Mr. Daniel Wilton reports

FIRST MINING CLOSES $57.5 MILLION BOUGHT-DEAL OFFERING INCLUDING FULL EXERCISE OF OVER-ALLOTMENT OPTION

First Mining Gold Corp. has closed its previously announced bought deal public offering. Pursuant to the offering, the company has issued 68,459,500 common shares of the company at a price of 84 cents per common share for aggregate gross proceeds of $57,505,980, including full exercise of the overallotment option.

The offering was completed through a syndicate of underwriters co-led by Haywood Securities Inc., ATB Cormark Capital Markets and National Bank Financial Inc., and including Canaccord Genuity Corp., SCP Resource Finance LP, Beacon Securities Ltd., H.C. Wainwright & Co. LLC, Ventum Financial Corp., and BMO Capital Markets.

The net proceeds from 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.

The offering was completed by way of a prospectus supplement to the company's base shelf prospectus dated Feb. 23, 2026, which supplement was filed on Sept. 21, 2026, with the securities commissions and other similar regulatory authorities in each of the provinces and territories of Canada. The common shares were also offered by way of private placement in the United States and in offshore jurisdictions in accordance with applicable securities laws, and where doing so did not require a prospectus, registration statement, offering memorandum or similar document, or create reporting or other obligations for the company.

Access to the base shelf prospectus, the supplement and any amendments to such documents are 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 and the supplement are accessible under the company's profile on SEDAR+. Copies of the base shelf prospectus, the supplement and any amendment to such documents may be obtained, without charge, from: (i) Haywood Securities Inc., by phone at 604-697-7126 or by e-mail at ecm@haywood.com; (ii) ATB Cormark Capital Markets, by phone at 416-943-6701 or by e-mail at ecm@atb.ca; or (iii) National Bank Financial Inc. by phone at 416-869-8414 or by e-mail at NBF-Syndication@bnc.ca.

The offering remains subject to receipt of final approval of the Toronto Stock Exchange.

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 federal environmental assessment for the Springpole project was approved in June, 2026, and the Duparquet gold 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 a 20-per-cent project interest in the Pickle Crow gold project in Ontario and large equity interest in Seva Mining Corp.

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

We seek Safe Harbor.