EXHIBIT 99.1

First Mining Gold Corp.

Condensed Interim Consolidated Financial Statements

For the three and six months ended June 30, 2025 and 2024

(Presented in thousands of Canadian dollars unless otherwise noted)

(Unaudited)

FIRST MINING GOLD CORP.                     

CONDENSED INTERIM CONSOLIDATED STATEMENTS OF FINANCIAL POSITION

AS AT JUNE 30, 2025 AND DECEMBER 31, 2024

The condensed interim consolidated financial statements were approved by the Board of Directors:

The accompanying notes are an integral part of these condensed interim consolidated financial statements.

FIRST MINING GOLD CORP.

CONDENSED INTERIM CONSOLIDATED STATEMENTS OF NET LOSS AND COMPREHENSIVE LOSS  

FOR THE THREE AND SIX MONTHS ENDED JUNE 30, 2025 AND 2024  

The accompanying notes are an integral part of these condensed interim consolidated financial statements.

FIRST MINING GOLD CORP.

CONDENSED INTERIM CONSOLIDATED STATEMENTS OF CASH FLOWS

FOR THE SIX MONTHS ENDED JUNE 30, 2025 AND 2024

The accompanying notes are an integral part of these condensed interim consolidated financial statements.

FIRST MINING GOLD CORP.

CONDENSED INTERIM CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY

FOR THE SIX MONTHS ENDED JUNE 30, 2025 AND 2024

The accompanying notes are an integral part of these condensed interim consolidated financial statements.

FIRST MINING GOLD CORP.

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

1.  NATURE OF OPERATIONS

First Mining Gold Corp. (the “Company” or “First Mining”) is a public company which is listed on the Toronto Stock Exchange (the “TSX”) under the symbol “FF”, on the “OTCQX”, under the symbol “FFMGF”, and on the Frankfurt Stock Exchange under the symbol “FMG”. The Company’s head office and principal address is Suite 2070 - 1188 West Georgia Street, Vancouver, British Columbia, Canada, V6E 4A2.

First Mining was incorporated on April 4, 2005 and changed its name to First Mining Gold Corp. in January 2018.

First Mining is advancing a portfolio of gold projects in Canada, with the most advanced projects being the Springpole Gold Project in northwestern Ontario and the Duparquet Gold Project in the Abitibi region of Québec. First Mining’s portfolio of gold projects in eastern Canada also includes the Cameron Project. In addition, the Company holds a 30% interest in PC Gold Inc., the legal entity which holds the Pickle Crow Gold Project, which is being advanced by FireFly Metals Ltd. (“FireFly Metals”), and a 20% direct project interest in the Hope Brook Project until July 31, 2025 (Note 16(b)).

The Company’s unaudited condensed interim consolidated financial statements (“financial statements”) have been prepared on a going concern basis, which contemplates that the Company will be able to continue its operations for at least twelve months from June 30, 2025 and will be able to realize its assets and discharge its liabilities and commitments in the normal course of business.  The Company has not generated revenue from operations to date and will require additional financing or outside participation to undertake further advanced exploration of its mineral properties.

FIRST MINING GOLD CORP.

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS

2.  BASIS OF PRESENTATION

These financial statements have been prepared in accordance with International Financial Reporting Standards as issued by the International Accounting Standards Board (“IFRS Accounting Standards”) applicable to the preparation of interim financial statements under International Accounting Standard 34 Interim Financial Reporting. These financial statements do not include all disclosures required for annual financial statements. Accordingly, they should be read in conjunction with the Company’s audited financial statements for the years ended December 31, 2024 and 2023.

The financial statements are presented in thousands of Canadian dollars, unless otherwise noted, and tabular amounts are presented in thousands of Canadian dollars. These consolidated financial statements include the accounts of the Company and its subsidiaries. The functional currency of the Company and its subsidiaries is the Canadian dollar.  

In preparing the Company’s financial statements for the three and six months ended June 30, 2025, the Company used the consistent accounting policies, methods of computation and accounting policy judgments and estimates as in the annual consolidated financial statements for the year ended December 31, 2024. Additionally, the areas of estimation uncertainty remain unchanged from those disclosed in the annual consolidated financial statements.

