 was extended by 90 metres to test KOD zone C and the other two holes (KOD-23-06 and 07) tested a geophysical anomaly (airborne VTEM )versatile time-domain electromagnetic) survey conducted in January, 2023), located immediately west of the KOD zone (refer to Aug. 1, 2023, news release).

Hole KOD-22-05E intersected KOD zone C from 633 to 654 metres with anomalous gold values in several decimetric zones containing variable amounts of pyrite, pyrrhotite and chalcopyrite.

Hole KOD-23-06 intersected a 1.7-metre interval (interpreted as KOD zone A) containing stringers of chalcopyrite and sphalerite with a highly chloritized basalt. No significant gold mineralization was reported.

Hole KOD-23-07 intersected the Signal zone at a downhole depth of 15.5 metres with an intercept of 4.4 grams per tonne Au over 9.8 metres, including 16.51 g/t Au over 2.3 metres, characterized by decimetric bands of massive pyrrhotite, pyrite and traces chalcopyrite. Results from a downhole geophysical survey completed in the hole shows an off-hole anomaly located approximately 100 metres down and west of this gold intercept. The KOD zone envelope (zones A, B1, B2 and C) was intersected from 358.5 to 462.3 metres, characterized by several intervals containing pyrite, pyrrhotite and chalcopyrite within the pillow rims (typical of the KOD zone). No significant gold mineralization was reported.

The Signal zone has been historically traced over a strike length of 600 metres and is approximately 200 metres north of the KOD zone C. In the late 1980s, approximately 2,357 metres in 27 holes tested the Signal zone. In addition, a number of historical holes were drilled from underground intercepting both the Signal and KOD zones. The best historical gold intersections from the surface program included: 7.1 g/t Au over 2.6 metres (SZ-87-6), 34.96 g/t Au over 1.37 metres (SZ-87-10) and 22.9 g/t Au over 1.2 metres (GL-41). Dore Copper hole KOD-21-02 had also intersected the Signal zone with 3.33 g/t Au over 13.3 metres at a downhole depth of 28 metres. A compilation of this historical work is currently under way.

The KOD mineralized system remains open along strike to the east and below 600 metres. The Signal zone for its part remains open below 230 metres.

The Gwillim property is under a 50/50 joint venture with Argonaut Gold through its wholly owned subsidiary Prodigy Gold with Dore Copper being the operator.

Jaculet

Dore Copper completed one drill hole of 600 metres in July, 2023, which tested the strike extension of Jaculet zone 1, approximately 100 metres to the west of a previously mined out area and two high-grade copper intercepts in two historical holes, at a vertical depth of approximately 400 metres. The two surface historical holes from Chibougamau Jaculet Mines Ltd. in 1956 had intersected with 4.55 per cent Cu and 0.86 g/t Au over 6.7 metres and 4.25 per cent Cu and 0.59 g/t Au over 6.4 metres, respectively (refer to May 3, 2023, news release).

Hole JA-23-01 intersected 2.29 per cent Cu and 0.36 g/t Au over 1.5 metres, mainly chalcopyrite in centrimetric veins at a downhole depth of 438 metres (Jaculet zone 1). It is now interpreted that the mineralization in hole JA-23-01 is at the periphery of the main Jaculet zone 1 ore shoot. The deposit remains open below 400 metres.

Drilling and quality assurance/quality control

The company is using Miikan Drilling as the drilling contractor. Miikan is a joint venture between Chibougamau Diamond Drilling Ltd., the first nations community of Ouje-Bougoumou and the first nations community of Mistissini, both located in the Eeyou Istchee territory.

Sample (half core) preparation was done at ALS Canada Ltd. in Val d'Or, Que., and the fire assay and inductively coupled plasma analysis was done at ALS in Vancouver, B.C. Samples were weighed, dried, crushed to 75 per cent passing two millimetres, split to 250 grams and pulverized to 85 per cent passing 75 microns. Samples are fire assayed for gold (Au) (50 grams) and sodium peroxide fusion inductively coupled plasma mass spectrometry finish for 34 elements. Samples assaying greater than 10 g/t Au are reanalyzed with a gravimetric finish using a 50-gram charge. If visible gold is observed in the sample, the assay is performed by metallic screening whereby the entire sample is crushed, a one-kilogram portion is pulverized and screened to 106 micrometres, and analyzed by 50-gram fire assay with gravimetric finish.

QA/QC is done in-house by Dore Copper geologists with oversight from the vice-president, exploration. The check samples (blanks and standards -- 4 per cent of total samples with another 2 per cent of core duplicates taken on half split core) that were inserted into the sample batches are verified against their certified values and are deemed a pass if they are within three standard deviations of the certified value. The duplicates are evaluated against each other to determine mineralization distribution (nugget). If there are large discrepancies in the check samples, then the entire batch is requested to be reassayed.

Sylvain Lepine, MSc, PGeo, MBA, vice-president, exploration, of the corporation and a qualified person within the meaning of National Instrument 43-101, has reviewed and approved the technical information contained in this news release.

About Dore Copper Mining Corp.

Dore Copper Mining aims to be the next copper producer in Quebec with an initial production target of over 50 million pounds of copper equivalent annually by implementing a hub-and-spoke operation model with multiple high-grade copper-gold assets feeding its centralized Copper Rand mill. The corporation delivered its preliminary economic assessment in May, 2022, and is proceeding with a feasibility study.

The corporation has consolidated a large land package in the prolific Lac Dore/Chibougamau and Joe Mann mining camps that has historically produced 1.6 billion pounds of copper and 4.4 million ounces of gold. The land package includes 13 former-producing mines, deposits and resource target areas within a 60-kilometre radius of the corporation's Copper Rand mill.

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