McEwen Mining Continues to Expand Los Azules' Large, High-Grade, Mineral Resource

Tue Feb 5, 2013 4:30pm EST

* Reuters is not responsible for the content in this press release.

  TORONTO, ONTARIO, Feb 05 (MARKET WIRE) --
McEwen Mining Inc. (NYSE:MUX)(TSX:MUX) is pleased to announce an updated,
Canadian National Instrument 43-101 compliant ("NI 43-101") mineral
resource estimate for its 100% owned Los Azules Copper Project in San
Juan Province, Argentina. Most importantly, drilling has expanded
contained copper in the inferred resource category by 29% to 13.95
billion lbs. Contained copper in the indicated resource decreased
slightly to 4.45 billion lbs. The expanded resource incorporates 6,966
meters of new drilling from 10 additional holes. The resource remains
open laterally, to depth and along strike (to view cross-sections
displaying the resource click here). Los Azules is one of the world's
largest, undeveloped, high-grade, open pit copper projects which,
contains significant growth potential.

    Table 1. Los Azules Copper Project - Comparison of Previous and Current
Mineral Resource Estimates


============================================================================
                                        January 2013 Resource               
          June 2012 Resource Estimate      Estimate Update        % Change  
----------------------------------------------------------------------------
  Cut-off  Tonnage    Cu              Tonnage    Cu                         
   Grade   (million Grade    Cu lbs   (million Grade    Cu lbs    Contained 
   (Cu%)   tonnes)   (%)   (billions) tonnes)   (%)   (billions)   Cu lbs   
----------------------------------------------------------------------------
Indicated Resource                                                          
----------------------------------------------------------------------------
   0.35      323     0.65     4.64      310     0.65     4.45        -4%    
----------------------------------------------------------------------------
Inferred Resource                                                           
----------------------------------------------------------------------------
   0.35      948     0.52    10.82     1,302    0.49    13.95       +29%    
============================================================================
(i)Details for gold and silver resources are included in Table 2.           


    "Los Azules is a unique asset, in terms of size and grade, for McEwen
Mining. This year's exploration drilling has demonstrated that there is
significant potential to expand the resource well beyond our previous
understanding of the deposit," stated Rob McEwen, Chief Owner.

    Drilling this season represents the first time a meaningful amount of
deeper drilling has occurred at Los Azules. Prior to this year the
deepest drill hole was 650 meters. This season there has been a total of
6 holes that exceeded 700 meters. This deeper drilling has begun to
identify a potential parallel trend, west of the original Los Azules
ore-body. Copper mineralization discovered within this trend occurs near
surface and also at depth (down to 1,050 meters below surface). This is
significant because it may indicate that previous shallow drilling, which
makes up the majority of the Los Azules resource, failed to adequately
test the deeper potential of the deposit. As a result, many new
exploration targets have emerged.

    McEwen Mining has begun work on an updated Preliminary Economic
Assessment (PEA) which is expected to be completed in the third quarter
of this year. The updated PEA will be based on a significantly larger
mineral resource and will evaluate the possibility of increasing the
daily throughput. The PEA will also incorporate further metallurgical
studies currently being done on the possibility of producing copper
cathode instead of a concentrate and processing low grade mineralized
material not previously considered, via a heap leach. The advantage of
producing a copper cathode is that it would eliminate the contemplated
slurry pipeline through Chile and would reduce Argentina's export tax on
concentrate.

    This news release has been submitted by Andrew Elinesky, Vice President -
Argentina, for the Company.

    About Los Azules

    Los Azules is a large undeveloped copper porphyry system located in
western San Juan Province within a belt of porphyry copper deposits that
straddles the Chilean/Argentine border. This belt contains some of the
world's largest copper deposits, including Codelco's El Teniente and
Andina mines, Anglo American's Los Bronces mine, Antofagasta PLC's Los
Pelambres mine and Xstrata's El Pachon project, among others. Los Azules
is one of the world's largest, highest grade, undeveloped copper-porphyry
deposits not owned by a major base metal company.

