Category: Silver / Gold

Osisko Intersects 185.2 Metres Averaging 1.97 g/t Au at South Barnat

Osisko Mining Corporation ("Osisko") (TSX: OSK)(FRANKFURT: EWX) is pleased to announce new results from the definition drill program currently under way at South Barnat, a separate gold mineralized zone located approximately 1200 metres northeast of the center of the Canadian Malartic deposit. Significant results include 1.97 g/t Au over 185.2 metres (BA08-3114) and 5.09 g/t Au over 61.5 metres (BA08-3110). Narrow zones of exceptional high-grade gold values were also encountered, including 224.0 g/t Au over 1.2m (BA08-3093) and 191.2 g/t Au over 1.5m (BA08-3116). Results from twenty-three new holes are tabled below:

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Hole No.      Section     From (m)      To (m)    Length (m)      Au g/t
------------------------------------------------------------------------
BA08-3092        200E       200.8       218.4          17.6         3.56
 Including                  215.3       216.4           1.1        41.90
BA08-3093        250E        97.1       173.5          76.4         5.70
 Including                  145.0       146.2           1.2        224.0
BA08-3093 Cut(i) 250E        97.1       173.5          76.4         2.66
BA08-3094        250E       289.0       325.0          36.0         1.60
 And                        362.5       457.0          94.5         0.83
BA08-3096        100E        15.8        73.0          57.2         1.54
BA08-3097        050E        32.0        84.5          52.5         2.11
BA08-3098        050E       129.0       170.3          41.3         1.31
BA08-3099        050E       130.0       178.5          48.5         1.93
BA08-3100        400E        17.0        75.2          58.2         1.31
 And                         98.0       123.0          25.0         1.45
 And                        170.0       240.2          70.2         2.25
 Including                  208.0       209.0           1.0        77.90
BA08-3102        150E       110.5       116.7           6.2         4.93
BA08-3104        300E        62.0        69.0           7.0         5.98
 And                        172.5       180.5           7.7         8.34
BA08-3105        200E        17.5        33.0          15.5         2.32
BA08-3106        200E       122.5       178.0          55.5         2.06
BA08-3107        200E       177.0       244.0          67.0         1.39
BA08-3110        300E        21.5        83.0          61.5         5.09
 Including                   26.0        27.0           1.0        54.30
 Including                   59.5        61.0           1.5        74.90
BA08-3111B       250E        14.5        42.1          27.6         0.97
BA08-3112        250E        18.0        27.0           9.0         1.98
BA08-3113        400E        63.2        95.0          31.8         4.89
 Including                   81.5        83.0           1.5        54.50
 And                        119.7       161.0          41.3         1.73
BA08-3114        600E        71.0       146.4          75.4         1.58
 And                        176.5       361.7         185.2         1.97
 Including                  346.0       361.7          17.2         6.85
BA08-3115        400E       161.1       292.5         131.4         1.22
BA08-3116        300E        20.5        56.5          36.0         9.43
 Including                   28.0        29.5           1.5        191.2
BA08-3116 Cut(i) 300E        20.5        56.5          36.0         2.71
BA08-3117        300E        13.9        36.0          22.1         1.63
BA08-3118        600E        10.2        11.5          30.4         1.45
BA08-3119        350E       193.0       260.0          67.0         1.15
------------------------------------------------------------------------
(i) Drill holes BA08-3093 and BA08-3116 include intervals cut to 30 g/t Au
    due to exceptionally high grade intervals intersected in the drill
    hole.

Drill hole BA08-3098 represents new gold mineralization intersected north of the main deposit. This zone will be investigated with further drilling. Drill hole BA08-3114 was lost in mineralized sediment and the extension of the mineralized zone will be drilled from the opposite azimuth.

Drill holes BA08-3091, BA08-3101, BA08-3103, BA08-3108 BA08-3109 and BA08-3120 did not intersect significant mineralization. The latter were mostly drilled north of the known mineralized zone. Drill hole BA08-3095H was lost at shallow depths and did not intersect mineralization. Drill holes BA08-3102, BA08-3104 and BA08-3118 intercepted historic mine workings and did not reach the intended target depths. Assay results for further holes at South Barnat are pending.