Certain new accounting standards and interpretations have been published that are either applicable in the current year or not mandatory for the current period. We have assessed these standards, including Amendments to IAS 1 - Non-current Liabilities with Covenants, and determined they do not have a material impact on the Company in the current reporting period. In addition, the following standards have been issued by the International Accounting Standards Board (“IASB”) and we are currently assessing the impact on our consolidated financial statements.

No standards have been early adopted in the current period. The Company is still assessing whether any of the new standards are expected to have a material impact on its consolidated financial statements.

The accounts of material subsidiaries are prepared for the same reporting period as the parent company. All subsidiaries apply consistent accounting policies. Inter-company transactions, balances and unrealized gains or losses on transactions are eliminated. The following table highlights the Company’s material subsidiaries with their projects:

These financial statements were approved by the Board of Directors on August 11, 2025.

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

3.  ASSETS HELD FOR SALE

As at June 30, 2025, the Company classified the remaining 20% ownership of the Hope Brook Project as held for sale. Subsequent to June 30, 2025, the Company completed the sale of its 20% ownership stake to Big Ridge Gold Corp for consideration of $3 million in cash and 7 million common shares of Big Ridge (Note16(b)).

4.  MARKETABLE SECURITIES

The Company’s marketable securities are classified as FVTOCI and are carried at fair value. The movements in marketable securities during the six months ended June 30, 2025 and year ended December 31, 2024 are summarized as follows:

The Company owns securities of publicly traded companies. The investments where the Company does not have significant influence are classified as marketable securities which are designated as FVTOCI.

As at June 30, 2025, the Company held common shares of NexGold Mining Corp., Grid Metals Corp. and Patriot Lithium Limited.

5.  PREPAID EXPENSES AND OTHER RECEIVABLES

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

6.  MINERAL PROPERTIES

As at June 30, 2025 and December 31, 2024, the Company had the following mineral properties:

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

6.  MINERAL PROPERTIES (continued)

The Company has various underlying agreements and commitments with respect to its mineral properties, which define annual or future payments in connection with royalty buy-backs or maintenance of property interests, the most significant of which are discussed below.

a) Duparquet Project

As at June 30, 2025, the Company’s provision for environmental remediation activities is $3,396,000 (December 31, 2024 - $3,035,000). The environmental remediation includes site preparation, construction of a storage area, construction of an access road, excavation and transportation of mining material, and site restoration and rehabilitation of the storage area. The Company has been working with the Ministry of Environment, the Fight Against Climate Change, Wildlife and Parks (“MELCCFP”) and submitted a permit to start work in 2025. The environmental remediation estimate is based on the current work plan. During the period ended June 30, 2025, the Company recorded an increase in estimated remediation costs of $361,000 (year ended December 31, 2024 - $1,535,000). The final environmental remediation cost may vary depending on feedback received from MELCCFP and the execution of the work.

b) Hope Brook Project

First Mining owns a 20% interest in the Hope Brook Gold Project as of June 30, 2025. First Mining’s joint venture partner is Big Ridge Gold Corp. (“Big Ridge”) who owns the remaining 80% of the Hope Brook Project and is the current operator. As at June 30, 2025, the Company’s interest in this project has been reclassified as assets held for sale (Note 3).

7.  INVESTMENT IN PC GOLD INC.

Pursuant to a definitive Earn-in agreement (“Earn-in”) the Company and FireFly Metals executed on March 12, 2020, comprised of two stages, on June 9, 2021, the Company announced completion of the Stage 1 earn-in and accordingly FireFly Metals obtained a 51% ownership of the PC Gold legal entity. First Mining received the scheduled 100,000,000 FireFly Metals shares and executed the joint venture shareholders agreement.

Following the completion of the Stage 1 earn-in by FireFly Metals, the Company’s percentage ownership of its former subsidiary, PC Gold, was reduced from 100% to 49%, which led to a loss of control and the resulting deconsolidation of PC Gold Inc. from First Mining’s financial statements.

First Mining determined that its then 49% investment in the common shares of PC Gold gave it significant influence over PC Gold, requiring PC Gold to be recorded in First Mining’s financial statements using the equity method of accounting as an investment in associate.  Upon the completion of the Stage 2 earn-in by FireFly Metals in August 2021, the Company’s percentage ownership reduced from 49% to 30%.

