Mr. Ernest Mast reports

DORE COPPER PROVIDES UPDATE ON ITS PROJECT ACTIVITIES

Dore Copper Mining Corp. has provided an update on its project activities located near Chibougamau, Que.

Exploration activities

During second quarter 2023, the Dore Copper geology team focused on data compilation and interpretation for the Gwillim and Jaculet projects. A drilling program of 1,557 metres was completed in July, 2023.

Gwillim

During fourth quarter 2022, Dore Copper completed two drill holes (KOD-22-04 and 05) totalling 1,342 metres at the KOD zone in the western part of the Gwillim property, which is under a 50/50 joint venture with Argonaut Gold through its wholly owned subsidiary Prodigy Gold with Dore Copper being the operator.

Dore Copper reported the results from the first hole on May 29, 2023. KOD-22-04 intersected 9.67 grams per tonne gold over 5.3 metres, including 19.46 g/t Au over 2.1 metres, starting at a vertical depth of approximately 580 metres, and 11.10 g/t Au over 3.0 metres, which after a new revised interpretation are interpreted as Zone C of the KOD mineralized structure.

Hole KOD-22-05, drilled on the same pad as KOD-22-04 and approximately 60 metres west-southwest of Zone C intersected in KOD-22-04, was determined to have been stopped short of Zone C by approximately 50 metres and was therefore extended in the July drilling program.

In July, 2023, Dore Copper completed three holes totalling 957 metres at Gwillim. Hole KOD-22-05 was extended by 90 metres to test Zone C and the other two holes (KOD-23-06 and 07) tested a geophysical anomaly (airborne VTEM survey conducted in January, 2023), immediately west of the projected down plunge of the near-surface high-grade gold mineralization of Zone C.

Hole KOD-22-05E intersected Zone C from 633 to 654 metres with several specks of gold observed at the beginning of Zone C and mineralization similar to KOD-22-04 Zone C. Hole KOD-23-06 intersected a 1.5-metre interval containing chalcopyrite and sphalerite in stringers. Hole KOD-23-07 intersected the Signal zone (approximately 250 metres north of the KOD Zone C) characterized by several metres of massive pyrite, pyrrhotite and trace chalcopyrite and KOD zones A, B and C.

Assays for the three holes are expected in September. The KOD mineralized system remains open along strike to the west and below 600 metres.

Jaculet

Dore Copper completed one drill hole of 600 metres in July, 2023, to test the potential down plunge extension of high-grade copper mineralization intersected in two surface historical holes from Chibougamau Jaculet Mines Ltd. in 1956. Historical holes V17 and V17A (wedge from V17 and located approximately 50 metres to the east) intersected Jaculet Zone 1 at a vertical depth of approximately 400 metres with 4.55 per cent copper 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 1.5 metres of mineralization, mainly chalcopyrite in centrimetric veins, at a downhole depth of 438 metres (Jaculet Zone 1), approximately 12 metres below the interpreted location of the historical intercepts in V17 and V17A. It is believed that the location of the historical holes is perhaps inaccurate and more to the east, in the area of the underground workings, indicating that the mineralization hit in hole JA-23-01 is at the periphery of the main ore shoot. Assays are pending for hole JA-23-01.

Corner Bay metallurgical testwork

During fourth quarter 2022, a spatially diverse composite sample from the Corner Bay core was prepared for additional ore sorting tests at Steinert's facility in Kentucky, United States, using an XRT sensor (X-ray transmission) and a laser sensor. The composite sample weighted 202 kilograms and graded 2.20 per cent Cu, and included an 18-per-cent external mining dilution from the hangingwall and footwall of the mineralized interval. The results, announced on April 18, 2023, showed a copper grade increase of 77 per cent (from 2.20 per cent to 3.93 per cent) and copper recoveries in the order of 93.5 per cent with the final reject portion representing 47.5 per cent of the feed mass at a grade of 0.30 per cent Cu. Results were equally positive for gold, silver and molybdenum. Lastly, the arsenic grade of the two preconcentrates was found to be 12 parts per million, which leads to a final concentrate with low arsenic levels.

During second quarter 2023, a metallurgical test program was started at Base Metallurgical Laboratories in British Columbia. A total of four spatially diverse composites were prepared, including the samples from the Steinert ore sorting tests. The metallurgical testwork will include grind size optimization, reagent determination and grade recovery curves for copper. Recoveries for gold, silver and molybdenum will also be determined, as well as minor element concentrations in the copper concentrate. The program will also include thickening and filtration testing.

Preliminary results of the metallurgical testwork indicate high rougher recoveries of positive 95 per cent copper with little sensitivity to a grind size between 100 and 180 microns. Complete results are expected in third quarter 2023.

Environmental and social assessment

In June, 2023, Dore Copper received the project directive for the environmental and social assessment of its proposed hub-and-spoke operation from the Quebec Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks (MELCCFP). The project directive is for the development of two underground mines (Corner Bay and Devlin), the rehabilitation of the Copper Rand mill and the use of the existing tailings management facility.

Activities at Copper Rand mill

During 2022, obsolete electrical cables from the Copper Rand mill were removed as part of the refurbishment program. During second quarter 2023, the cables were stripped of their aluminum and rubber sheathing, and the copper was sold as No. 1 copper scrap.

The corporation project sites and infrastructures were not impacted by the forest fires in Northern Quebec. All fires in the Chibougamau area are currently under control. Dore Copper sincerely thanks all involved in mitigating the impacts of the forest fires in Northern Quebec and keeping employees and local communities safe.

Drilling and 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 ICP analysis were done at ALS in Vancouver, B.C. Samples were weighed, dried and 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 (50 grams) and sodium peroxide fusion ICP-MS finish for 34 elements. Samples assaying greater than 10.0 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 microm and analyzed by 50-gram fire assay with gravimetric finish.

Quality assurance/quality control 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, 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 aims to be the next copper producer in Quebec with an initial production target of 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 (1). The corporation has 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 (2). 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.

Please note: As of Aug. 1, the new address for the corporate office is 130 King St. West, Suite 1900, Toronto, Ont., M5X 1E3.

(1) Technical report titled "Preliminary Economic Assessment for the Chibougamau Hub-and-Spoke Complex, Quebec, Canada," dated June 15, 2022, in accordance with National Instrument 43-101 (Standards of Disclosure for Mineral Projects). The technical report was prepared by BBA Inc. with several consulting firms contributing to sections of the study, including SLR Consulting (Canada) Ltd., SRK Consulting (Canada) Inc. and WSP Inc.

(2) Sources for historic production figures: Economic Geology, v. 107, pp. 963-989 -- Structural and Stratigraphic Controls on Magmatic, Volcanogenic and Shear Zone-Hosted Mineralization in the Chapais-Chibougamau Mining Camp, Northeastern Abitibi, Canada, by Francois Leclerc et al. (Lac Dore/Chibougamau mining camp) and National Instrument 43-101 Technical Report on the Joe Mann Property dated Jan. 11, 2016, by Geologica Groupe-Conseil Inc. for Jessie Ressources Inc. (Joe Mann mine).

We seek Safe Harbor.