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UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C.
20549

FORM 40-F/A

[   ]     REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THESECURITIES EXCHANGE ACT OF 1934

OR

[X]     ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OFTHE SECURITIES EXCHANGE ACT OF 1934

|For the fiscal year ended December 31, 2016 | Commission File Number 000-55607
|------------------------------------------- | --------------------------------

FIRST MINING FINANCE CORP.(Exact name of registrant as specified in its charter)

|British Columbia, Canada        | 1040                         | Not Applicable        
|------------------------------- | ---------------------------- | ----------------------
|(Province or other jurisdiction | (Primary Standard Industrial | (I.R.S. Employer      
|of incorporation or             | Classification Code Number)  | Identification Number)
|organization)                   |                              |                       

Suite 1805  925 West Georgia Street,Vancouver,
British Columbia V6C 3L2, Canada(604) 688-3033(Address and telephone number of Registrants principal executive
offices)

National Registered Agents, Inc.1090 Vermont
Avenue N.W., Suite 910Washington D.C. 20005(202)
371-8090(Name, address (including zip code) and telephone
number (including area code) of agent for service in the United States)

---------------------

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Securities to be registered pursuant to Section 12(b) of the
Act:

|Title of each class: | Name of exchange on which registered:
|-------------------- | -------------------------------------
|None                 | None                                 

Securities registered pursuant to Section 12(g) of the Act:
Common Shares, no par value

Securities for which there is a reporting obligation pursuant
to Section 15(d) of the Act: None

For annual reports, indicate by check mark the information
filed with this Form.

[X] Annual information form     [X] Audited
annual financial statements

Indicate the number of outstanding shares of each of the
issuers classes of capital or common stock as of the close of the period
covered by the annual report. 539,439,736

Indicate by check mark whether the Registrant (1) has filed all
reports required to be filed by Section 13 or 15(d) of the Exchange Act during
the preceding 12 months (or for such shorter period that the Registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

[X] Yes     [   ] No

Indicate by check mark whether the registrant has submitted
electronically and posted on its corporate Web site, if any, every Interactive
Data File required to be submitted and posted pursuant to Rule 405 of Regulation
S-T (§232.405 of this chapter) during the preceding 12 months (or for such
shorter period that the Registrant was required to submit and post such files).

[   ] Yes     [X] No

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EXPLANATORY NOTE

First Mining Finance Corp. (the “Company”) is filing this Amendment No. 1 on Form 40-F/A (“Amendment No. 1”) to the Company’s Annual Report on Form 40-F, dated April 19, 2017 (the “Original Form 40-F”), for the sole purpose of including the Company’s independent auditors Audit Opinion, which is dated March 27, 2017, within the consolidated annual financial statements for the years ended December 31, 2016 and 2015.

Except as set forth above, this Amendment No. 1 does not modify or update any of the disclosures in the Original Form 40-F. This Amendment No. 1 speaks as of the time of filing the Original Form 40-F, does not reflect events that may have occurred subsequent to such filing, and does not modify or update in any way disclosures made in the Original Form 40-F.

First Mining Finance Corp. (the Company or the Registrant)
is a Canadian issuer eligible, pursuant to Section 13 of the Securities Exchange
Act, to file its annual report on Form 40-F pursuant to the multi-jurisdictional
disclosure system of the Exchange Act. The Company is a foreign private issuer
as defined in Rule 3b-4 under the Exchange Act. Equity securities of the Company
are accordingly exempt from Sections 14(a), 14(b), 14(c), 14(f) and 16 of the
Exchange Act pursuant to Rule 3a12-3.

