First Mining Files Final Base Shelf Prospectus and Registration Statement

Press Release

February 24, 2026 – Vancouver, BC – First Mining Gold Corp. (“First Mining” or the “Company”) (TSX: FF) (OTCQX: FFMGF) (FRANKFURT: FMG) announces that it has obtained a receipt for as final short form base shelf prospectus (the “Final Shelf Prospectus”) filed with the securities regulatory authorities in each of the provinces and territories of Canada, and its corresponding registration statement on Form F-10 (the “Registration Statement”) has been filed with the United States Securities and Exchange Commission (the “SEC”)  under the U.S./Canada Multijurisdictional Disclosure System, but has not yet become effective. The filing replaces the previous base shelf prospectus of the Company dated January 23, 2024.

The filing of the Final Shelf Prospectus and the Registration Statement is consistent with the Company’s past practice to provide First Mining with greater financial flexibility. The Company has not entered into any agreements or arrangements to authorize or offer any Securities (as defined below) at this time.

The Final Shelf Prospectus and the Registration Statement will allow First Mining to undertake offerings of common shares, preferred shares, warrants, subscription receipts and units (collectively, the “Securities”), or any combination thereof, up to an aggregate total of C$500 million from time to time during the 25-month period that the Final Shelf Prospectus remains effective. The Securities may be offered in amounts, at prices and on terms to be determined at the time of sale and, subject to applicable regulations, may include “at-the-market” transactions, public offerings or strategic investments. The specific terms of any offering of Securities, if any, including the use of proceeds from such offering, will be set forth in a shelf prospectus supplement pertaining to such offering to be filed with applicable securities regulatory authorities.  The securities may not be sold nor may offers to buy be accepted prior to the time the Registration Statement becomes effective.

Copies of the Final Shelf Prospectus and the Registration Statement can be found, respectively, under the Company’s SEDAR+ profile at www.sedarplus.ca and on EDGAR at www.sec.gov, or may be obtained by request to Richard Huang, Vice President, Corporate Development & Corporate Secretary, Suite 2070 – 1188 West Georgia Street, Vancouver, British Columbia  V6E 4A2, Canada, or to info@firstmininggold.com.

No securities regulatory authority has either approved or disapproved the contents of this news release. This news release does not constitute an offer to sell or a solicitation of an offer to buy any securities of the Company in any jurisdiction in which such offer, solicitation or sale would be unlawful.

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 we have commenced a Feasibility Study and permitting activities are on-going with a final Environmental Impact Statement / Environmental Assessment for the project submitted in November 2024, and the Duparquet Gold Project in Quebec, a PEA-stage 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 30% project interest in the Pickle Crow Gold Project.

First Mining was established in 2015 by Mr. Keith Neumeyer, founder and CEO of First Majestic Silver Corp.

ON BEHALF OF FIRST MINING GOLD CORP.

Daniel W. Wilton
Chief Executive Officer and Director

For further information, please contact:

Toll Free: 1 844 306 8827 | Email: info@firstmininggold.com
Paul Morris | Director, Investor Relations | Email: paul@firstmininggold.com

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