First Mining Reports Updated Gold Resource Estimate for the Cameron Gold Project in Northwestern Ontario

VANCOUVER, BRITISH COLUMBIA--(Marketwired - Mar 22, 2017) - First Mining Finance Corp. ("First Mining" or the "Company") (TSX VENTURE:FF)(OTCQX:FFMGF)(FRANKFURT:FMG) is pleased to announce the release of an updated mineral resource estimate for its Cameron Gold Project ("Cameron" or the "Project") located near the town of Sioux Narrows in northwestern Ontario. First Mining acquired the Cameron Gold Project on June 9, 2016 pursuant to its acquisition of a subsidiary of Chalice Gold Mines Ltd. ("Chalice") that held the Project.

The updated mineral resource estimate for Cameron was prepared by Optiro Pty Limited ("Optiro") of Perth, Australia and has an effective date of January 17, 2017. A technical report for this updated resource estimate entitled "Technical Report on the Cameron Gold Deposit, Ontario, Canada" ("the "Technical Report"), which was prepared in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101"), has been filed by the Company under its SEDAR profile at www.sedar.com, and is also available on the Company's website.

Highlights of the Cameron Deposit

• Pit constrained (0.55 g/t Au cut-off) Measured and Indicated mineral resources of 3.5 million tonnes at 2.45 grams per tonne or 274,000 ounces of gold,
• Pit constrained (0.55 g/t Au cut-off) Inferred mineral resources of 35,000 tonnes at 2.45 grams per tonne or 3,000 ounces of gold,
• Underground (2.00 g/t Au cut-off) Measured and Indicated mineral resources of 2.0 million tonnes at 2.90 grams per tonne or 190,000 ounces of gold, and
• Underground (2.00 g/t Au cut-off) Inferred mineral resources of 6.5 million tonnes at 2.54 grams per tonne or 530,000 ounces of gold.

This latest mineral resource estimate replaces the previous resource estimate which defined the global in-situ resources at the property. Later this year, First Mining expects to commence a 9,000 metre drilling campaign at Cameron. The goal of the proposed drilling campaign is to upgrade the existing Inferred mineral resources into the Measured and Indicated categories and to drill exploration targets that lie outside of the main Cameron resource area. This latest mineral resource estimate for Cameron does not include mineralized material from the Dogpaw and Dubenski areas. These areas contain historic resources, and the Company plans to conduct additional exploration activities at a later date to define a current resource for these areas.

Patrick Donnelly, President of First Mining stated, "This updated mineral resource estimate for Cameron confirms our internal estimates from the Company's due diligence review of the Project regarding the amount of recoverable gold that is hosted at Cameron. What is especially compelling is that this Project consists of a very large land package that has the potential to host additional gold mineralization. We anticipate that our proposed 9,000 metre drilling campaign should further confirm our expectations that Cameron could become a gold project of significant merit, with further upside at several of the satellite deposits."

Table 1: Open-Pit and Underground Mineral Resource Estimates at Cameron effective January 17, 2017

• The mineral resource estimate is classified as Measured, Indicated and Inferred mineral resources.
• 2014 CIM Definition Standards were followed for classification of mineral resources.
• The mineral resource has been estimated using a gold price of US$1,350/oz.
• The mineral resource was estimated using a block model. Three dimensional wireframes were generated using geological information. The ordinary kriging estimation method was used to interpolate grades into blocks. Blocks were sub-blocked to more accurately reflect the volume of the wireframes.
• Mineral resources that are not mineral reserves do not have demonstrated economic viability. There is currently insufficient exploration to define these Inferred mineral resources as Indicated or Measured mineral resources and it is uncertain if further exploration will result in upgrading them to an Indicated or Measured mineral resource category.
• Numbers may not add due to rounding.

The Cameron Gold deposit is a shear hosted gold deposit within a structurally complex belt of arcuate greenstones and felsic intrusive bodies. The regional controls are well documented in terms of the major structural elements and their interactions. The local geology has been mapped at the surface in trenches and outcrops and also in underground drift development. There has been extensive drilling coverage of the deposit from surface and underground and the information used in developing the estimate is exclusively from high quality diamond drilling samples and logging.

Gold is associated with disseminated pyrite with high sulphide concentration generally corresponding with higher gold grades. The mineralization is open at depth and along strike to the northwest with potential to expand the mineral resource in these directions.

The mineral resource estimate for Cameron has been updated using an additional 30,000 samples which, combined with the re-logging of approximately 771 diamond holes (103,000 metres), has increased the confidence of the geological and mineralisation interpretations. The definition of grade domains and continuity is considered to be robust and with greater confidence at a more local scale than previous estimates due to the much greater number of samples.

The interpretation of the deposit scale geological model was done in a collaborative manner, with the Cameron site geological team (who were responsible for the re-logging of the drilling) involved in the interpretation of sectional and wireframe interpretations of the geology and mineralization. These interpretations were used by Optiro as a guide to compile the 3D geological model using Leapfrog Geo 3D software. The geological modelling process was iterative with discussions and amendments made in order to validate the definition of the lithological and structural elements into an integrated model.

With respect to the tonnage and metal risk, the volumetric controls of thickness and extent of the mineralized domains are considered to be robust and well constrained by the geological interpretations. The density assignment is based on the results of 1,202 measurements that were grouped by lithology. The average values assigned are considered to be representative of the lithologies present.