FORWARD-LOOKING STATEMENTS

This annual report on Form 40-F and the exhibits attached
hereto contain forward-looking statements within the meaning of the United
States Private Securities Litigation Reform Act of 1995 and forward-looking
information within the meaning of applicable Canadian securities legislation.
Forward-looking statements, which are all statements other than statements of
historical fact, include, but are not limited to, statements with respect to the
future price of commodities, the estimation of mineral reserves and mineral
resources, the realization of mineral reserve estimates, the timing and amount
of estimated future production, costs of production, reserve determination and
reserve conversion rates. Generally, these forward-looking statements can be
identified by the use of forward-looking terminology such as plans, expects
or does not expect, is expected, budget, scheduled, estimates,
forecasts, intends, anticipates or does not anticipate, or believes,
or variations of such words and phrases or statements that certain actions,
events or results may, could, would, might or will be taken, occur
or be achieved. Forward-looking statements are subject to known and unknown
risks, uncertainties and other factors that may cause the actual results, level
of activity, performance or achievements of the Company to be materially
different from those expressed or implied by such forward-looking statements,
including but not limited to: fluctuations in the price of commodities; risks
related to mining and exploration operations including risks related to
fluctuations in the price of the primary commodities mined at such operations,
actual results of mining and exploration activities, economic and political
risks of the jurisdictions in which the mining and exploration operations are
located, changes in project parameters as plans continue to be refined; and
differences in the interpretation or application of tax laws and regulations; as
well as those factors discussed in the section entitled Risks that can affect
our business in the Companys annual information form (the AIF) for the
financial year ended December 31, 2016. Forward-looking statements are based on
assumptions management believes to be reasonable, including but not limited to:
no material adverse change in the market price of commodities, that the mining
and exploration operations will operate and the mining projects will be
completed in accordance with their public statements and achieve their stated
production outcomes, and such other assumptions and factors as set out herein.
Although the Company has attempted to identify important factors that could
cause actual results to differ materially from those contained in
forward-looking statements, there may be other factors that cause results not to
be as anticipated, estimated or intended. There can be no assurance that
forward-looking statements will prove to be accurate. Accordingly, readers
should not place undue reliance on forward-looking statements. The
forward-looking statements and forward-looking information contained or
incorporated by reference in this annual report on Form 40-F are included for
the purpose of providing investors with information to assist them in
understanding the Companys expected financial and operational performance and may not be
appropriate for other purposes. The Company does not undertake to update any
forward-looking statements that are included or incorporated by reference
herein, except in accordance with applicable securities laws.

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NOTE TO UNITED STATES READERS  DIFFERENCESIN
UNITED STATES AND CANADIAN REPORTING PRACTICES

The Company is permitted, under a multi-jurisdictional
disclosure system adopted by the United States, to prepare this annual report on
Form 40-F in accordance with Canadian disclosure requirements, which are
different from those of the United States. The Company prepares its financial
statements (the Audited Financial Statements) in accordance with International
Financial Reporting Standards as issued by the International Accounting
Standards Board.

The AIF filed as Exhibit 99.1 to this annual report on Form
40-F has been prepared in accordance with the requirements of the securities
laws in effect in Canada, which differ from the requirements of United States
securities laws. The terms mineral reserve, proven mineral reserve and
probable mineral reserve are Canadian mining terms as defined in accordance
with Canadian National Instrument 43-101  Standards of Disclosure for Mineral
Projects (NI 43-101) and the Canadian Institute of Mining, Metallurgy and
Petroleum (the CIM) CIM Definition Standards on Mineral Resources and Mineral
Reserves, adopted by the CIM Council, as amended. These definitions differ from
the definitions in the United States Securities and Exchange Commission (SEC)
Industry Guide 7 (SEC Industry Guide 7) under the United States Securities Act
of 1933, as amended. Under SEC Industry Guide 7 standards, a final or
bankable feasibility study is required to report reserves, the three-year
historical average price is used in any reserve or cash flow analysis to
designate reserves and the primary environmental analysis or report must be
filed with the appropriate governmental authority.