The initial recognition of the investment in an associate was accounted for based on an estimated fair value using a market approach to value Pickle Crow’s inferred resources on a per unit of metal basis derived from comparable gold project transactions. As at June 30, 2025, the Company owns a 30% interest in PC Gold Inc. and maintains significant influence, which requires the investment to be accounted for using equity accounting.

As at June 30, 2025, the carrying value of the investment in PC Gold Inc. was $21,524,000 (December 31, 2024 - $21,527,000).

The subsequent equity accounting for PC Gold is based on audited results that are publicly available information for the year ended June 30, 2024, and on the unaudited year ended June 30, 2025.

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

7. INVESTMENT IN PC GOLD INC. (continued)

As at June 30, 2025, the Company has recorded an option liability of $3,974,000 (December 31, 2024 - $3,974,000), which represents the additional net dilution that would result from FireFly Metals completing its additional 10% equity interest in PC Gold Inc. Following receipt of $3,000,000 under this option, First Mining’s ownership would reduce to 20%. The FireFly Metals Earn-In Agreement requires First Mining to contribute its pro-rata share of environmental reclamation funding, which was 30% as at June 30, 2025.

As at June 30, 2025, the Company has recorded a liability for reclamation funding of $151,000 (December 31, 2024 - $151,000), which is in line with FireFly Metals’ estimate of the environmental reclamation provision.

8. SILVER STREAM DERIVATIVE LIABILITY

a) Silver Purchase Agreement Overview and Consideration Received

On June 10, 2020, the Company entered into a silver purchase agreement (the “Silver Purchase Agreement”) with First Majestic Silver Corp. (“First Majestic”), which closed on July 2, 2020. Under the terms of the Silver Purchase Agreement, First Majestic agreed to pay First Mining total consideration of US$22.5 million (approx. $30.6 million as at the closing date), in three tranches, for the right to purchase 50% of the payable silver produced from the Springpole Gold Project over the life of the project (the “Silver Stream”) and also received 30 million common share purchase warrants of First Mining (subsequently adjusted to 32 million common share purchase warrants in accordance with the terms of the Silver Purchase Agreement).

Each share purchase warrant entitles First Majestic to purchase one common share of First Mining at an exercise price of $0.40 for a period of five years (subsequently re-priced to $0.374 in accordance with the terms of the Silver Purchase Agreement). The fair value of warrants is determined using Black-Scholes option pricing model.

First Mining has the right to repurchase 50% of the Silver Stream for US$22.5 million (approximately $30.7 million as at June 30, 2025) at any time prior to the commencement of production at Springpole (the “Buy-Back Right”). A Monte Carlo simulation was performed to evaluate the buy-back option under the Silver Stream agreement.

Per the Silver Purchase Agreement, First Majestic paid US$10 million ($13.7 million) to First Mining on the July 2, 2020, closing date, with US$2.5 million ($3.3 million) paid in cash and the remaining US$7.5 million ($10.4 million) paid in 805,698 common shares of First Majestic (“Tranche 1”).

Upon announcement of the Pre-Feasibility Study on March 4, 2021, First Mining received US$7.5 million ($9.8 million) from First Majestic, with US$3.75 million ($4.8 million) paid in cash and the remaining US$3.75 million ($5.0 million) paid in 287,300 common shares of First Majestic (“Tranche 2”). The final tranche (“Tranche 3”) of US$5.0 million ($6.5 million) is payable by First Majestic upon First Mining receiving approval of a federal or provincial environmental assessment for the Springpole Gold Project, which is to be paid half in cash and half in shares of First Majestic. Please refer to the details of the amending agreement below.

The Silver Stream has an initial term of 40 years from July 2, 2020. The term is automatically extended by successive 10-year periods as long as the life of mine continues for the Springpole Gold Project. If, upon expiration of the term of the Silver Purchase Agreement, the Company has not sold to First Majestic an amount of silver sufficient to reduce the Advance Payment to $nil, then a refund of the uncredited balance, without interest shall be due and owing by the Company to First Majestic.

The silver delivered to First Majestic may be sourced from the Springpole Gold Project, or the Company may substitute any required refined silver with refined silver from a source other than the Springpole Gold Project, with the exception of silver purchased on a commodity exchange.