A kriging neighbourhood analysis (KNA) was undertaken to determine the optimal block size, to test for the optimal search ellipse orientation and dimensions and to test the minimum and maximum numbers of samples to be used for grade estimation. This analysis used the variogram parameters and an iterative series of estimates with varying block size, search and sample number, using kriging efficiency (KE) and slope of regression (slope) values to provide a metric of estimation performance.

Discrete areas that represent well (4 to 15 m centred sampling), moderately (15 to 50 m centred sampling) and poorly (>50 m sampling) sampled areas were identified for each of the significant lodes (FW1, MID, Main and HW). The contrast in available sample density makes selection of the parent cell size and search strategy an exercise in compromise between efficiency in undertaking the estimate, reliability of the estimate and reflecting the known geology.

The mineral resources have been reported using two Au cut-off grades. The parts of the deposit considered amenable to open pit mining methods have been reported using a 0.55 g/t Au cut-off grade applied within a constraining Whittle open pit shell down to a depth of 235 metres below natural surface. Below this, the deposit has been reported at a 2.00 g/t Au cut-off grade, which is considered to be appropriate for underground mining using the longhole open stoping method. A gold price of US$1,350 and metallurgical recovery of 91.5% has been used. The parameters for the optimisation process and assumptions for open pit and underground mining are included in table 2.

Table 2: Cameron Open Pit and Underground Parameters

QUALIFIED PERSONS

Dr. Chris Osterman, P.Geo., CEO of First Mining, is a qualified person as defined by NI 43-101 and has reviewed and approved, and accepts responsibility for, the technical information contained within this press release. Mr. Mark Drabble, MAIG, MAusIMM, and Mr. Kahan Cervoj, MAIG, MAusIMM, Principal Consultants with Optiro Pty Ltd., are the authors of the Technical Report, and each of them is an independent "qualified person" within the meaning of NI 43-101.

Neither Mr. Drabble, Mr. Cervoj nor any associates employed by Optiro Pty Ltd. in the preparation of the Technical Report ("Consultants") have any beneficial interest in First Mining. These Consultants are not insiders, associates, or affiliates of First Mining. The results of this Technical Report are not dependent upon any prior agreements concerning the conclusions to be reached, nor are there any undisclosed understandings concerning any future business dealings between First Mining and the Consultants. The Consultants are paid a fee for their work in accordance with normal professional consulting practices.

ABOUT THE CAMERON PROJECT

The Cameron Gold Project was acquired by First Mining from Chalice on June 9, 2016. The project, which covers an area of over 44,853 hectares (110,835 acres), is located in northwestern Ontario, approximately 75 kilometres southeast of Kenora and approximately 30 kilometres southeast of the Township of Pickle Lake.

ABOUT FIRST MINING FINANCE CORP.

First Mining is a mineral property holding company whose principal business activity is to acquire high quality mineral assets with a focus in the Americas. The Company currently holds a portfolio of 25 mineral assets in Canada, Mexico and the United States with a focus on gold. Ultimately, the goal is to continue to increase its portfolio of mineral assets through acquisitions that are expected to be comprised of gold, silver, copper, lead, zinc and nickel.

ON BEHALF OF FIRST MINING FINANCE CORP.

Keith Neumeyer
Chairman

Cautionary Note Regarding Forward-Looking Statements

This news release includes certain "forward-looking information" and "forward-looking statements"(collectively "forward-looking statements") within the meaning of applicable Canadian and United States securities legislation including the United States Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, included herein, without limitation, statements relating the future operating or financial performance of the Company, are forward-looking statements.

Forward-looking statements are frequently, but not always, identified by words such as "expects", "anticipates", "believes", "intends", "estimates", "potential", "possible", and similar expressions, or statements that events, conditions, or results "will", "may", "could", or "should" occur or be achieved. Forward-looking statements in this news release relate to, among other things: commencement of expansion drilling at the Cameron project; the potential results of such drilling; any upgrade to, or expansion of, the resources on the Cameron project or the Dogpaw and Dubenski deposits; and the exploration potential and upside of the Cameron project. Actual future results may differ materially. There can be no assurance that such statements will prove to be accurate, and actual results and future events could differ materially from those anticipated in such statements. Forward-looking statements reflect the beliefs, opinions and projections on the date the statements are made and are based upon a number of assumptions and estimates that, while considered reasonable by the respective parties, are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies. Many factors, both known and unknown, could cause actual results, performance or achievements to be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-looking statements and the parties have made assumptions and estimates based on or related to many of these factors. Such factors include, without limitation, management's discretion to refocus its exploration efforts; fluctuations in the spot and forward price of gold, silver, base metals or certain other commodities; fluctuations in the currency markets (such as the Canadian dollar versus the U.S. dollar); changes in national and local government, legislation, taxation, controls, regulations and political or economic developments; risks and hazards associated with the business of mineral exploration, development and mining (including environmental hazards, industrial accidents, unusual or unexpected formations, pressures, cave-ins and flooding); the presence of laws and regulations that may impose restrictions on mining; employee relations; relationships with and claims by local communities and indigenous populations; availability and increasing costs associated with mining inputs and labour; the speculative nature of mineral exploration and development; results of exploration programs; accuracy of resource estimates; inability to meet future financing needs on acceptable terms; and title to properties. Readers should not place undue reliance on the forward-looking statements and information contained in this news release concerning these times. Except as required by law, First Mining does not assume any obligation to update the forward-looking statements of beliefs, opinions, projections, or other factors, should they change, except as required by law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Contact

First Mining Finance Corp.
Patrick Donnelly
President
604-639-8854
First Mining Finance Corp.
Derek Iwanaka
Vice President, Investor Relations
604-639-8824
www.firstminingfinance.com