In addition, the terms mineral resource, measured mineral
resource, indicated mineral resource and inferred mineral resource are
defined in and required to be disclosed by NI 43-101; however, these terms are
not defined terms under SEC Industry Guide 7 and are normally not permitted to
be used in reports and registration statements filed with the SEC. Investors are
cautioned not to assume that any part or all of mineral deposits in these
categories will ever be converted into reserves. Inferred mineral resources
have a great amount of uncertainty as to their existence and as to their
economic and legal feasibility. It cannot be assumed that all or any part of an
inferred mineral resource will ever be upgraded to a higher category. Under
Canadian rules, estimates of inferred mineral resources may not form the basis
of feasibility or pre-feasibility studies, except in rare cases. Investors are
cautioned not to assume that all or any part of an inferred mineral resource
exists or is economically or legally mineable. Disclosure of contained ounces
in a resource is permitted disclosure under Canadian regulations; however, the
SEC normally only permits issuers to report mineralization that does not
constitute reserves by SEC standards as in place tonnage and grade without
reference to unit measures.

Accordingly, information contained in this annual report on
Form 40-F and the documents incorporated by reference herein containing
descriptions of the Companys mineral deposits may not be comparable to similar
information made public by U.S. companies subject to the reporting and disclosure requirements under the United States federal
securities laws and the rules and regulations thereunder.

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CURRENCY

Unless otherwise indicated, all dollar amounts in this annual
report on Form 40-F are in Canadian dollars. The functional currency of the
Company, the parent entity, is the Canadian dollar and for the Mexican and US
subsidiaries, the functional currency is the United States dollar. The financial
statement presentation currency is the Canadian dollar. The expenditures of our
operations where incurred in currencies other than Canadian dollars are
translated at the exchange rates in effect at the date of the underlying
transactions. Differences arising from these foreign currency transactions are
recorded in the consolidated statement of net loss.

ANNUAL INFORMATION FORM

The AIF is filed as Exhibit 99.1 to, and incorporated by
reference in, this annual report on Form 40-F.

AUDITED ANNUAL FINANCIAL STATEMENTS

The Audited Financial Statements for the year ended December
31, 2016, including the report of the independent registered public accounting
firm with respect thereto, is filed as Exhibit 99.2 to, and incorporated by
reference in, this annual report on Form 40-F.

MANAGEMENTS DISCUSSION AND ANALYSIS

The Companys managements discussion and analysis of results
of operations and financial condition for the year ended December 31, 2016 is
filed as Exhibit 99.3 to, and incorporated by reference in, this annual report
on Form 40-F.

CERTIFICATIONS

See Exhibits 99.4, 99.5, 99.6 and 99.7, which are included as
Exhibits to this annual report on Form 40-F.

DISCLOSURE CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

At the end of the period covered by this annual report on Form
40-F, an evaluation was carried out under the supervision of, and with the
participation of, the Companys management, including the Chief Executive
Officer (CEO) and Chief Financial Officer (CFO), of the effectiveness of the
Companys disclosure controls and procedures (as defined in Rule 13a  15(e) and
Rule 15d  15(e) under the Exchange Act). Based upon the results of that
evaluation, the CEO and the CFO have concluded that as of the end of the period
covered by this annual report on Form 40-F, the Companys disclosure controls
and procedures were effective. Disclosure controls and procedures include
controls and other procedures that are designed to ensure that (i) information required to be disclosed by the
Company in reports that it files or submits to the SEC under the Exchange Act is
recorded, processed, summarized and reported within the appropriate time periods
specified in applicable rules and forms and (ii) information required to be
disclosed by the Company in reports filed under the Exchange Act is accumulated
and communicated to the Companys management, including the CEO and CFO, as
appropriate, to allow for accurate and timely decisions regarding required
disclosure.