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

8. SILVER STREAM DERIVATIVE LIABILITY (continued)

On March 28, 2025, the Company received the final payment of US$5 million ($7.2 million) from First Majestic in connection with the Silver Stream. The parties entered into an amending agreement to the Silver Purchase Agreement on March 13, 2025 (“Amending Agreement”) to amend the terms of the final payment due from First Majestic under the Silver Purchase Agreement (the “Tranche 3 Payment”). Under the Amending Agreement, the Tranche 3 payment would be made earlier than originally scheduled and would consist of US$5 million in cash, with no requirement for the completion of the environmental assessment.

As consideration for amending the terms of the Tranche 3 payment, the Company has amended the terms of the common share purchase warrants (the “Warrants”) that were issued to First Majestic on July 2, 2020 under the terms of the Silver Purchase Agreement. The 32,050,228 Warrants that were issued to First Majestic had an exercise price of $0.374 per Warrant and were set to expire on July 2, 2025. The Company has revised the exercise price of the Warrants to $0.20 and extended the expiry date of the Warrants to March 31, 2028. Pursuant to the terms of the amended Warrants, the Company can accelerate the expiry date of the Warrants if the closing price of the Company’s common shares on the TSX equals or exceeds $0.30 for 45 consecutive trading days, to the date which is 30 days following the dissemination of a news release announcing the acceleration. As a result, the fair value of the Warrants, amounting to $1.3 million, was recognized in the statements of changes in equity, with the fair value determined using Black-Scholes option pricing model. All other terms of the Warrants remain unchanged.

b) Silver Stream Derivative Liability Fair Value

The Company has determined that the Silver Stream is a standalone derivative measured at FVTPL. The estimated fair value of the Silver Stream derivative liability is determined using a discounted cash flow model which incorporates a Monte Carlo simulation, with the following key input assumptions: 1) Observable assumptions including implied volatility of COMEX silver, COMEX silver future curve, silver spot price, USD risk-free rate, USD/CAD foreign exchange rates, and share price of the Company, and 2) Unobservable assumptions including the Company’s credit spread, historical volatility of the warrant and payable silver quantities. The fair value of the Silver Stream derivative liability is a Level 3 measurement.

The fair value of the Silver Stream derivative liability is valued using a Monte-Carlo simulation, with gains or losses recorded in the statement of net loss and comprehensive loss. As at June 30, 2025, the fair value of the Silver Stream derivative liability is US$44,730,000 ($61,027,000). The fair value of the Silver Stream derivative liability as at December 31, 2024 was US$23,917,000 ($34,414,000), which is comprised of the Silver Stream obligation fair value of US$27,707,000 ($39,867,000) less the Advance Payment receivable fair value of US$3,790,000 ($5,453,000).

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

8. SILVER STREAM DERIVATIVE LIABILITY (continued)

9.  ACCOUNTS PAYABLE AND ACCRUED LIABILITIES

10.  FLOW-THROUGH SHARE PREMIUM LIABILITY

The following is a continuity schedule of the liability portion of the Company’s flow-through share issuances:

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

10. FLOW-THROUGH SHARE PREMIUM LIABILITY (continued)

As at June 30, 2025, the Company had $1,300,000 (December 31, 2024 - $4,197,000) of unspent flow-through expenditure commitments, which is required to be spent by December 31, 2025.

11. SHARE CAPITAL

a) Authorized

Unlimited number of common shares with no par value.

Unlimited number of preferred shares with no par value.

b) Issued and Fully Paid

Common shares as at June 30, 2025: 1,083,331,543 (December 31, 2024 - 1,079,863,747).

Preferred shares as at June 30, 2025: nil (December 31, 2024 - nil).

c) Warrants

The movements in warrants during the six months ended June 30, 2025 and year ended December 31, 2024 are summarized as follows (Note 8):

The following table summarizes information about warrants outstanding as at June 30, 2025:

d) Stock Options

The Company has adopted a stock option plan that allows for the granting of stock options to Directors, Officers, employees, and certain consultants of the Company for up to 10% of the Company’s issued and outstanding common shares. Stock options granted under the plan may be subject to vesting provisions as determined by the Board of Directors.

