Vancouver – September 15, 2026 -- First Mining Gold Corp. (TSX: FF; OTCQX: FFMGF; FRANKFURT: FMG) has reported new high-grade gold intercepts from its 2026 drilling program at the Miroir target within the Duparquet Gold Project in Quebec's Abitibi region, extending the known mineralized strike length to approximately 220 metres from 150 metres in 2025.
Drill hole DUP26-093 returns 5.26 g/t gold over 19.55 metres
The intercept, from 182.0 m to 201.55 m depth, included 7.58 g/t Au over 12.95 m and a higher-grade section of 21.80 g/t Au over 1.0 m. Drill hole DUP26-096 returned 3.43 g/t Au over 28.0 m from 234.35 m to 262.35 m, including 10.36 g/t Au over 7.2 m, plus a secondary zone of 2.99 g/t Au over 4.6 m and 4.90 g/t Au over 2.7 m.
Additional holes confirm mineralization extends east, west and at depth
DUP26-095 returned 3.36 g/t Au over 15.8 m, including 15.10 g/t Au over 2.0 m, alongside a separate 3.54 g/t Au over 4.2 m zone including 7.28 g/t Au over 1.0 m. DUP26-092 returned 3.33 g/t Au over 5.0 m, including 7.20 g/t Au over 1.0 m, confirming a westward and depth extension of the mineralized system. The deposit remains open in all directions.
CEO Dan Wilton said the continued high-grade results at Miroir demonstrate the target's potential to become an important contributor to future resource growth at Duparquet.
Company drills 2,994 metres across 11 holes at Miroir in 2026 to date
The latest assays represent roughly 1,553 m of that total, part of a broader 15,000-metre exploration campaign that began in May 2026 and continues into Q4 2026. Mineralization at Miroir is hosted in a brecciated basalt-syenite package with silica alteration and 2-5% disseminated pyrite, spatially tied to northeast-southwest D2 deformation zones along an inferred basalt-syenite contact plunging east.
First Mining updates resource model using 48,000 metres of new drilling
The Company has initiated a revision of the Duparquet Project's mineral resource model to incorporate drilling completed since the current NI 43-101 estimate's September 12, 2022 effective date. That estimate currently stands at 3.44 million ounces gold in the Measured & Indicated category at 1.55 g/t Au, plus 2.64 million ounces Inferred at 1.62 g/t Au. Duparquet spans roughly 5,800 hectares and 19 km of strike along the Destor-Porcupine Fault Zone, encompassing the past-producing Beattie, Donchester and Duquesne mines. Additional assay results from the 2026 program remain pending.