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Managements Report on Internal Control over Financial
Reporting

The Companys management, with the participation of the CEO and
CFO, is responsible for establishing and maintaining adequate internal control
over financial reporting as defined in Rules 13a-15(f) and 15d-15(f) under the
Exchange Act. The Companys internal control over financial reporting is a
process designed to provide reasonable assurance regarding the reliability of
financial reporting and the preparation and fair presentation of financial
statements for external purposes in accordance with International Financial
Reporting Standards as issued by the International Accounting Standards Board.
The Companys internal control over financial reporting includes policies and
procedures that:

| |  | maintain records that accurately and fairly reflect, in
      reasonable detail, the transactions and dispositions of assets of the
      Company;                                                                                                    
| | - | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| |  | provide reasonable assurance that transactions are
      recorded as necessary for preparation of financial statements in
      accordance with IFRS;                                                                                                 
| |  | provide reasonable assurance that the Companys receipts
      and expenditures are made only in accordance with authorizations of
      management and the Companys Directors; and                                                                  
| |  | provide reasonable assurance regarding prevention or
      timely detection of unauthorized acquisition, use, or disposition of the
      Companys assets that could have a material effect on the Companys
      consolidated financial statements.

Because of its inherent limitations, the Companys internal
control over financial reporting may not prevent or detect misstatements.
Additionally, projections of any evaluation of effectiveness to future periods
are subject to the risk that controls may become inadequate because of changes
in conditions, or that the degree of compliance with the policies or procedures
may deteriorate.

Management assessed the effectiveness of the Companys internal
control over financial reporting as of December 31, 2016, based on the criteria
set forth in Internal Control  Integrated Framework (2013) issued by the
Committee of Sponsoring Organizations of the Treadway Commission. This
evaluation included review of the documentation of controls, evaluation of the
design effectiveness of controls, testing of the operating effectiveness of
controls and a conclusion on this evaluation. Based on this evaluation,
management has concluded that the Companys internal control over financial
reporting was effective and no material weakness was identified as of December
31, 2016.

Attestation Report of the Registered Public Accounting
Firm

This annual report does not include an attestation report of
the Companys registered public accounting firm regarding internal control over
financial reporting due to a transition period established by rules of the Securities and Exchange Commission
for newly public companies.

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Changes in Internal Control over Financial Reporting

During the period covered by this annual report on Form 40-F,
no change occurred in the Companys internal control over financial reporting
that has materially affected, or is reasonably likely to materially affect, the
Companys internal control over financial reporting.

Limitations of Controls and Procedures

The Companys management, including the CEO and CFO, does not
expect that its disclosure controls and procedures or internal controls and
procedures will prevent all error and all fraud. A control system, no matter how
well conceived and operated, can provide only reasonable, not absolute,
assurance that the objectives of the control system are met. Further, the design
of a control system must reflect the fact that there are resource constraints,
and the benefits of controls must be considered relative to their costs. Because
of the inherent limitations in all control systems, no evaluation of controls
can provide absolute assurance that all control issues and instances of fraud,
if any, within the Company have been detected. These inherent limitations
include the realities that judgments in decision-making can be faulty, and that
breakdowns can occur because of simple error or mistake. Additionally, controls
can be circumvented by the individual acts of some persons, by collusion of two
or more people, or by management override of the control. The design of any
system of controls also is based in part upon certain assumptions about the
likelihood of future events, and there can be no assurance that any design will
succeed in achieving its stated goals under all potential future conditions;
over time, control may become inadequate because of changes in conditions, or
the degree of compliance with the policies or procedures may deteriorate.
Because of the inherent limitations in a cost-effective control system,
misstatements due to error or fraud may occur and not be detected.

AUDIT COMMITTEE

Audit Committee

The Companys board of directors has a separately designated
standing audit committee established in accordance with section 3(a)(58)(A) of
the Exchange Act. The members of the Companys audit committee are identified on
pages 93 to 95 of the AIF, filed as Exhibit 99.1 and incorporated by reference
herein. In the opinion of the Companys board of directors, all members of the
audit committee are independent (as determined under Rule 10A-3 of the Exchange
Act and the rules of the New York Stock Exchange) and are financially literate.

Audit Committee Financial Expert

The Companys board of directors has determined that Raymond
Polman is the audit committee financial expert, in that he has an understanding
of generally accepted accounting principles and financial statements; is able to
assess the general application of accounting principles, including, in
connection with the accounting for estimates, accruals and reserves. The
financial expert has experience preparing, auditing, analyzing or evaluating
financial statements that entail accounting issues of equal breadth and complexity to the
Companys financial statements (or actively supervising another person who did
so). The financial expert also has an understanding of internal controls and
procedures for financial reporting and an understanding of audit committee
functions.

