VANCOUVER, BC, May 28, 2025 /PRNewswire/

First Mining Gold Corp. ("First Mining" or the "Company") (TSX: FF) (OTCQX: FFMGF) (FRANKFURT: FMG) is pleased to announce initial drilling results from the 2025 drilling program at its Duparquet Gold Project ("Duparquet Project" or the "Project") located in the Abitibi region of Quebec, Canada. The Company commenced its 2025 drilling program at the Duparquet Project in March, with one drill rig targeting the Miroir discovery and a second drill rig added in April to further support and accelerate the program to complete an estimated 18,000 m of drilling as part of the 2025 campaign.

The newly discovered Miroir target remains an excellent expansion opportunity where the 2025 drilling program and strategy is focused on further delineating the near surface extent of the mineralization footprint. The initial drill holes tested a zone extending approximately 100 m along strike from the initial discovery hole DUP24-048. Multiple significant intercepts of gold mineralization have been returned from this drilling, confirming and expanding the known extent of mineralization at Miroir. Highlights include near surface mineralization intercepts from drill hole DUP25-052 that returned 2.77 g/t Au over 11.1 m, including 4.36 g/t Au over 6.5 m, and drill hole DUP25-054 that returned 1.41 g/t Au over 11.9 m, including 2.52 g/t Au over 5.25 m, demonstrating encouraging grade and widths of gold mineralization within this shallow target that remains open for expansion (Figure 1).

"Our exploration drilling continues to demonstrate significant resource growth potential by delineating new discovery zones as well as demonstrating the continuity of mineralization along strike and at depth within underexplored areas of the Duparquet Gold Project," stated Dan Wilton, CEO of First Mining. "The confirmation of the continuity of near-surface mineralization in the Valentre and Miroir areas demonstrates that this well-established resource, already one of the largest in Quebec, can continue to grow. Duparquet is emerging as one of the largest gold development projects in Quebec and we are continuing to advance it through the development process."

Further strong results also include assays from a secondary target within a dual-purpose exploration drill hole at Miroir, where the depth extension of mineralization at the Valentre target, located 225 m south of Miroir, has now been successfully intersected at a vertical depth of 335 m. Within the secondary target, drill hole DUP25-054 returned 3.96 g/t Au over 9.3 m from 409.7 m to 419.0 m, including 5.71 g/t Au over 5.8 m, confirming a large extension and continuity of gold mineralization at the Valentre target along a key plunge. The assay results returned from the Valentre target continues to demonstrate continuity in grade and furthermore continues to validate the open-ended mineralization at Valentre.

Assay highlights from the 1, 140 metres completed across the initial six drill holes of the 2025 program are shown in Table 1, with a full list of assays returned in Table 2 and collar details in Table 3.

Table 1: Selected Significant Drill Intercepts, 2025 Program – Miroir and Valentre Targets

Duparquet 2025 Exploration Program Updates

Exploration activities are ongoing at the Duparquet Project with two drill rigs actively advancing at key resource growth targets through to the fall. Regional field campaigns will be commencing at the end of May 2025 with a focus on target generation across favourable lithologies and structures. The North Zone drilling will continue to focus on testing the syenite-mafic volcanic contact that has previously demonstrated an ability to host higher grade gold mineralization. Drilling at the South Zone will be targeting the extension of mineralization below the historical Donchester mine workings. Additional targets to be followed up on is the Aiguille Target, where drilling will be following up on the two discovery holes to further drill test the target's open-ended potential. A plan map of the key targets for exploration drilling activities is shown in Figure 2.

Additional Details on the Miroir and Valentre Drilling

Miroir

The 2025 Miroir drilling is focused on further delineating the extent of mineralization around the 2024 discovery hole, DUP24-048, that returned 3.12 g/t Au over 19.35 m close to surface. An area of approximately 100 m along strike has thus far been drill tested with six drill holes intersecting seven unique significant mineralization intervals including DUP25-052 that returned 2.77 g/t Au over 11.1 m, including 4.36 g/t Au over 6.5 m. The mineralized intercepts confirm the open-ended nature of the Miroir target.

Valentre

The objective of the 2025 drilling campaign at the Valentre target is to evaluate grade continuity and to refine the understanding of higher-grade mineralized zones at depth through a targeted drilling campaign. A dual-target hole, DUP25-054, was designed to drill test both the Miroir and the Valentre targets. Significant results returned from DUP25-054 for the Valentre target are 3.96 g/t Au over 9.3 m, including 5.71 g/t Au over 5.8 m at a depth of approximately 330 m below surface.

About the Duparquet Gold Project

The Duparquet Project is geologically situated in the southern part of the Abitibi Greenstone Belt and is geographically located approximately 50 km north of the city of Rouyn-Noranda. The Project benefits from easy access and proximity to an existing workforce and infrastructure. The Duparquet Project currently hosts an NI 43-101 compliant gold resource of 3.44 million ounces in the Measured & Indicated category, grading 1.55 g/t Au, and an additional 2.64 million ounces in the Inferred category, grading 1.62 g/t Au.

Analytical Laboratory and QA/QC Procedures

All sampling completed by First Mining within its exploration programs is subject to a Company standard of internal quality control and quality assurance (QA/QC) programs. Core samples from the 2025 drilling program at Duparquet were sent to AGAT Laboratories for analysis.

Qualified Person

James Maxwell, P.Geo., VP, Exploration and Project Operations for First Mining, is a "Qualified Person" for the purposes of NI 43-101 Standards of Disclosure for Mineral Projects and has reviewed and approved the scientific and technical disclosure contained in this news release.

About First Mining Gold Corp.

First Mining is a gold developer advancing two of the largest gold projects in Canada, focusing on the Springpole Gold Project in northwestern Ontario and the Duparquet Gold Project in Quebec.

Cautionary Note Regarding Forward-Looking Statements

This news release includes certain "forward-looking information" and "forward-looking statements". Forward-looking statements are based on First Mining's current beliefs as well as various assumptions made by them. Actual results and future events could differ materially from those anticipated in such statements.

Cautionary Note to United States Investors

The Company is a "foreign private issuer" and is eligible to rely upon the Canada-U.S. Multi-Jurisdictional Disclosure System, and is therefore permitted to prepare the technical information contained herein in accordance with applicable securities laws.