    Table 2. Los Azules Mineral Resource Estimate

    In order to exhibit reasonable prospects for economic viability, the
mineral resource estimate has been contained within a conceptual open pit
shell generated using general technical and economic parameters that are
defined at the end of this news release. The base case cut-off grade of
0.35% Cu is highlighted in the table. 


============================================================================
                                           Au                Ag             
                                         Grade             Grade            
              Tonnage    Cu              (grams            (grams           
Cut-off Grade (million Grade    Cu lbs    per     Au Oz     per     Ag Oz   
    (Cu%)     tonnes)   (%)   (billions) tonne) (millions) tonne) (millions)
----------------------------------------------------------------------------
Indicated Resource                                                          
----------------------------------------------------------------------------
     0.15       414     0.55     5.04     0.06     0.83     1.8      23.6   
----------------------------------------------------------------------------
     0.20       397     0.57     4.97     0.06     0.80     1.8      22.6   
----------------------------------------------------------------------------
     0.25       369     0.59     4.84     0.06     0.76     1.8      21.1   
----------------------------------------------------------------------------
     0.30       338     0.62     4.65     0.07     0.72     1.8      19.6   
----------------------------------------------------------------------------
     0.35       310     0.65     4.45     0.07     0.68     1.8      18.3   
----------------------------------------------------------------------------
     0.40       283     0.68     4.22     0.07     0.63     1.9      16.9   
----------------------------------------------------------------------------
     0.45       254     0.71     3.95     0.07     0.57     1.9      15.4   
----------------------------------------------------------------------------
     0.50       225     0.74     3.64     0.07     0.52     1.9      13.8   
----------------------------------------------------------------------------
     0.55       195     0.77     3.30     0.07     0.46     1.9      12.1   
----------------------------------------------------------------------------
     0.60       165     0.80     2.92     0.07     0.40     1.9      10.2   
----------------------------------------------------------------------------
     0.65       134     0.85     2.49     0.08     0.33     1.9      8.2    
----------------------------------------------------------------------------
     0.70       105     0.89     2.07     0.08     0.26     1.9      6.5    
----------------------------------------------------------------------------
Inferred Resource                                                           
----------------------------------------------------------------------------
     0.15      3,378    0.34    25.33     0.04     4.84     1.7     181.4   
----------------------------------------------------------------------------
     0.20      2,890    0.37    23.44     0.05     4.35     1.7     159.8   
----------------------------------------------------------------------------
     0.25      2,318    0.40    20.61     0.05     3.71     1.8     134.9   
----------------------------------------------------------------------------
     0.30      1,774    0.44    17.32     0.05     3.01     1.9     108.9   
----------------------------------------------------------------------------
     0.35      1,302    0.49    13.95     0.06     2.34     2.0      83.3   
----------------------------------------------------------------------------
     0.40       914     0.53    10.76     0.06     1.72     2.1      60.8   
----------------------------------------------------------------------------
     0.45       622     0.59     8.03     0.06     1.21     2.1      42.8   
----------------------------------------------------------------------------
     0.50       422     0.64     5.96     0.06     0.85     2.2      29.7   
----------------------------------------------------------------------------
     0.55       290     0.69     4.43     0.06     0.60     2.2      20.6   
----------------------------------------------------------------------------
     0.60       201     0.75     3.31     0.07     0.42     2.3      14.5   
----------------------------------------------------------------------------
     0.65       143     0.80     2.51     0.07     0.31     2.3      10.5   
----------------------------------------------------------------------------
     0.70       103     0.84     1.91     0.07     0.22     2.3      7.6    
============================================================================
(i)   "Tonnes" is stated in metric and is equivalent to 2205 lbs.           
(ii)  Estimated contained metal values may be subject to rounding errors.   


    Details on the parameters of the resource estimate are as follows:


--  The resource estimation was based on data from 173 drill holes
    comprising a total length of 50,612 meters of drilling completed to the
    end of December 2012. 