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CODE OF ETHICS

The Company has adopted a written Code of Business Conduct and
Ethics. A copy of this code is available on the Companys website at
http://www.firstminingfinance.com or to any person without charge, by
written request addressed to: First Mining Finance Corp., Attention: Corporate
Secretary, Suite 1805  925 West Georgia Street, Vancouver, British Columbia V6C
3L2, Canada 1.844.306.8827, or by email (info@firstminingfinance.com).

PRINCIPAL ACCOUNTANT FEES AND SERVICES

BDO Canada LLP acted as the Companys Independent Registered
Public Accounting Firm for the financial years ended December 31, 2016 and
December 31, 2015. The following table sets out the total amount billed to the
Company by BDO Canada LLP, Independent Registered Public Accounting Firm and its
affiliates, for professional services performed in each of the years ended
December 31, 2016 and December 31, 2015, respectively, in Canadian dollars.

|Category           |  | Year ended December 31, 2016 |         | Year ended December 31, 2015
|------------------ |  | ---------------------------- | ------- | ----------------------------
|Audit Fees         |  | $                            | 131,750 |                             
|Audit Related Fees |  | $                            | -       |                             
|Tax Fees           |  | $                            | 34,714  |                             
|All Other Fees     |  | $                            | -       |                             

The Audit Fees relate to the audit of the annual consolidated
financial statements of the Company, and review of the interim condensed
consolidated financial statements for the years presented. The Audit Related
Fees in 2015 relate to the auditors consent, for procedures performed with
respect to information circulars and pro-forma financial statements, and formed
part of several acquisition transactions. The Tax Fees relate to tax compliance
services in Mexico and the US.

AUDIT COMMITTEE PRE-APPROVAL POLICIES AND PROCEDURES

See Exhibit 99.25 for the Companys Audit Committee Charter,
incorporated by reference in this annual report on Form 40-F.

OFF-BALANCE SHEET ARRANGEMENTS

The Company does not have any off-balance sheet arrangements
that have or are reasonably likely to have a current or future effect on its
financial condition, changes in financial condition, revenues or expenses,
results of operations, liquidity, capital expenditures or capital resources that
is material to investors, or relationships with unconsolidated special purpose
entities.

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TABULAR DISCLOSURE OF CONTRACTUAL OBLIGATIONS

The information provided under the heading Managements
Discussion and Analysis  Financial Instruments  Liquidity Risk contained in
Exhibit 99.3 as filed with this annual report on Form 40-F contains the
Companys disclosure of contractual obligations and is incorporated by reference
herein.

UNDERTAKINGS

The Company undertakes to make available, in person or by
telephone, representatives to respond to inquiries made by the SEC staff, and to
furnish promptly, when requested to do so by the SEC staff, information relating
to: the securities registered pursuant to Form 40-F; the securities in relation
to which the obligation to file an annual report on Form 40-F arises; or
transactions in said securities.

CONSENT TO SERVICE OF PROCESS

The Company filed an Appointment of Agent for Service of
Process and Undertaking on Form F-X with respect to the class of securities in
relation to which the obligation to file this annual report on Form 40-F arises.

