First Mining Gold Corp. (TSX: FF) (OTCQX: FFMGF) (FRANKFURT: FMG) is pleased to announce additional drilling results from the 2025 exploration program at its Duparquet Gold Project located in the Abitibi region of Quebec, Canada. The Company has been actively drilling at the Duparquet Project and has completed ~16,000 m of drilling since March 2025, with a focus on advancing key resource expansion targets. Remaining assay results from the 2025 program are pending, and the Company will provide further updates as results are received and interpreted.

• Aiguille Zone now delineated over 100 m strike length, highlighted by drill hole DUP25-058 returning 1.43 g/t Au over 24.1 m, including 4.56 g/t Au over 4.0 m
• Exploration drilling program continues through the month of September with ~16,000 m completed in 2025 to date

Figure 1: Plan view of the CVD, Aiguille, and Miroir target areas. (CNW Group/First Mining Gold Corp.)

Figure 2: Plan view map of Duparquet geology and mineral resource with main targets around the Project core area. (CNW Group/First Mining Gold Corp.)

Figure 3: Cross section and plan view of the recently completed drilling at the Aiguille Zone, highlighting select drill holes and significant intercepts downhole. The cross section is looking west. (CNW Group/First Mining Gold Corp.)

Figure 4: Aiguille plan view and north-looking long section, highlighting recent drill results and outlining future drill targets. (CNW Group/First Mining Gold Corp.)

Figure 5: Long section view of the CVD area highlighting the drill density and significant Au intercepts. (CNW Group/First Mining Gold Corp.)

Highlights from the latest drilling include the continued advancement of the Aiguille discovery zone. Drill hole DUP25-058 returned 1.43 g/t Au over 24.1 m, including 4.56 g/t Au over 4.0 m, further extending the target eastward along strike. Originally discovered in 2024, the Aiguille Zone returned 8.99 g/t Au over 3.1 m in DUP24-044 (see news release dated January 20, 2025). With the latest results, the Aiguille target has now been delineated over an approximate strike length of 100 m. The zone remains open, and follow-up drilling will focus on further defining both its vertical and strike extents.

“Our exploration teams continue to build on our drilling success at Duparquet with the advancement of priority target areas proximal to the existing mineral resource, aimed at bolstering continuity and endowment in support of our development vision,” stated Dan Wilton, CEO of First Mining. “With a highly productive drill program to date, we look forward to further strong results-driven updates on the Project.”

Drilling at the Valentre target has continued in 2025, with recent assay results returning 2.80 g/t Au over 3.25 m, including 4.93 g/t Au over 1.75 m in drill hole DUP25-057. Ongoing drilling at the Central Duparquet-Valentre-Dumico target, together with the adjacent Aiguille and Miroir targets, continues to reinforce the area as an emerging resource growth centre that could have synergies with mining development scenarios. Furthermore, with the expansion of the Aiguille and Miroir targets, the Company has demonstrated a favourable area with a concentration of gold mineralization spanning 1.5 km by 0.5 km (See Figure 1).

The latest completed holes total 1,053 metres of the 2025 program and assay highlights 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 – Aiguille and Valentre Targets

Duparquet 2025 Exploration Program Updates

Exploration activities at the Duparquet Project continue to advance, with ~16,000 m drilled in 2025 to date. Drilling has been strategically focused on key resource expansion targets including CVD, Miroir, Aiguille, North Zone, South Zone, and the newly discovered Minuit Zone, where programs are aimed at building on the Project’s strong growth potential (Figure 2). In parallel, regional field programs are progressing to refine and advance additional targets toward future drill readiness.

Additional Details on the Aiguille and CVD Targets

Aiguille

The 2025 Aiguille drilling program is focused on expanding the extent of mineralization along strike and plunge of the two discovery holes completed in 2024. Recent drilling returned 1.43 g/t Au over 24.1 m, including 4.56 g/t Au over 4.0 m, in drill hole DUP25-058 (Figure 3). Mineralization is hosted within alternating brecciated and altered basalt, argillite, and syenite units, with up to 5% very fine-grained and medium-grained pyrite. Mineralization is consistent along interpreted east-west trending D2 structures, which are characterized by intense brecciation and shearing.  Drilling to date has extended the mineralized strike length at Aiguille to approximately 100 m, and the zone remains open both at depth and along strike, particularly toward surface and eastward (Figure 4).

Central Duparquet – Valentre – Dumico

Drilling at the CVD target area has been further advanced with drill holes DUP25-055 and DUP25-057 (Table 2). Notably, DUP25-057 returned 2.80 g/t Au over 3.25 m, including 4.93 g/t Au over 1.75 m. Mineralized intersections are hosted in brecciated silica-altered basalt or syenite, containing up to 5% very fine-grained disseminated pyrite.

The exploration strategy at the CVD target is focused on expanding the mineralized footprint and demonstrating continuity along strike and at depth. Results will be incorporated into an updated 3D geological model to guide future drilling programs and support the potential inclusion of the CVD target in future mineral resource estimates (Figure 5).

Table 2: Latest Assay Results from 2025 Drill Program 

Table 3: 2025 Drill Hole Locations – Minuit, Aiguille, Valentre Zones

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, including road, rail and hydroelectric grid power. 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. First Mining completed a Preliminary Economic Assessment¹ on the Project in 2023.

The Duparquet Project totals approximately 5,800 hectares focused on an area of 19 km of strike length along the prolific Destor-Porcupine Fault Zone, along with numerous mineralized splays and influential secondary lineaments. The Duparquet Project includes the past-producing Beattie, Donchester and Duquesne mines as well as the Central Duparquet, Dumico and Pitt Gold deposits.

¹ Further details on the Duparquet PEA can be found in the technical report entitled “NI 43-101 Technical Report: Preliminary Economic Assessment, Duparquet Gold Project, Quebec, Canada” dated October 20, 2023, which was prepared for First Mining by G Mining Services Inc. in accordance with NI 43-101 and is available under First Mining’s SEDAR+ profile at www.sedarplus.ca

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 which include the insertion of certified reference materials, blank materials and a level of duplicate analysis. Core samples from the 2025 drilling program at Duparquet were sent to AGAT Laboratories, with sample preparation in Val d’Or, Quebec and analysis in Thunder Bay, Ontario, where they were processed for gold analysis by 50 gram fire assay with an atomic absorption finish. Samples from selected holes were sent to AGAT Laboratories in Calgary, Alberta, for multi-element analysis (including silver) by inductively coupled plasma (ICP) method with a four acid digest. AGAT Laboratories systems conform to requirements of ISO/IEC Standard 17025 guidelines and meets assay requirements outlined for NI 43-101.

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, the Springpole Gold Project in northwestern Ontario, where we have commenced a Feasibility Study and permitting activities are on-going with a final Environmental Impact Statement / Environmental Assessment for the project submitted in November 2024, and the Duparquet Gold Project in Quebec, a PEA-stage development project located on the Destor-Porcupine Fault Zone in the prolific Abitibi region. First Mining also owns the Cameron Gold Project in Ontario and a 30% project interest in the Pickle Crow Gold Project.

First Mining was established in 2015 by Mr. Keith Neumeyer, founding President and CEO of First Majestic Silver Corp.

ON BEHALF OF FIRST MINING GOLD CORP.

Daniel W. Wilton
Chief Executive Officer and Director