The definition drill program is focused on an 850 metre-long grid oriented northwest-southeast with drill sections spaced 50 metres apart. All holes on this grid are inclined 45 to 75 degrees to the northeast or southwest. True widths of the mineralized intersections reported above are 40 to 70 percent of the drilled intersections.

Drilling to date suggests that the minimum strike length of the South Barnat Zone is 850 metres with a true width between 20 and 160 metres. The mineralized zone is open along strike to the southeast, where it merges with the old East Malartic Mine. It extends to depths of 250 to 400 metres in the southeastern portion, where the system is still open at depth. Estimated depth in the northwestern third of the deposit is 130 to 200 metres.

Mineralization in the South Barnat Zone is located to the north and south of the old Barnat and East Malartic mine workings, largely along the southern edge of the Cadillac fault. The gold mineralization comprises multiple subvertical, tabular subzones hosted both in silicified greywackes of the Pontiac Group south of the fault contact and in schistose, carbonated and biotitic ultramafic rocks north of the fault contact. Porphyry dykes on both sides of the fault contain disseminated mineralization as well as late quartz veins containing visible gold. Gold mineralization in the South Barnat Zone likely extends to the east along the north and south walls of the past-producing East Malartic mine.

All NQ or HQ core assays reported above were obtained by standard 50 g fire assaying-AA finish or gravimetric finish at ALS Chemex laboratories in Val d'Or, Quebec. Reported weighted averages were calculated using a minimum of 0.50 g/t Au over successive maximum intervals of 20 metres with no upper cut-off of individual assays. Intersected drifts or lost core within mineralized intersections were incorporated as blank intervals.

Osisko Mining Corp. is currently evaluating the Canadian Malartic gold deposit and adjacent areas for a large-scale open pit, bulk-tonnage mining operation. The Company is well-funded with approximately $130 million on hand and is carrying out an aggressive definition drilling and exploration campaign. An updated NI 43-101 compliant, Measured and Indicated resource estimate on the main Canadian Malartic gold deposit was released on September 8, 2008 and has been filed on SEDAR. This updated resource estimate did not include the South Barnat Zone nor any other mineralized zone located outside the main deposit that is currently being evaluated by Osisko.

Mr. Robert Wares, P. Geo. and Executive Vice-President of Osisko, is the Qualified Person responsible for the technical information reported in this news release.

Forward Looking Statements

Certain statements contained in this press release may be deemed "forward-looking statements". All statements in this release, other than statements of historical fact, that address events or developments that the Corporation expects to occur, are forward looking statements. Forward looking statements are statements that are not historical facts and are generally, but not always, identified by the words "expects", "plans", "anticipates", "believes", "intends", "estimates", "projects", "potential", "scheduled" and similar expressions, or that events or conditions "will", "would", "may", "could" or "should" occur. Although the Corporation believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, including, without limitation that all technical, economical and financial conditions will be met in order to put the Canadian Malartic Project into commercial production, such statements are not guarantees of future performance and actual results may differ materially from those in forward looking statements. Factors that could cause the actual results to differ materially from those in forward-looking statements include gold prices, access to skilled consultants, mining development and mill production personnel, results of exploration and development activities, the Corporation's limited experience with production and development stage mining operations, uninsured risks, regulatory changes, defects in title, availability of personnel, materials and equipment, timeliness of government approvals, actual performance of facilities, equipment and processes relative to specifications and expectations, unanticipated environmental impacts on operations market prices, continued availability of capital and financing and general economic, market or business conditions. These factors are discussed in greater detail in the Corporation's most recent Annual Information Form filed on SEDAR, which also provides additional general assumptions in connection with these statements. The Corporation cautions that the foregoing list of important factors is not exhaustive. Investors and others who base themselves on the Corporation's forward-looking statements should carefully consider the above factors as well as the uncertainties they represent and the risk they entail. The Corporation believes that the expectations reflected in those forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward-looking statements included in this press release should not be unduly relied upon. These statements speak only as of the date of this press release.

Contacts: Osisko Mining Corporation John Burzynski Vice-President Corporate Development 514-735-7131 www.osisko.com Daniel Boase Investor Relations 416-742-5600 Toll Free: 1-866-580-8891

SOURCE: Osisko Mining Corporation

http://www.osisko.com