Category: Silver / Gold

Osisko Intersects 3.19 g/t Au Over 76.5 Metres at South Barnat

Osisko Mining Corporation ("Osisko")(TSX: OSK.TO)(FRANKFURT: EWX.F) is pleased to provide new results as well as an update from the definition drill program currently under way on the South Barnat Zone, a separate gold mineralized system located approximately 1200 metres northeast of the center of the Canadian Malartic deposit.

New drill results from the current program include 3.19 g/t Au over 76.5 metres (BA08-3124), 1.62 g/t Au over 177.0 metres (BA08-3142) and 2.03 g/t Au over 131.8 metres (BA08-3143). Narrow higher-grade intervals include 15.4 g/t Au over 6.0 metres (BA08-3135).

The definition drill program is focused on an 850 metre-long grid oriented northwest-southeast with drill sections spaced 50 metres apart (Phase 14 of the Canadian Malartic drill program). All holes on this grid are inclined 45 to 75 degrees to the northeast or southwest.

Phase 14 has now been completed with 228 drill holes totaling 50,200 metres, of which assay results have been processed and released for 145 holes, including new results in this press release. The weighted average grade of a total of 10,700 metres of mineralized intersections intersected to date is 1.91 g/t Au (calculated using an upper cut of 30 g/t Au and a minimum of 0.50 g/t Au over successive maximum intervals of 20 metres).

Phase 15 is underway with infill drilling on remaining sections spaced 25 metres apart. Approximately 45,000 metres of this phase have been drilled to date, from a total drill program estimated at 120,000 metres and expected to be completed by the end of January 2009.

Wireframe modeling of the deposit and of underground voids will begin next week with the objective of releasing an inferred resource estimate by the end of January 2009. With the completion and integration of the Phase 15 drilling, the Company plans on completing a measured and indicated resource estimate by Q2 2009.

Results from twenty-two new holes are tabled below:

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Hole No.            Section     From (m)     To (m)   Length (m)     Au g/t
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BA08-3121              350E        43.2       78.3       35.1          1.85
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BA08-3122              350E        23.0       47.3       24.3          1.54
 And                               68.0       89.0       21.0          4.09
 including                         69.5       71.3        1.8         23.70
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BA08-3123              350E       266.1      296.6       30.5          1.00
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BA08-3124              350E       155.5      232.0       76.5          3.19
 including                        176.0      177.5        1.5         23.00
 And                              264.5      316.0       51.5          1.70
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BA08-3125              300E         0.8       95.5       94.7          0.92
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BA08-3126              600E        36.0      236.5      200.5          1.26
 including                         42.5       44.0        1.5         30.10
 And                              272.5      423.0      150.5          0.85
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BA08-3127              350E         6.0       92.7       86.7          0.93
 And                              122.5      157.0       34.5          1.83
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BA08-3128              250E        15.6       74.5       58.9          1.93
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BA08-3129              250E        15.0       48.0       33.0          2.72
 including                         25.5       27.0        1.5         38.90
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BA08-3130              250E        15.3      114.5       99.2          1.49
 including                         75.0       76.0        1.0         27.30
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BA08-3133              400E        22.7       71.5       48.8          5.78
 including                         53.5       55.0        1.5         97.70
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BA08-3134              525E        21.0       81.0       60.0          1.78
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BA08-3135              525E        24.5       72.3       47.8          3.50
 including                         45.0       51.0        6.0          15.4
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BA08-3136              525E        38.5       70.4       31.9          2.84
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BA08-3138              450E        79.0       99.0       20.0          1.31
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BA08-3139              450E        45.9       73.0       27.1          1.70
 And                              194.5      286.0       91.5          1.08
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BA08-3140              700E       194.5      223.0       28.5          1.70
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BA08-3141              700E       205.0      268.0       63.0          4.64
 including                        253.0      254.5        1.5         99.10
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BA08-3142              700E       175.0      352.0      177.0          1.62
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BA08-3143              500E        60.0      191.8      131.8          2.03
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BA08-3144              500E        12.7       96.0       83.3          0.89
 And                              128.5      218.1       89.6          1.90
 including                        132.5      134.0        1.5         25.50
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BA08-3145              500E        70.0       97.8       27.8          1.70
 And                              163.8      211.9       48.1          1.18
 And                              266.5      282.5       16.0          1.47
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