First Mining Reports 5.26 g/t Au over 19.55 m as Drilling Expands Miroir Discovery at the Duparquet Project

First Mining Gold Corp. (FF) has released initial 2026 drill assays from the Miroir target at its Duparquet Gold Project in Quebec. First Mining first identified the Miroir target in 2024 and drilled through it in 2025.

Key reported intercepts are:

• DUP26-093: 5.26 g/t Au over 19.55 m from 182.0 m to 201.55 m
• DUP26-093 including: 7.58 g/t Au over 12.95 m
• DUP26-093 and including: 21.80 g/t Au over 1.0 m
• DUP26-096: 3.43 g/t Au over 28.0 m from 234.35 m to 262.35 m
• DUP26-096 including: 10.36 g/t Au over 7.20 m
• DUP26-096 also: 2.99 g/t Au over 4.6 m and 4.90 g/t Au over 2.7 m
• DUP26-095: 3.36 g/t Au over 15.8 m from 1.2 m to 17.0 m
• DUP26-095 including: 15.10 g/t Au over 2.0 m
• DUP26-095 also: 3.54 g/t Au over 4.2 m
• DUP26-092: 3.33 g/t Au over 5.0 m and 2.61 g/t Au over 6.2 m
• DUP26-092 also: 11.80 g/t Au over 1.0 m

The company states that the 2026 drilling extended the Miroir strike length from approximately 150 m to approximately 220 m, with extensions to the east, west, and at depth.

Disclosure indicates that the reported assays represent approximately 1,553 m of drilling from a total of 2,994 m across 11 holes drilled this year at Miroir. Table 4, however, lists only five holes totaling 1,553 m. The final 12 samples for DUP26-096 remain pending.

True widths have not yet been determined. Assay values are reported uncut. No cutoff grade is stated.

First Mining Gold Corp. (FF) is a developer-stage company with a large resource base and a market capitalization near C$1.3 billion. The Duparquet project holds 3.44 moz Measured and Indicated (M&I) resources and 2.64 moz Inferred resources, while Springpole carries 3.1 moz in Probable Reserves and larger M&I resources.

The Miroir results represent a positive step-out at an emerging exploration target within the PEA-stage Duparquet complex, though they are not yet resource ounces. The strike extension from about 150 m to 220 m is material at the target scale but small at the company scale.

The latest intercepts compare favourably with prior Miroir anchors:

• Prior strong anchor DUP25-064: 3.23 g/t Au over 25.9 m = 83.7 gram-metres.
• Prior high-grade anchor DUP25-085: 7.18 g/t Au over 8.0 m = 57.4 gram-metres.
• New DUP26-093: 5.26 g/t Au over 19.55 m = 102.8 gram-metres.
• New DUP26-096: 3.43 g/t Au over 28.0 m = 96.0 gram-metres.

The new results clear the prior anchor on gram-metres. The broader stock has already re-rated strongly over the last year, from about C$0.25 to near C$0.97, driven mainly by Springpole federal EA approval, PFS economics and Indigenous agreements. The market already assigns substantial option value to continued exploration success.

This release is genuinely positive but not yet transformational. It supports the exploration thesis and may feed a future resource update, but it would likely not by itself re-rate the equity by 15% given the company's size and existing resource base.

First Mining Gold Corp. is a gold developer with two principal Canadian assets. The Springpole Gold Project in Ontario features a 2025 Preliminary Feasibility Study (PFS) that outlines a 30,000 tonnes per day open-pit operation. The project is expected to produce approximately 330,000 ounces of payable gold per year for years 1-5, with an all-in sustaining cost (AISC) around US$877 per ounce during that period. Initial capital expenditure is estimated near US$1.1 billion, and the post-tax net present value at a 5% discount rate (NPV5) is US$2.1 billion at the US$3,100 per ounce base case. Federal environmental assessment (EA) approval for the project was received in June 2026.

The Duparquet Gold Project in Quebec is a PEA-stage project located on the Destor-Porcupine Fault Zone. It contains 3.44 million ounces of Measured and Indicated resources at 1.55 grams per tonne of gold and 2.64 million ounces of Inferred resources at 1.62 grams per tonne of gold. The current release targets the Miroir discovery area.

Other assets include a 20% carried interest in the Pickle Crow Gold Project and a large equity stake in Seva Mining Corp.

Prior-quarter financial context, not disclosed in today's release, indicates that cash and cash equivalents were C$37.3 million as of June 30, 2026, and working capital was C$18.7 million. The company reported a first-half 2026 net loss of C$18.9 million. The company is pre-revenue and carries a going-concern flag.