First Mining Announces $50 Million Bought-Deal Offering of Common Shares

NOT FOR DISTRIBUTION TO UNITED STATES NEWS WIRE SERVICES OR FOR DISSEMINATION IN THE UNITED STATES

Base Shelf Prospectus Accessible and Prospectus Supplement to be Accessible on SEDAR+

VANCOUVER, British Columbia, Sept. 17, 2026 (GLOBE NEWSWIRE) — First Mining Gold Corp. (“First Mining” or the “Company”) (TSX: FF) (FRANKFURT: FMG) is pleased to announce that it has entered into an agreement with Haywood Securities Inc., ATB Cormark Capital Markets, and National Bank Financial Inc. acting as co-lead underwriters and joint bookrunners, on behalf of a syndicate of underwriters (collectively, the “ Underwriters “), pursuant to which the Underwriters have agreed to purchase, on a bought-deal basis, 59,530,000 common shares of the Company (the “ Common Shares ”) at a price of $0.84 per Common Share (the “ Offering Price ”) for aggregate gross proceeds to the Company of $50,005,200 (the “ Offering ”). The Underwriters have been granted an option (an “ Over-Allotment Option “) to purchase up to an additional 15% of the number of Common Shares issuable under the Offering at the Offering Price, exercisable in whole or in part up to 30 days following the closing of the Offering, which may be exercised to cover over-allotments, if any, and for market stabilization purposes.

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.

A welcome email is on its way. If you don't see it, please check your junk folder.

The Common Shares will be offered by way of a prospectus supplement (the “ Supplement ”) to the Company’s base shelf prospectus dated February 23, 2026 (the “ Base Shelf Prospectus ”) in each of the provinces and territories of Canada (excluding Quebec). The Common Shares may also be offered by way of private placement in the United States and in offshore jurisdictions in accordance with applicable securities laws and where doing so would not require a prospectus, registration statement, offering memorandum or similar document, or create reporting or other obligations for the Company. The Offering is expected to close on or about September 24, 2026, and is subject to customary closing conditions, including but not limited to the Company receiving all necessary regulatory approvals, including the approval of the Toronto Stock Exchange (the “ TSX ”).

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 is accessible, and the Supplement will be accessible within two business days from the date hereof, under the Company’s profile on SEDAR+ at www.sedarplus.ca .