--  There were a total of 23,178 individual samples selected for analysis.
    The samples were collected and analyzed in accordance with industry
    standards. Splits from the drill core samples were submitted to either
    Alex Stewart in Mendoza or ALS Chemex or ACME in Santiago, Chile for
    fire assay and ICP analysis. Accuracy of results is tested through the
    systematic inclusion of standards, blanks and check assays. 

--  The January 2013 mineral resource estimate for the Los Azules Copper
    Project was prepared under the direction of Robert Sim, P.Geo. of SIM
    Geological Inc. The mineral resource estimate uses drill hole sample
    assay results and the interpretation of a geologic model that relates to
    the spatial distribution of copper in the deposit. Interpolation
    characteristics were defined based on the geology, drill hole spacing
    and geostatistical analysis of the data. Block grade estimates were done
    using Ordinary Kriging (OK) with a nominal block size measuring 20
    meters long, 20 meters wide and 15 meters high. Resources are classified
    according to their proximity to sample data locations and are reported,
    as required under NI 43-101, according to the CIM Definition Standards
    for Mineral Resources and Mineral Reserves. 

--  Mineral resources, which are not mineral reserves, do not have
    demonstrated economic viability. 

--  The quantity and grade of reported Inferred resources are uncertain in
    nature and there has been insufficient exploration to classify these
    inferred resources as Indicated or Measured, and it is uncertain if
    further exploration will result in upgrading them to an Indicated or
    Measured category. 

--  As required under NI 43-101, reasonable prospects for economic viability
    of the mineral resources has been exhibited by the application of a
    resource limiting pit shell built about copper grades in the model using
    a projected metal price of US$2.75 per lb. Cu, mining costs of US$1.00
    per tonne, milling and G&A costs of US$4.25 per tonne, 100% recoveries
    and an average pit slope of 34 degrees. 


    About McEwen Mining (www.mcewenmining.com) 

    The goal of McEwen Mining is to qualify for inclusion in the S&P 500 by
2015 by creating a high growth, low-cost, mid-tier gold producer focused
in the Americas. McEwen Mining's principal assets consist of the San Jose
Mine in Santa Cruz, Argentina (49% interest); the El Gallo Complex in
Sinaloa, Mexico; the Gold Bar Project in Nevada, US; the Los Azules
Project in San Juan, Argentina and a large portfolio of exploration
properties in Argentina, Nevada and Mexico. 

    McEwen Mining has 296,024,859 shares issued and outstanding. Rob McEwen,
Chairman, President and Chief Owner, owns approximately 25% of the shares
of the Company. As of December 31, 2012, McEwen Mining had cash and
liquid assets of approximately US$70 million and is debt free.

    Technical Information:

    Robert Sim, P.Geo., who is a Qualified Person and independent of McEwen
Mining, each as defined by National Instrument 43-101 ("NI 43-101") has
reviewed and approved the technical content of this news release related
to the mineral resource estimate presented herein. Notwithstanding, Bruce
Davis, PhD, FAusIMM, who is a Qualified Person and independent of McEwen
Mining, as defined by NI 43-101 and responsible for the quality control
for the assaying of the Los Azules drill core has reviewed the assay
quality control information. All samples were collected in accordance
with industry standards. Splits from the drill core samples were
submitted to the ACME sample preparation laboratory in Mendoza,
Argentina, and then transferred to ACME's laboratory in Santiago, Chile
for fire assay and ICP analysis. Accuracy of results is tested through
the systematic inclusion of standards, blanks and check assays. The
mineral resource estimate referenced in this press release was prepared
in January 2013 by Robert Sim, P.Geo. and Bruce Davis, PhD, FAusIMM.

    For additional information about the Los Azules project see the Technical
Report titled "Los Azules Porphyry Copper Project, San Juan Province,
Argentina" dated August 1, 2012, with an effective date of June 15, 2012,
prepared by D. Ernest Winkler, P.Eng., Robert Sim, P.Geo., Bruce Davis,
PhD, FAusIMM and James K. Duff, P.Geo., all of whom are qualified persons
and all of whom are independent of McEwen Mining, each as defined by NI
43-101. The foregoing report is available under the Corporation's profile
on SEDAR (www.sedar.com).