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EXHIBIT INDEX

|Exhibit | Description                                                                                                                                                                               
|------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|        |                                                                                                                                                                                           
|99.1    | Annual Information Form of the Company for the year ended
      December 31, 2016                                                                                                         
|        |                                                                                                                                                                                           
|99.2    | Audited consolidated financial statements and related
      audit reports of the Company, for the year ended December 31, 2016 are
      exhibits to and form a part of this annual report
|        |                                                                                                                                                                                           
|99.3    | Managements Discussion and Analysis for the year ended
      December 31, 2016                                                                                                           
|        |                                                                                                                                                                                           
|99.4    | CEO Certification pursuant to Rule 13a-14(a) or 15d-14(a)
      of the Securities Exchange Act of 1934, as adopted pursuant to Section 302
      of the Sarbanes- Oxley Act of 2002       
|        |                                                                                                                                                                                           
|99.5    | CFO Certification pursuant to Rule 13a-14(a) or 15d-14(a)
      of the Securities Exchange Act of 1934, as adopted pursuant to Section 302
      of the Sarbanes- Oxley Act of 2002       
|        |                                                                                                                                                                                           
|99.6    | CEO Certification pursuant to 18 U.S.C. Section 1350, as
      adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002                                                          
|        |                                                                                                                                                                                           
|99.7    | CFO Certification pursuant to 18 U.S.C. Section 1350, as
      adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002                                                          
|        |                                                                                                                                                                                           
|99.8    | Consent of Dr. Adrian Dance, Ph.D., P.Eng., of SRK
      Consulting (Canada) Inc.                                                                                                         
|        |                                                                                                                                                                                           
|99.9    | Consent of Dr. Gilles Arseneau, Ph.D., P.Geo., of SRK
      Consulting (Canada) Inc.                                                                                                      
|        |                                                                                                                                                                                           
|99.10   | Consent of John F. Duncan, P.Eng., of SRK Consulting
      (Canada) Inc.                                                                                                                  
|        |                                                                                                                                                                                           
|99.11   | Consent of Christopher Elliot, FAusIMM, of SRK Consulting
      (Canada) Inc.                                                                                                             
|        |                                                                                                                                                                                           
|99.12   | Consent of Mark Liskowich, P.Geo., of SRK Consulting
      (Canada) Inc.                                                                                                                  
|        |                                                                                                                                                                                           
|99.13   | Consent of Michael Royle, M.App.Sci., P.Geo., of SRK
      Consulting (Canada) Inc.                                                                                                       
|        |                                                                                                                                                                                           
|99.14   | Consent of Bruce Murphy, P.Eng., FSAIMM, of SRK
      Consulting (Canada) Inc.                                                                                                            
|        |                                                                                                                                                                                           
|99.15   | Consent of Dr. Ewoud Maritz Rykaart, Ph.D., P.Eng., of
      SRK Consulting (Canada) Inc.                                                                                                 

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|99.16 | Consent of Dino
      Pilotto, P.Eng., of JDS Energy & Mining Inc.                          
|----- | --------------------------------------------------------------------------------------------
|      |                                                                                             
|99.17 | Consent of Todd
      McCracken, P.Geo., of WSP Canada Inc.                                 
|      |                                                                                             
|99.18 | Consent of Mark
      Drabble, B.App.Sci (Geology), MAIG, MAusIMM, of Optiro Pty Limited    
|      |                                                                                             
|99.19 | Consent of Kahan
      Cervoj, B.App.Sci (Geology), MAIG, MAusIMM, of Optiro Pty Limited    
|      |                                                                                             
|99.20 | Consent of B.
      Terrence Hennessey, P.Geo., of Micon International Limited              
|      |                                                                                             
|99.21 | Consent of Alan J.
      San Martin, MAusIMM(CP), of Micon International Limited            
|      |                                                                                             
|99.22 | Consent of Sam J.
      Shoemaker, Jr., B.Sc., Regd Mem SME, of Micon International Limited
|      |                                                                                             
|99.23 | Consent of Michael
      P. Cullen, M.Sc., P.Geo., of Mercator Geological Services Limited  
|      |                                                                                             
|99.24 | Consent of BDO
      Canada LLP, Independent Registered Public Accounting Firm              
|      |                                                                                             
|99.25 | Audit Committee
      Charter of the Company                                                

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SIGNATURES

Pursuant to the requirements of the Exchange Act, the Company certifies that it meets all of the requirements for filing on Form 40-F and has duly caused this Amendment No. 1 to the Annual Report to be signed on its behalf by the undersigned, thereto duly authorized.

Date: September 22, 2017

FIRST MINING FINANCE CORP.

By:
    /s/ Andrew MarshallAndrew MarshallChief Financial Officer


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