Mr. John Burzynski reports

OSISKO INTERSECTS 9.76 G/T AU OVER 7.3 METRES AT WINDFALL

Osisko Mining Inc. has released new results from the continuing drill program at its 100-per-cent-owned Windfall Lake gold project located in Urban township, Quebec. The current 400,000-metre drill program combines definition drilling above the Red Dog intrusion, expansion drilling above and below Red Dog, expansion drilling to the northeast of the main deposit, and exploration drilling on the greater deposit and Urban-Barry project area. Twelve drills are currently active on the Windfall deposit, at the Black Dog discovery and on the greater project area. Five additional drills will be added by the end of this month. New analytical results from three drill holes focused on expansion and infill drilling in the Caribou and Underdog corridors are reported in this release, with significant assay results presented in the associated table.

Significant new results include: 9.76 grams per tonne gold over 7.3 metres in OSK-W-16-754; 7.61 g/t Au over seven metres and 8.95 g/t Au over 2.1 metres in OSK-W-16-762; and 9.10 g/t Au over 2.6 metres in OSK-W-16-743-W2.

                             DRILL RESULTS

Hole                   From         To      Interval               Au
No.                     (m)        (m)           (m)            (g/t)

OSK-W-16-743-W2     1,373.7    1,376.3           2.6             9.10
including           1,374.5    1,375.3           0.8             27.5
OSK-W-16-754        1,422.7    1,430.0           7.3             9.76
including           1,424.0    1,425.6           1.6             34.6
OSK-W-16-762          622.0      624.0           2.0             8.89
including             623.0      624.0           1.0             17.7
OSK-W-16-762          666.0      673.0           7.0             7.61
OSK-W-16-762          682.0      684.1           2.1             8.95
OSK-W-16-762          693.0      696.0           3.0             4.47
including             694.0      695.0           1.0             7.24
           
Notes
True widths are estimated at 65 to 80 per cent of the reported core 
length interval. See quality control.
  
 

Underdog corridor

Drill holes OSK-W-16-754 and OSK-W-743-W2 expanded the mineralization in the Underdog corridor. This sector is identified as a high priority for drilling due to its potential to quickly generate new mineral resources. The FW3 zone, to date, identified over an area of 640 metres laterally and 730 metres vertically, remains open up and down plunge.

OSK-W-16-754 intersected 9.76 g/t Au over 7.3 metres in a moderately sericitized and silicified porphyry dike containing 4 to 8 per cent pyrite stringers. This intersection is located 160 metres down plunge from previously drilled OBM-15-564 (which returned 5.32 g/t Au over 2.1 metres) and confirms the extension of the high-grade FW3 gold mineralization to a vertical depth of 1,190 metres. This hole also indicates that the FW3 zone remains open at depth and down plunge.

OSK-W-16-743-W2 intersected 9.10 g/t Au over 2.6 metres, extending the FW2 zone by 265 metres down plunge from previously drilled OSK-W-16-743-W1 (which returned 8.13 g/t Au over 2.6 metres), and 210 metres below the previously drilled DDH OSK-W-16-743 (which returned 47.0 g/t Au over 2.6 metres; 303.1 g/t Au over 2.6 metres uncut). Mineralization consists of traces to 10 per cent pyrite stringers and disseminations in a strongly silicified and sericitized fragmental porphyry dike. The FW0 zone returned 3.52 g/t Au over 2.9 metres in a strongly sericitized andesite containing 3 to 10 per cent pyrite stringers and disseminations.

Caribou corridor

OSK-W-16-762 intersected several parallel zones of the Caribou corridor. The Caribou South 3 (CS3) zone was expanded by 87 metres in its southwest extension with 7.61 g/t Au over seven metres at the contact between a strongly sericitized and silicified andesite and porphyry dikes. The CS3-FW zone intersected 8.95 g/t Au over 2.1 metres in a weakly sericitized andesite containing 2 to 3 per cent pyrite stringers and disseminations. The CS1 zone returned 8.89 g/t Au over two metres in a weakly sericitized andesite containing 1 to 3 per cent pyrite stringers.

Qualified person

The scientific and technical content of this news release has been reviewed, prepared and approved by Dr. Jean-Philippe Desrochers, PhD, PGeo, senior project manager of the Windfall Lake gold project, who is a qualified person as defined by National Instrument 43-101 -- standards of disclosure for mineral projects.

Quality control and reporting protocols

True widths of the new exploration intercepts below Red Dog reported in this press release have yet to be determined. Additional drilling is planned for the immediate area which will enable the true width determination. True widths of intercepts in the zones above the Red Dog are estimated at 65 to 80 per cent of the reported core length intervals. Assays are uncut except where indicated, and calculated intervals are reported over a minimum length of two metres using a lower cut-off of three g/t Au. All NQ core assays reported were obtained by either one-kilogram whole rock metallic screen/fire assay or standard 50-gram fire assaying with AA (atomic absorption) or gravimetric finish at ALS Laboratories in Val d'Or, Que., or Sudbury, Ont. The one-kilogram metallic screen assay method is selected by the geologist when samples contain coarse gold or present a higher percentage of pyrite than surrounding intervals. All samples are also analyzed for multielements, including silver, using an aqua regia ICP-AES (inductively coupled plasma atomic emission spectroscopy) method at ALS Laboratories. Drill program design, quality assurance/quality control and interpretation of results are performed by qualified persons employing a quality assurance/quality control program consistent with National Instrument 43-101 and industry best practices. Standards and blanks are included with every 20 samples for quality assurance/quality control purposes by the corporation as well as the lab. Approximately 5 per cent of sample pulps are sent to secondary laboratories for check assays.

About the Windfall Lake gold deposit

The Windfall Lake gold deposit is located between Val d'Or and Chibougamau in the Abitibi region of Quebec, Canada. The current mineral resource comprises 2,762,000 tonnes at 8.42 g/t Au (748,000 ounces) in the indicated category and 3,512,000 tonnes at 7.62 g/t Au (860,000 ounces) in the inferred category (sourced from a technical report dated June 10, 2015, entitled "Preliminary economic assessment of the Windfall Lake gold property, Quebec, Canada," with an effective date of April 28, 2015, prepared in accordance with NI 43-101). The Windfall Lake gold deposit is currently one of the highest-grade resource-stage gold projects in Canada. The bulk of the mineralization occurs in the main zone, a southwest/northeast-trending zone of stacked mineralized lenses, measuring approximately 600 metres wide and at least 1,400 metres long. The deposit is well defined from surface to a depth of 500 metres, and remains open along strike and at depth. Mineralization has been identified only 30 metres from surface in some areas and as deep as 870 metres in others, with significant potential to extend mineralization up and down plunge and at depth.

About Osisko Mining Inc.

Osisko is a mineral exploration company focused on the acquisition, exploration and development of precious metal resource properties in Canada. Osisko holds a 100-per-cent interest in the high-grade Windfall Lake gold deposit located between Val d'Or and Chibougamau in Quebec and holds a 100-per-cent undivided interest in a large area of claims in the surrounding Urban Barry area (82,400 hectares), a 100-per-cent interest in the Marban project located in the heart of Quebec's prolific Abitibi gold mining district, and properties in the Larder Lake mining division in Northeast Ontario, including the Jonpol and Garrcon deposits on the Garrison property, the Buffonta past-producing mine and the Gold Pike mine property. The corporation also holds interests and options in a number of additional properties in Northern Ontario.

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