Doré Copper Mining Corp. (TSX-V: DCMC) (OTCQX: DRCMF) (FRA: DCM) wishes to correct an error in reporting the gold assay in hole LDR-22-01W2 announced on March 2, 2023. The March 2, 2023 news release reported an interval of 3.98% Cu and 0.36 g/t Au over 2.35 meters, including 16.45% Cu and 0.7 g/t Au over 0.35 meter which was in error for the gold assay. The actual interval was:

• LDR-22-01W2: 3.98% Cu, 3.59 g/t Au and 11.7 g/t Ag over 2.35 meters, including 16.45% Cu and 7.13 g/t Au, and 31.0 g/t Ag over 0.35 meter (Table 1 and Figure 1)

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 preparation was done at SGS Canada Inc. in Val-d’Or, Québec and Burnaby, B.C. and fire assay and ICP analysis was done at SGS in Burnaby, B.C. Samples were weighed, dried, crushed to 75% passing 2 mm, split to 250 g, and pulverized to 85% passing 75 microns. Samples were then fire assayed for Au (50 g) and sodium peroxide fusion ICP-MS finish for 34 elements.

QA/QC is done in house by Doré Copper geologists with oversight from the Vice President Exploration. The check samples (blanks and standards – 4% of total samples with another 2% of core duplicates taken on quarter split core) that were inserted into the sample batches are verified against their certified values and are deemed a pass if they are within 3 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 re-assayed.

Sylvain Lépine, M.Sc, P.Geo, 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.

Table 1. Doré Ramp Drill Assays Highlights (LDR-22-01W2 corrected)

1. The true width of the structures intersected is estimated at approximately 80% of the downhole width.
2. Reported in news release dated September 12, 2022.

Figure 1. Isometric View and Cross-Section of the Doré Ramp Deposit Showing the Location of the New Copper-Gold Mineralized Zone (LDR-22-01W2 corrected)

About Doré Copper Mining Corp.

Doré Copper Mining Corp. aims to be the next copper producer in Québec 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 mill¹. The Corporation has delivered its PEA in May 2022 and is proceeding with a feasibility study.

The Corporation has consolidated a large land package in the prolific Lac Doré/Chibougamau and Joe Mann mining camps that has historically produced 1.6 billion pounds of copper and 4.4 million ounces of gold². The land package includes 13 former producing mines, deposits and resource target areas within a 60-kilometer radius of the Corporation’s Copper Rand Mill.