    Cautionary Note to U.S. Investors:

    McEwen Mining reports its resource estimates in accordance with standards
of the Canadian Institute of Mining, Metallurgy and Petroleum referred to
in Canadian National Instrument 43-101 ("NI 43-101"). These standards are
different from the standards generally permitted in reports filed with
the SEC. Under NI 43-101, McEwen Mining reports measured, indicated and
inferred resources, measurements which are generally not permitted in
filings made with the SEC. According to Canadian NI 43-101 criteria, the
estimation of measured resources and indicated resources involve greater
uncertainty as to their economic feasibility than the estimation of
proven and probable reserves. Under SEC Industry Guide 7 criteria,
measured, indicated and inferred resources are considered Mineralized
Material. The SEC considers that in addition to greater uncertainty as to
the economic feasibility of Mineralized Material compared to proven and
probable reserves, there is also greater uncertainty as to the existence
of Mineralized Material. U.S. investors are cautioned not to assume that
measured or indicated resources will be converted into economically
mineable reserves. The estimation of inferred resources involves far
greater uncertainty as to their existence and economic viability than the
estimation of other categories of resources.

    Caution Concerning Forward-Looking Statements

    This press release contains certain forward-looking statements and
information, including "forward-looking statements" within the meaning of
the Private Securities Litigation Reform Act of 1995. The forward-looking
statements and information expressed, as at the date of this press
release, McEwen Mining Inc.'s (the "Company") estimates, forecasts,
projections, expectations or beliefs as to future events and results.
Forward-looking statements and information are necessarily based upon a
number of estimates and assumptions that, while considered reasonable by
management, are inherently subject to significant business, economic and
competitive uncertainties, risks and contingencies, and there can be no
assurance that such statements and information will prove to be accurate.
Therefore, actual results and future events could differ materially from
those anticipated in such statements and information. Risks and
uncertainties that could cause results or future events to differ
materially from current expectations expressed or implied by the
forward-looking statements and information include, but are not limited
to, risks related to the cost of transferring or otherwise allocating
funds between operating jurisdictions, factors associated with
fluctuations in the market price of precious metals, mining industry
risks, political, economic, social and security risks associated with
foreign operations, risks associated with the construction of mining
operations and commencement of production and the projected costs
thereof, risks related to litigation, property title, the state of the
capital markets, environmental risks and hazards, uncertainty as to
calculation of mineral resources and reserves and other risks. Readers
should not place undue reliance on forward-looking statements or
information included herein, which speak only as of the date hereof. The
Company undertakes no obligation to reissue or update forward-looking
statements or information as a result of new information or events after
the date hereof except as may be required by law. See McEwen Mining's
Annual Report on Form 10-K for the fiscal year ended December 31, 2011
and other filings with the Securities and Exchange Commission, under the
caption "Risk Factors", for additional information on risks,
uncertainties and other factors relating to the forward-looking
statements and information regarding the Company. All forward-looking
statements and information made in this news release are qualified by
this cautionary statement.

    To view Figure 1, please visit the following link:
http://media3.marketwire.com/docs/mux0205fig1.pdf.

    To view the cross-sections displaying the resource, please visit the
following link: http://media3.marketwire.com/docs/mux0205cs.pdf.

    The NYSE and TSX have not reviewed and do not accept responsibility for
the adequacy or accuracy of the contents of this news release, which has
been prepared by management of McEwen Mining Inc.

Contacts:
McEwen Mining Inc.
Jenya Meshcheryakova
Investor Relations`
(647) 258-0395 ext 410 or Toll Free: (866) 441-0690
(647) 258-0408 (FAX)

McEwen Mining Inc.
Mailing Address
181 Bay Street Suite 4750
Toronto, ON M5J 2T3
PO box 792
info@mcewenmining.com

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