Mr. Daniel Wilton reports

FIRST MINING ANNOUNCES PUBLIC OFFERING AND NON-BROKERED PRIVATE PLACEMENT FOR UP TO $20 MILLION

First Mining Gold Corp. has entered into an agreement with Haywood Securities Inc., on behalf of a syndicate of agents, in connection with a commercially reasonable efforts, public offering of up to 27.8 million units of the company at a price of 18 cents per unit for aggregate gross proceeds to the company of up to $5,004,000.

Each unit will consist of one common share of the company and one-half of one common share purchase warrant. Each warrant will entitle the holder to acquire one common share of the company at a price of 27 cents per share at any time prior to the date that is 36 months following the applicable closing date.

The units issuable under the public offering will be offered pursuant to a prospectus supplement to the company's base shelf prospectus dated Jan. 23, 2024. The terms of the public offering will be described in the supplement, which will be filed with the securities regulators in each of the provinces and territories of Canada (excluding Quebec) and the units may also be offered by way of private placement in the United States and in offshore jurisdictions in accordance with applicable securities laws.

The agents have been granted an option to purchase up to an additional 15 per cent of the number of units issuable under the public offering at the unit offering price, exercisable in whole or in part, up to 48 hours prior to the closing of the public offering.

In addition, the company intends to complete a non-brokered private placement of up to 55.6 million units at the unit offering price and up to 22.73 million flow-through units at a price of 22 cents per flow-through unit for total gross proceeds of up to $15,008,600. Combined, the company expects to receive gross proceeds of up to $20,012,600 upon completion of the offering. Each flow-through unit will consist of one flow-through share and one-half of a warrant.

Each flow-through share will qualify as a flow-through share within the meaning of the Income Tax Act (Canada) and will be offered on a private placement basis to accredited investors in each of the provinces of Canada except Quebec) pursuant to applicable prospectus exemptions in accordance with National Instrument 45-106. All securities issued in connection with the non-brokered offering will have a statutory hold period of four months and one day from the closing date.

The net proceeds from the sale of units under the offering will be used to advance First Mining's Springpole and Duparquet gold projects as well as for general working capital and corporate purposes, as to be disclosed in the supplement. The gross proceeds from the sale of flow-through units will be used to incur eligible Canadian exploration expenses that qualify as flow-through mining expenditures, as such terms are defined in the Income Tax Act (Canada), related to the Springpole and Duparquet gold projects on or before Dec. 31, 2026. All qualifying expenditures will be renounced with an effective date no later than Dec. 31, 2025, to the initial purchasers of the flow-through units.

The public offering is expected to close on or about July 22, 2025, and the non-brokered offering is expected to close on or before Aug. 5, 2025. The closing of the offering is subject to certain conditions, including, but not limited to, the company receiving the approval of the Toronto Stock Exchange.

Access to the shelf prospectus, the supplement and any amendments to such documents is provided in accordance with securities legislation relating to procedures for providing access to a base shelf prospectus, a shelf prospectus supplement and any amendment to such documents. The shelf prospectus is accessible, and the supplement will be accessible within two business days from the date hereof, on SEDAR+. An electronic or paper copy of the supplement, the shelf prospectus and any amendment to the documents may be obtained, without charge, from Haywood Securities Inc. by e-mail at ecm@haywood.com and by providing the contact with an e-mail address or address, as applicable.

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 the company has commenced a feasibility study and permitting activities are continuing with a final environmental impact statement/environmental assessment for the project submitted in November, 2025, and the Duparquet project in Quebec, a PEA-stage (preliminary economic assessment) 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 portfolio of gold project interests, including the Pickle Crow gold project (being advanced in partnership with Firefly Metals Ltd.) and the Hope Brook gold project (being advanced in partnership with Big Ridge Gold Corp.).

First Mining was established in 2015 by Keith Neumeyer, founding president and chief executive officer of First Majestic Silver Corp.

We seek Safe Harbor.