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

11.  SHARE CAPITAL (continued)

The movements in stock options during the six months ended June 30, 2025 and year ended December 31, 2024 are summarized as follows:

The following table summarizes information about the stock options outstanding as at June 30, 2025:

During the six months ended June 30, 2025, there were 18,000,000 (year ended December 31, 2024 - 26,907,500) stock options granted with an aggregate fair value at the date of grant of $1,123,897 (year ended December 31, 2024 - $1,500,715). As at June 30, 2025, 19,977,000 (year ended December 31, 2024 - 23,760,625) stock options remain unvested with an aggregate grant date fair value of $1,209,575 (December 31, 2024 - $1,503,560).

Certain stock options granted were directly attributable to exploration and evaluation expenditures on mineral properties and were therefore capitalized to mineral properties. In addition, certain stock options were subject to vesting provisions. These two factors result in differences between the aggregate fair value of stock options granted and total share-based payments expensed during the periods.

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

11.  SHARE CAPITAL (continued)

For the six months ended June 30, 2025, share-based payments expense is comprised of stock options for $828,528, restricted share units (“RSUs”) for $373,735, deferred share units (“DSUs”) for $34,491, and performance share units (“PSUs”) for $255,706, which are classified within the financial statements as follows:

The grant date fair value of the stock options granted in the period has been estimated using the Black-Scholes option pricing model with the following weighted average assumptions:

e) Restricted Share Units

During the six months ended June 30, 2025, the Company granted 7,756,956 (year ended December 31,2024 - 8,422,115) RSUs under its share-based compensation plan to the Company’s executive officers and management as part of the Company’s long-term incentive plan (“LTIP”). Unless otherwise stated, the awards typically have a graded vesting schedule over a three-year period and will be settled in equity upon vesting.

During the six months ended June 30, 2025, the Company issued 1,194,796 (2024 - 223,334) common shares pursuant to the exercise of RSUs for an aggregate settlement value of $135,190 (2024 - $73,090).

The associated compensation cost, which is based on the underlying share price on the date of grant, is recorded as share-based payments expense against share-based payment reserve.

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

11.  SHARE CAPITAL (continued)

The following table summarizes the changes in RSU’s for the six months ended June 30, 2025 and year ended December 31, 2024:

f) Deferred Share Units

During the six months ended June 30, 2025, the Company granted 400,000 (year ended December 31, 2024 - 400,000) DSUs under its share-based compensation plan to a director as part of the Company’s LTIP. DSUs have a graded vesting schedule over an 18-month period and will be settled in equity upon vesting.

The associated compensation cost, which is based on the underlying share price on the date of grant, is recorded as share-based payments expense against share-based payment reserve.

g) Performance Share Units

During the six months ended June 30, 2025, the Company granted 3,600,000 (year ended December 31, 2024 - 5,650,000) PSUs under the Plan to certain executives as part of the Company’s LTIP. The amount of shares ultimately to be issued will vary from a factor of 0 to 2 based on the number of PSUs granted, depending on the Company’s share performance as compared to the share performance of a selected group of peer companies.

The estimated value of the PSUs is determined at the grant date using a Monte Carlo simulation model. The model is based on several assumptions, including the share price volatility of the Company’s stock, as well as the volatility of the selected group of peer companies and the correlation of returns between the peer group and the Company.

During the six months ended June 30, 2025, the Company issued 455,000 (2024 - Nil) common shares pursuant to the settlement of PSUs for an aggregate value of $108,000 (2024 - $Nil).

FIRST MINING GOLD CORP.  

NOTES TO THE CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS 

11.  SHARE CAPITAL (continued)

The following table summarizes the changes in PSUs for the six months ended June 30, 2025 and year ended December 31, 2024:

Prior to vesting, the Company's PSUs are subject to a market-based performance condition, measured by the Company's relative total shareholder return performance against a defined peer group over a three-year period. Accordingly, the PSUs issued during the year ended December 31, 2022, which vested during the six months ended June 30, 2025, were evaluated against the performance condition. Following this evaluation, the number of PSUs that ultimately vested was lower than estimated at initial recognition, resulting in a reversal of $180,000 of previously recognized expense.

12.  OPERATING EXPENSES

Operating expenses by nature, which map to the Company’s functional operating expense categories presented in the consolidated statements of net loss and comprehensive loss, are as follows: