Osisko Intersects 71.9 g/t Au Over 2.9 Metres At Lynx

(Toronto, February 27, 2018)  Osisko Mining Inc. (OSK:TSX. “Osisko” or the “Corporation”) is pleased to provide new results from the ongoing drill program at its 100% owned Windfall Lake gold project located in the Abitibi greenstone belt, Urban ownship, Eeyou Istchee James Bay, Québec. The 800,000 metre drill program combines definition, expansion and exploration drilling in and around the main Windfall gold deposit and the adjacent Lynx deposit (located immediately NE of Windfall).

Significant new analytical results from 31 intercepts in 22 drill holes and 3 wedges focused on infill and expansion drilling in the Lynx deposit are presented below. Osisko continues to extend the known Lynx zones of mineralization through the application of the Windfall geological model and as the density of drilling increases.

Highlights from the new results include: 71.9 g/t Au over 2.9 metres OSK-W-17-941; 76.4 g/t Au over 2.4 metres and 52.5 g/t Au over 2.1 metres in OSK-W-17-1367-W1, 52.3 g/t Au over 2.1 metres in OSK-W-17-967, 40.6 g/t Au over 2.3 metres in OSK-W-17-1413; 48.0 g/t Au over 2.0 metres in OSK-W-18-1422 and 10.1 g/t Au over 6.5 metres in OSK-W-18-1415. Maps showing hole locations and full analytical results are available at www.osiskomining.com.

Hole Number From
(m)
To
(m)
Interval
(m)
Au (g/t)
uncut
Au (g/t)
cut to
100 g/t
Zone Corridor
OSK-W-17-898 375.5 380.7 5.2 3.75   Lynx 3 Lynx
including 375.5 376.2 0.7 10.8  
including 380.2 380.7 0.5 16.4  
OSK-W-17-907 893.0 895.0 2.0 5.71   Lynx 4 Lynx
including 894.0 895.0 1.0 10.3      
OSK-W-17-941 231.0 233.9 2.9 71.9 25.9 Lynx 2 Lynx
including 231.85 232.15 0.3 545 100
OSK-W-17-967 240.9 243.0 2.1 52.3 47.7 VNCR Lynx
including 242.0 243.0 1.0 109 100
OSK-W-17-1099 108.0 110.1 2.1 3.04   Lynx 2 Lynx
including 109.8 110.1 0.3 14.5  
OSK-W-17-1104 560.0 562.0 2.0 4.30   Lynx HW Lynx
including 560.5 561.3 0.8 10.4  
  591.8 594.0 2.2 4.06   Lynx HW Lynx
including 591.8 592.3 0.5 17.8  
OSK-W-17-1113 363.4 366.0 2.6 3.33   Vein Lynx
including 365.6 366.0 0.4 19.5  
OSK-W-17-1115 693.0 695.0 2.0 11.7   Vein Lynx
OSK-W-17-1147 712.8 716.5 3.7 3.29   Lynx 4 Lynx
including 712.8 713.1 0.3 24.4  
OSK-W-17-1177 575.0 577.0 2.0 3.21   Lynx 1 Lynx
OSK-W-17-1181-W3 1113.7 1116.4 2.7 6.11   Lynx 4 Lynx
OSK-W-17-1187 264.0 266.7 2.7 3.43   Lynx 3 Lynx
OSK-W-17-1190 430.0 432.0 2.0 5.91   Lynx 1 Lynx
including 430.6 431.6 1.0 11.6  
OSK-W-17-1193 979.0 981.8 2.8 4.48   Lynx 4 Lynx
OSK-W-17-1290 423.0 427.0 4.0 34.5   Vein Lynx
including 425.0 427.0 2.0 67.5      
OSK-W-17-1293 41.5 44.0 2.5 14.4   Lynx 1 Lynx
including 43.0 44.0 1.0 35.4  
OSK-W-17-1356 229.6 232.0 2.4 4.14   Lynx 1 Lynx
OSK-W-17-1367-W1 1009.5 1011.6 2.1 52.5 29,2 Lynx 4 Lynx
including 1010.3 1010.9 0.6 182 100
  1016.6 1019.0 2.4 76.4 28.3 Lynx 4 Lynx
including 1016.6 1017.1 0.5 331 100
OSK-W-17-1396 897.0 899.8 2.8 6.13   Lynx 4 Lynx
OSK-W-17-1413 296.0 298.3 2.3 40.6 39.4 Lynx 2 Lynx
including 297.4 298.3 0.9 103 100
  967.8 970.2 2.4 8.35   Lynx 6 Lynx
including 967.8 968.7 0.9 15.9  
OSK-W-18-1414-W1 842.4 846.0 3.6 8.20   Lynx 1 Lynx
including 842.4 843.0 0.6 20.6  
including 844.8 845.3 0.5 17.1  
  855.2 857.9 2.7 26.5   Lynx 1 Lynx
OSK-W-18-1415 457.0 463.5 6.5 10.1   Lynx HW Lynx
including 457.0 457.7 0.7 68.8  
OSK-W-18-1418 544.0 546.3 2.3 8.09   Lynx 4 Lynx
including 545.2 545.5 0.3 61.0  
  551.0 553.2 2.2 4.02   Lynx 4 Lynx
OSK-W-18-1422 386.0 388.0 2.0 48.0 21.8 Lynx HW Lynx
including 386.7 387.1 0.4 231 100
OSK-W-18-1423 107.5 109.6 2.1 7.77   Lynx 1 Lynx
including 108.5 108.9 0.4 38.7  
  221.2 223.7 2.5 4.65   VNCR Lynx

Notes:

  1. True widths are estimated at 65 – 80% of the reported core length interval.  See “Quality Control” below.
  2. Definitions: HW = Hanging Wall, VNCR = Crustiform Vein
Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Section
OSK-W-17-898 148 -51 555 453330 5435403 3675
OSK-W-17-907 134 -51 1317 453219 5435340 3575
OSK-W-17-941 330 -49 444 453434 5434969 3575
OSK-W-17-967 337 -62 720 453176 5434908 3300
OSK-W-17-1099 335 -56 264 453143 5434935 3300
OSK-W-17-1104 142 -50 1059 453383 5435455 3775
OSK-W-17-1113 138 -50 480 453280 5435347 3625
OSK-W-17-1115 153 -48 816 452796 5435118 3075
OSK-W-17-1147 335 -52 817 453241 5434380 3125
OSK-W-17-1177 340 -67 1422 454113 5435090 4225
OSK-W-17-1181-W3 133 -58 1247 453789 5435793 4275
OSK-W-17-1187 333 -55 477 453441 5435025 3600
OSK-W-17-1190 151 -49 1179 452905 5435152 3200
OSK-W-17-1193 141 -59 1803 453806 5435726 4275
OSK-W-17-1290 130 -52 462 453131 5435356 3500
OSK-W-17-1293 329 -70 828 452904 5434849 3050
OSK-W-17-1356 334 -67 429 453442 5435026 3600
OSK-W-17-1367-W1 131 -52 1161 453753 5435875 4300
OSK-W-17-1396 134 -52 956 453439 5435484 3825
OSK-W-17-1413 137 -53 996 453153 5435214 3450
OSK-W-18-1414-W1 133 -57 1198 453654 5435648 4100
OSK-W-18-1415 139 -49 561 453491 5435453 3850
OSK-W-18-1418 334 -45 1077 453288 5434531 3225
OSK-W-18-1422 140 -45 476 453492 5435452 3850
OSK-W-18-1423 327 -61 792 453025 5434853 3150
 

OSK-W-17-898 intersected Lynx 3 with 3.75 g/t Au over 5.2 metres. Mineralization is composed of 4% disseminated pyrite and 3% pyrite stringers hosted in quartz-tourmaline and quartz-carbonates veins in a fragmental felsic dike.

OSK-W-17-907 intersected Lynx 4 with 5.71 g/t Au over 2.0 metres. Mineralization is composed of 1% quartz-tourmaline veins with pyrite and 1% pyrite-silica flooding within a strongly sericitized and silicified rhyolite.

OSK-W-17-941 intersected 71.9 g/t Au over 2.9 metres in Lynx 2. Mineralization is composed of local visible gold within a silicified and weakly sericitized fragmental felsic dike.

OSK-W-17-967 intersected crustiform veins returning 52.3 g/t Au over 2.1 metres in the Lynx 2 Mineralization is composed of 1% disseminated pyrite in quartz-carbonate-chlorite veins within a sericitized gabbro.

OSK-W-17-1099 intersected 3.04 g/t Au over 2.1 metres in Lynx 2. Mineralization is composed of up to 2% pyrite clusters, 10% pyrite in pervasive silica flooding and 3% pyrite-tourmaline stringers hosted in a silica altered fragmental felsic dike.

OSK-W-17-1104 intersected 4.30 g/t Au over 2.0 metres and 4.06 g/t Au over 2.2 metres in Lynx HW. Mineralization is composed of up to 3% disseminated and stringer pyrite within a gabbro with sericite and fuchsite alteration.

OSK-W-17-1113 intersected 3.33 g/t Au over 2.6 metres. Mineralization is composed of quartz veins with trace pyrite stringers and 1% pyrite clusters and quartz-carbonate veins in a weakly sericitized rhyolite.

OSK-W-17-1115 intersected 11.7 g/t Au over 2.0 metres related to vein type mineralization. The interval is composed of 5% pyrite-tourmaline stringers and quartz veins within a chloritized andesite.

OSK-W-17-1147 intersected 3.29 g/t Au over 3.7 metres in Lynx 4. Mineralization is composed of 1% pyrite clusters with ptygmatic tourmaline veins within a sericitized rhyolite.

OSK-W-17-1177 intersected Lynx 1 with 3.21 g/t Au over 2.0 metres. Mineralization is composed of 1% pyrite stringers and tourmaline veins at a fuchsite altered contact between a gabbro and a porphyritic felsic dike.

OSK-W-17-1181-W3 intersected Lynx 4 with 6.11 g/t Au over 2.7 metres. Mineralization is composed of disseminated pyrite and tourmaline ptygmatic veins in a porphyritic felsic dike crosscutting a gabbro.

OSK-W-17-1187 intersected Lynx 3 with 3.43 g/t Au over 2.7 metres. Mineralization is composed of 4% pyrite clusters and 2% pyrite stringers with pervasive silica alteration in a sericitized porphyritic felsic dike.

OSK-W-17-1190 intersected 5.91 g/t Au over 2.0 metres in Lynx 1. Mineralization is composed of 5% pyrite stringers and 3% pyrite-silica flooding within a moderate sericite altered porphyritic felsic dike.

OSK-W-17-1193 intersected Lynx 4 with 4.48 g/t Au over 2.8 metres. Mineralization is composed of up to 2% pyrite stringers within a strongly sericitized felsic porphyritic dike.

OSK-W-17-1290 intersected 34.5 g/t Au over 4.0 metres in a vein within the Lynx Corridor. Mineralization is composed of traces of disseminated pyrite within a gabbro with strong chlorite and carbonate alteration.

OSK-W-17-1293 intersected Lynx 1 with 14.4 g/t Au over 2.5 metres. Mineralization is composed of disseminated pyrite, pyrite stringers and quartz-carbonates veins in a chloritized mafic intrusion bordered by the Bank fault deformation zone.

OSK-W-17-1356 intersected Lynx 1 with 4.14 g/t Au over 2.4 metres. Mineralization is composed of traces of pyrite clusters and/or fragments and pyrite stringers at the contact between a sericitized fragmental intrusive unit and an andesite.

OSK-W-17-1367-W1 intersected Lynx 4 with 52.5 g/t Au over 2.1 metres and 76.4 g/t Au over 2.4 metres. The first interval is composed of 4% pyrite clusters in 10 centimetres quartz-tourmaline veins and disseminated pyrite in a strongly fuchsite altered gabbro. The second interval is composed of trace pyrite-tourmaline stringer, 1% disseminated pyrite and 4% pyrite in ptygmatic tourmaline veinlets with trace chalcopyrite. Local visible gold is present in brittle fractures crosscutting tourmaline ptygmatic veins at contact between a small porphyritic dike and a fuchsite altered gabbro.

OSK-W-17-1396 intersected 6.13 g/t Au over 2.8 metres in Lynx 4. The mineralization is composed of up to 15% pyrite in quartz-tourmaline veins and 1% chalcopyrite within a sericitized and bleached mafic intrusion.

OSK-W-17-1413 intersected Lynx 2 with 40.6 g/t Au over 2.3 metres and Lynx 6 with 8.35 g/t Au over 2.4 metres. The first interval is composed of local visible gold and 1% pyrite clusters within a rhyolite with intense pervasive silica flooding. The second interval is composed of local visible gold and 3% disseminated pyrite in carbonate fracture filling, 2% pyrite stringers in smoky quartz veins hosted in a sheared andesite with chlorite alteration.

OSK-W-18-1414-W1 intersected Lynx 1 with 8.20 g/t Au over 3.6 metres and 26.5 g/t Au over 2.7 metres. The first interval is composed of up to 7% pyrite clusters, up to 3% pyrite stringers and ptygmatic quartz-tourmaline veins within a sericitized gabbro and rhyolite contact. The second interval is composed of up to 5% pyrite-silica flooding and 3% pyrite stringers within a strong silica altered rhyolite.

OSK-W-18-1415 intersected Lynx HW with 10.1 g/t Au over 6.5 metres. Mineralization is composed of local visible gold, up to 15% pyrite with pervasive silica flooding within a weakly bleached, sericitized and fuchsite altered gabbro.

OSK-W-18-1418 intersected Lynx 4 with 8.09 g/t Au over 2.3 metres and 4.02 g/t Au over 2.2 metres. Mineralization is composed of up to 5% pyrite stringers and 3% pyrite clusters in smoky quartz with, local carbonate in fracture filling and disseminated tourmaline hosted in a sericitized and silicified rhyolite.

OSK-W-18-1422 intersected Lynx hanging wall with 48.0 g/t Au over 2.0 metres. Mineralization is composed of up to 5% pyrite stringers, up to 3% pyrite clusters and 2% disseminated pyrite within a sericite, fuchsite and silica altered gabbro.

OSK-W-18-1423 intersected two interval 7.77 g/t Au over 2.1 metres in Lynx 1 and 4.65 g/t Au over 2.5 metres in a crustiform vein. The first interval is composed of 3% pyrite stringers, 1% pyrite clusters and crustiform quartz-carbonates veins within a strongly sericitized felsic porphyritic dike. The second interval is composed of up to 4% pyrite-tourmaline stringer and quartz-carbonate vein within a sericite, fuchsite, chlorite and carbonate altered andesite.

Qualified Person

The scientific and technical content of this news release has been reviewed, prepared and approved by Mr. Louis Grenier, M.Sc.A., P.Geo. (OGQ 800), 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 (“NI 43-101”).

Quality Control and Reporting Protocols

True widths determinations are estimated at 65-80% of the reported core length intervals for most of the zones. Assays are uncut except where indicated. Intercepts occur within geological confines of major zones but have not been correlated to individual vein domains at this time. Reported intervals include minimum weighted averages of 3.0 g/t Au diluted over core lengths of at least 2.0 metres. All NQ core assays reported were obtained by either 1-kilogram screen fire assay or standard 50-gram fire-assaying-AA finish or gravimetric finish at ALS Laboratories in Val d’Or, Québec, Thunder Bay and Sudbury, Ontario or Vancouver, British Colombia or Bureau Veritas in Timmins, Ontario. The 1-kilogram screen assay method is selected by the geologist when samples contain coarse gold or present a higher percentage of pyrite than surrounding intervals. Selected samples are also analyzed for multi-elements, including silver, using an Aqua Regia-ICP-AES method at ALS Laboratories. Drill program design, Quality Assurance/Quality Control (“QA/QC”) and interpretation of results is performed by qualified persons employing a QA/QC program consistent with NI 43-101 and industry best practices. Standards and blanks are included with every 20 samples for QA/QC purposes by the Corporation as well as the lab. Approximately 5% of sample pulps are sent to secondary laboratories for check assay.

About the Windfall Lake Gold Deposit

The Windfall Lake gold deposit is located between Val-d’Or and Chibougamau in the Abitibi region of Québec, Canada. The mineral resource defined by the previous operator 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, Québec, 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% in the high-grade Windfall Lake gold deposit located between Val-d’Or and Chibougamau in Québec and holds a 100% undivided interest in a large area of claims in the surrounding Urban Barry area and nearby Quevillon area (over 3,300 square kilometres), a 100% interest in the Marban project located in the heart of Québec’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 Quebec and Ontario.  Osisko continues to be well financed with approximately $190 million in cash and investments (based on figures available as of December 31, 2017).

Cautionary Note Regarding Forward-Looking Information

This news release contains “forward-looking information” within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections and interpretations as at the date of this news release. The information in this news release about the Windfall Lake gold deposit being one of the highest grade resource-stage gold projects in Canada; the current 800,000 metre drill program; the significance of new results from the ongoing drill program at the Windfall Lake gold project; the significance of assay results presented in this press release describing the analytical results from 31 intercepts in 22 holes and 3 wedges focused on infill and expansion drilling in the Lynx deposit; the high-grade core developing at Lynx 4; the type of drilling included in the drill program (definition, expansion and exploration drilling in and around the main Windfall Lake gold deposit and the adjacent Lynx deposit, and exploration drilling on the greater deposit and Urban-Barry project area); potential mineralization; the potential to extend mineralization up and down-plunge and at depth at the Windfall Lake gold deposit; the ability to realize upon any mineralization in a manner that is economic; the ability to complete any proposed exploration activities and the results of such activities, including the continuity or extension of any mineralization; and any other information herein that is not a historical fact may be “forward-looking information”. Any statement that involves discussions with respect to predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often but not always using phrases such as “expects”, or “does not expect”, “is expected”, “interpreted”, “management’s view”, “anticipates” or “does not anticipate”, “plans”, “budget”, “scheduled”, “forecasts”, “estimates”, “believes” or “intends” or variations of such words and phrases or stating that certain actions, events or results “may” or “could”, “would”, “might” or “will” be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This forward-looking information is based on reasonable assumptions and estimates of management of the Corporation. at the time it was made, involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Osisko to be materially different from any future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, risks relating to the ability of exploration activities (including drill results) to accurately predict mineralization; errors in management’s geological modelling; the ability of Osisko to complete further exploration activities, including drilling; property interests in the Windfall Lake gold project; the ability of the Corporation to obtain required approvals and complete transactions on terms announced; the results of exploration activities; risks relating to mining activities; the global economic climate; metal prices; dilution; environmental risks; and community and non-governmental actions. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions. Osisko cannot assure shareholders and prospective purchasers of securities of the Corporation that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither Osisko nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information, Osisko does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

For further information please contact:
John Burzynski. President and Chief Executive Officer
Telephone: (416) 363-8653

Osisko Intersects 2.51 g/t Au Over 73.0 Metres At Garrison

(Toronto, February 15, 2018).  Osisko Mining Inc. (OSK:TSX) (“Osisko” or the “Corporation”) is pleased to announce the final results from the 2017 drill program at its 100% owned Garrison gold project located in Garrison Township, Ontario.  Over 85,000 metres of new drilling have been conducted by Osisko on the Garrison Project since its acquisition in late 2015.  A total of fifteen new intercepts in seven holes are reported in this release, with significant assay results presented in the table below.

Significant new results include:  2.51 g/t Au over 73.0 metres in OSK-G17-453; 1.98 g/t Au over 14.5 metres and 1.76 g/t Au over 25.5 metres in OSK-G17-461; 2.18 g/t Au over 9.0 metres in OSK-G17-445; and 1.27 g/t Au over 22.3 metres in OSK-G17-467.

The new results continue to show the increasing potential of the 903 Zone with proven extension towards SW, NW and South and to confirm the extent of known mineralization in the Garrcon Zone. Maps and sections showing hole locations and complete drilling results are available at www.osiskomining.com

Hole No. From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t)
cut to
30 g/t
Zone
OSK-G17-445 233.0 242.0 9.0 2.18   Garrcon
including 241.0 242.0 1.0 16.0   Garrcon
  355.0 357.0 2.0 4.58   Garrcon
OSK-G17-453 371.0 444.0 73.0 2.51   903
including 375.0 376.0 1.0 8.54   903
and 378.3 379.6 1.3 8.62   903
and 384.5 387.0 2.5 4.59   903
and 428.8 429.8 1.0 10.3   903
and 438.8 442.8 4.0 6.10   903
OSK-G17-456 150.0 153.2 3.2 1.95   903
OSK-G17-461 42.0 56.5 14.5 1.98   903
including 42.0 47.0 5.0 4.25   903
  81.0 106.5 25.5 1.76   903
including 81.0 86.5 5.5 3.81   903
OSK-G17-463 196.0 256.5 60.5 0.71   903
including 212.0 230.5 18.5 1.39   903
OSK-G17-466 176.0 179.0 3.0 1.10   903
  244.7 245.1 0.4 14.1   903
OSK-G17-467 326.2 348.5 22.3 1.27   903
including 330.0 335.0 5.0 4.08   903
OSK-G17-468 313.4 332.6 19.2 0.75   903
including 322.0 328.0 6.0 1.35   903

Notes:  True Widths are estimated at 65 – 90% of the reported core length interval.  See “Quality Control” below.

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Section
OSK-G17-445 340 -45 582.0 578739 5373697 1200W
OSK-G17-453 340 -45 483.0 577579 5373080 2500W
OSK-G17-456 340 -45 306.0 577329 5373183 2700W
OSK-G17-461 340 -45 228.0 577180 5373229 2825W
OSK-G17-463 340 -50 272.0 577442 5373164 2600W
OSK-G17-466 340 -45 324.0 577034 5373406 2900W
OSK-G17-467 340 -50 462.0 576885 5372790 3250W
OSK-G17-468 340 -50 477.0 576980 5372828 3150W
 

OSK-G17-445 intercepted two main mineralized intervals: 2.18 g/t Au over 9.0 metres; and 4.58 g/t Au over 2.0 metres. The intervals are associated with centimetre-scale quartz-carbonate stringers with trace sulfide as well as albite, sericite and carbonate alteration hosted by Temiskaming sediments.

OSK-G17-453 was drilled 25 metres underneath OSK-G17-390 (see press release Jan 15, 2018) as an infill hole intercepting 2.51 g/t Au over 73.0 metres. Mineralization is hosted by a thick syenite dyke with intense albite-hematite alteration and zones of strong fracturing, veining and coarse euhedral pyrite.

OSK-G17-456 was drilled in the south-central part of the 903 Zone, 250 metres northwest from OSK-G17-453 (described above). The hole intercepted a mineralized zone hosted in syenite dykes averaging 1.95 g/t Au over 3.2 metres. The syenite dykes are intruding fuchsite altered ultramafic rocks.

OSK-G17-461 intercepted two mineralized zones close to surface averaging 1.98 g/t Au over 14.5 metres and 1.76 g/t Au over 25.5 metres, both in syenite dykes with intense veining, albite alteration, specularite and pyrite.

OSK-G17-463 was drilled at the south part of the 903 Zone, intercepting a wide zone averaging 0.71 g/t Au over 60.5 metres that included 1.39 g/t Au over 18.5 metres. Mineralization is hosted by a crowded porphyritic syenite with moderate albite alteration and quartz veining.

OSK-G17-466 was drilled at the northern part of the 903 Zone and intersected 1.1 g/t Au over 3.0 metres in  a syenite dyke.  A small zone of hematite alteration in mafic volcanic rocks returned 14.1 g/t Au over 0.4 metres.

OSK-G17-467 was drilled 50m west of OSK-G17-439 (see press release Jan 15th 2018), to intercept the mineralization observed in the footwall of a diabase dyke. The hole successfully intercepted 1.27 g/t Au over 22.3 metres including 4.08 g/t Au over 5.0 metres in strongly sheared ultramafic rocks with quartz-sericite-pyrite alteration in the hanging wall of the mentioned diabase dyke.

OSK-G17-468 intercepted 0.75 g/t Au over 19.2 metres including 1.35 g/t Au over 6.0 metres in a deformed layer of sediments with albite-sericite alteration and disseminated pyrite.

Qualified Person
The scientific and technical content of this press release has been reviewed, prepared and approved by Mr. Gernot Wober, P.Geo. VP Exploration Canada for Osisko Mining Inc, who is a “Qualified Person” as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”).

Quality Control
True widths of the new exploration intercepts reported in this press release have yet to be determined, but are  typically 65 – 90% of reported core lengths. Additional drilling is planned for the immediate area which will enable the true width determination. Assays are uncut except where indicated, and calculated intervals are reported over a minimum length of 2 metres using a lower cutoff of 1.0 g/t Au. All HQ core assays reported were obtained by either whole sample rock metallic screen/fire assay or standard 30 gram fire-assaying with ICP finish at SGS Minerals Services in Cochrane, Ontario; and Bureau Veritas in Timmins, Ontario. The whole sample metallic screen assay method is selected by the geologist when samples contain coarse gold or any samples displaying gold initial fire assay values greater than 3g/t. Drill program design, Quality Assurance/Quality Control and interpretation of results is performed by qualified persons employing a Quality Assurance/Quality Control program consistent with NI 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% of sample pulps are sent to secondary laboratories for check assays.

About the Garrison Project
The Garrison Project area is comprised of 214 mineral claims, 25 mining leases, and 87 patent claims encompassing approximately 8,000 hectares.  Both Garrcon and Jonpol have resource estimates that are described in a technical report prepared in accordance with NI 43-101, which was completed by a previous operator Northern Gold Mining Inc. (entitled “Technical Report on the Golden Bear Project – Garrison Property: Larder Lake Mining Division, Garrison Township, Ontario, Canada”) dated December 30, 2013, with an effective date of December 30, 2013 (the “Garrison Technical Report”). The Garrison Technical Report was prepared by A.C.A. Howe International Limited for Northern Gold Mining Inc. (a wholly-owned subsidiary of Osisko) and is available on Osisko’s website at www.osiskomining.com and on SEDAR under Northern Gold Mining Inc.’s issuer profile at www.sedar.com.

Resource estimates were conducted by A.C.A. Howe International Limited according to CIM standards. The Garrcon Zone estimates showed 15.1 million tonnes with an average grade of 1.07 g/t Au (521,000 oz) in measured resources; 14.1 million tonnes averaging 1.16 g/t Au (526,000 oz) in indicated resources; and 1.7 million tonnes averaging 0.72 g/t Au (39,000 oz) in inferred resources. Potential underground resources of 5.1 million tonnes averaging 3.49 g/t Au (577,000 oz) in the inferred category were also outlined. Resources were reported at a cut-off grade of 0.4 g/t Au for open pit extraction and 1.5 g/t in a bulk underground mining scenario using a gold price of US$1,250/oz.

At the Jonpol Zone, resources were estimated as 0.87 million tonnes averaging 5.34 g/t Au (150,000 oz) in the indicated category; and 1.07 million tonnes averaging 5.56 g/t Au (192,000 oz) in inferred resources. Resources were reported at a cut-off grade of 3.0 g/t Au and assume an underground extraction scenario using a gold price of US$1,250/oz.

Readers are cautioned that inferred resources have a great amount of uncertainty as to their existence and as to whether they can be mined economically. It cannot be assumed that all or any part of the inferred resources will ever be upgraded to a higher category. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

Garrcon Zone
The Garrcon Zone has a shallow plunge eastward along the footwall of the Destor-Porcupine Fault Zone with the bulk of the resource in the western, more densely drilled area. The zone is exposed at surface and has potential for open pit bulk mining at an estimated overall stripping ratio of 1.8:1. There is potential for additional underground resources below the pit and along the easterly plunge of the zone, which is open for further exploration down dip and along strike.

The Garrcon shaft was sunk in 1935 and 1936 by the Consolidated Mining and Smelting Co. of Canada (“Cominco”) and the Shaft and South Zones were tested for high grade gold mineralization. Cominco drove approximately 1,430 metres of drifts and cross cuts, mining underground veins. Diamond drilling by Cominco and Lac Minerals Ltd. in the mid-to-late 1980s identified broad sections of low grade mineralization. In 2006-2007, ValGold Resources Ltd. conducted additional drilling confirming these zones. From 2009-2013 Northern Gold Mining Inc. conducted 97,000 metres of diamond drilling which delineated the current resource.

In 2014, Northern Gold Mining Inc. was granted a trial mining permit allowing the extraction of up to 150,000 tonnes. Northern Gold Mining Inc. mined 73,534 dry tonnes which was processed at the nearby Holt mill facility recovering 3,516 oz at an average head grade of 1.55 g/t and recovery of 95.9%.

Jonpol Zone
Jonpol is situated in the Munro Fault Zone, a west striking splay off the north side of the Destor-Porcupine Fault. Hosted in a shear zone tens of metres wide in altered mafic volcanic rocks, the deposit consists of four high grade gold mineralized zones (JP, JD, RP and East) over a strike length of 1.7 kilometers. Gold mineralization is hosted in quartz carbonate veins, in mafic and ultramafic host rocks, and is associated with intense albite and/or sericite alteration and pyrite mineralization.

In 1997, a 49,087 tonne bulk sample was extracted from the central part of the JP zone by Hillsborough Resources Limited with an average grade of 6.7 g/t which produced 9,476 ounces Au. From 1985-2013, over 130,000 metres of drilling was completed on the property by previous operators. Development work on the JP zone included the sinking of a 184 metre shaft as well as development of a ramp to the 150 metres level with mining on six sublevels. The Jonpol infrastructure underwent reclamation in the late 1990s and was closed out in 2001, but the existing ramp and shaft are preserved.

903 Zone
This third mineralized zone present at Garrison was not included in the resource estimate reported by the previous operator in 2013. Mineralization at the 903 was discovered in 1945 by Wright-Hargreaves Mines Ltd. In 1988 Lac Minerals acquired the claims covering the current 903 Zone and completed 17 drill holes totaling 4,823 metres. The property was optioned in 1990 to Jonpol and T&H Resources and subsequently returned to Lac Minerals in 1991. Northern Gold acquired the claims from a subsidiary of Barrick Gold in 2013, conducting surface exploration and six drill holes.

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% in the high-grade Windfall Lake gold deposit located between Val-d’Or and Chibougamau in Québec and holds a 100% undivided interest in a large area of claims in the surrounding Urban Barry area, a 100% interest in the Marban project located in the heart of Québec’s prolific Abitibi gold mining district, and properties in the Larder Lake Mining Division in northeast Ontario, including the Garrcon, Jonpol and 903 zones on the Garrison property. Osisko continues to be well financed with approximately $190 million in cash and equity investments at the end of Q4 2017.

Cautionary Note Regarding Forward-Looking Information
This news release contains “forward-looking information” within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections and interpretations as at the date of this news release. The information in this news release about the ongoing drill program at the Garrison gold project; results of the current drill program; the significance of new drill results reported in this press release; the ability of new drill results to demonstrate potential for expansion of the previously defined Garrcon, Jonpol and 903 mineralized zones at the Garrison project; the scope of the 2017 drill program; that the 2017 drill program will follow new extensions of these mineralized zones to further define the scale of mineralization at the Garrison project; potential mineralization; the ability to realize upon any mineralization in a manner that is economic; the ability to complete any proposed exploration activities and the results of such activities; the continuity or extension of any mineralization; and any other information herein that is not a historical fact may be “forward-looking information”. Any statement that involves discussions with respect to predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often but not always using phrases such as “expects”, or “does not expect”, “is expected”, “interpreted”, “management’s view”, “anticipates” or “does not anticipate”,  “plans”, “budget”, “scheduled”, “forecasts”, “estimates”, “believes” or “intends” or variations of such words and phrases or stating that certain actions, events or results “may” or “could”, “would”, “might” or “will” be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This forward-looking information is based on reasonable assumptions and estimates of management of the Corporation, at the time it was made, involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Osisko to be materially different from any future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, risks relating to the ability of exploration activities (including drill results) to accurately predict mineralization; errors in management’s geological modelling; the ability of Osisko to complete further exploration activities, including drilling; property interests; the ability of the Corporation to obtain required approvals and complete transactions on terms announced; the results of exploration activities; risks relating to mining activities; the global economic climate; metal prices; dilution; environmental risks; and community and non-governmental actions. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, Osisko cannot assure shareholders and prospective purchasers of securities of the Corporation that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither Osisko nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. Osisko does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

For further information please contact:
John Burzynski, President and Chief Executive Officer
Telephone: (416) 363-8653

Osisko Mining Provides Ontario Exploration Update

(Toronto, February 13, 2018) Osisko Mining Inc. (OSK:TSX) (“Osisko” or the “Corporation”) is pleased to provide an update on the progress of exploration at its 100% owned Garrison gold project located in Garrison Township, Ontario.

Osisko has been conducting new exploration and definition drilling at Garrison for 20 months, since early 2016.  As of the end of January 2018, Osisko has completed 85,000 metres of new drilling to complement the pre-existing 108,000 metres drilled at Garrison by previous operators.  The company has re-evaluated previous drilling from the Jonpol Zone, continued resource delineation at the Garrcon Zone and substantially expanding the 903 Zone with exploration drilling in the southwest part of the property.  Dewatering and geological mapping of the Garrcon bulk sample pits was conducted during 2017.  Work is in progress on interpretation of the geological model of the Garrcon and 903 zones, including mineralization controls.

Exploration Budget for 2018:  $3M
Osisko’s 2018 exploration budget for the Garrison deposit totals approximately $3 million.  This includes resource estimation work, additional resource-oriented infill drilling, metallurgical work and exploration drilling on the Garrison property.

Garrison:  Updated Resource Estimation Planned for July 2018
Osisko’s updated resource estimate for the Garrison Project is scheduled to be released in July 2018. 

The Garrison property consists of three mineralized zones with different styles:  the Garrcon Zone is hosted by Temiskaming sediments in the footwall of the Destor Porcupine Fault Zone (PDFZ); the Jonpol Zone comprises 1.7 km of structurally controlled mineralization along the Munro Shear Zone hosted by mafic to ultramafic volcanic rocks; and the 903 Zone is hosted by syenite dykes intruding ultramafic rocks along the PDFZ.  The Jonpol and 903 zones remain open to the southwest and northwest respectively. The Garrcon, Jonpol and 903 zones will all be included in the 2018 updated resource.

Property Disposals
Through the course of 2017 Osisko vended the Catharine, DeSantis and Swayze exploration projects to other mining companies. 

President and CEO of Osisko John Burzynski commented: “Although our main focus is on the Windfall project in Québec, Osisko has continued work on the Garrison project, with the goal of updating the resource and improving our understanding of the potential of the Garrcon, Jonpol and 903 zones.  Drilling in 2017 was successful at significantly expanding the size of the 903 Zone.  Our upcoming July resource estimate will include all three zones (Garrcon, Jonpol and 903), and we will continue to evaluate the extensions of known mineralization with exploration drilling in 2018.” 

Qualified Person
The scientific and technical content of this press release has been reviewed, prepared and approved by Mr. Gernot Wober, P.Geo. VP Exploration Canada for Osisko Mining Inc, who is a “Qualified Person” as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”).

About the Garrison Project

The Garrison Project area is comprised of 214 mineral claims, 25 mining leases, and 87 patent claims encompassing approximately 8,000 hectares.  Both Garrcon and Jonpol have resource estimates that are described in a technical report prepared in accordance with NI 43-101, which was completed by a previous operator Northern Gold Mining Inc. (entitled “Technical Report on the Golden Bear Project – Garrison Property: Larder Lake Mining Division, Garrison Township, Ontario, Canada”) dated December 30, 2013, with an effective date of December 30, 2013 (the “Garrison Technical Report”). The Garrison Technical Report was prepared by A.C.A. Howe International Limited for Northern Gold Mining Inc. (a wholly-owned subsidiary of Osisko) and is available on Osiskos website at www.osiskomining.com and on SEDAR under Northern Gold Mining Inc.s issuer profile at www.sedar.com.

Resource estimates were conducted by A.C.A. Howe International Limited according to CIM standards. The Garrcon Zone estimates showed 15.1 million tonnes with an average grade of 1.07 g/t Au (521,000 oz) in measured resources; 14.1 million tonnes averaging 1.16 g/t Au (526,000 oz) in indicated resources; and 1.7 million tonnes averaging 0.72 g/t Au (39,000 oz) in inferred resources. Potential underground resources of 5.1 million tonnes averaging 3.49 g/t Au (577,000 oz) in the inferred category were also outlined. Resources were reported at a cut-off grade of 0.4 g/t Au for open pit extraction and 1.5 g/t in a bulk underground mining scenario using a gold price of US$1,250/oz.

At the Jonpol Zone, resources were estimated as 0.87 million tonnes averaging 5.34 g/t Au (150,000 oz) in the indicated category; and 1.07 million tonnes averaging 5.56 g/t Au (192,000 oz) in inferred resources. Resources were reported at a cut-off grade of 3.0 g/t Au and assume an underground extraction scenario using a gold price of US$1,250/oz.

Readers are cautioned that inferred resources have a great amount of uncertainty as to their existence and as to whether they can be mined economically. It cannot be assumed that all or any part of the inferred resources will ever be upgraded to a higher category. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

Garrcon Zone

The Garrcon Zone has a shallow plunge eastward along the footwall of the Destor-Porcupine Fault Zone with the bulk of the resource in the western, more densely drilled area. The zone is exposed at surface and has potential for open pit bulk mining at an estimated overall stripping ratio of 1.8:1. There is potential for additional underground resources below the pit and along the easterly plunge of the zone, which is open for further exploration down dip and along strike.

The Garrcon shaft was sunk in 1935 and 1936 by the Consolidated Mining and Smelting Co. of Canada (“Cominco”) and the Shaft and South Zones were tested for high grade gold mineralization. Cominco drove approximately 1,430 metres of drifts and cross cuts, mining underground veins. Diamond drilling by Cominco and Lac Minerals Ltd. in the mid-to-late 1980s identified broad sections of low grade mineralization. In 2006-2007, ValGold Resources Ltd. conducted additional drilling confirming these zones. From 2009-2013 Northern Gold Mining Inc. conducted 97,000 metres of diamond drilling which delineated the current resource.

In 2014, Northern Gold Mining Inc. was granted a trial mining permit allowing the extraction of up to 150,000 tonnes. Northern Gold Mining Inc. mined 73,534 dry tonnes which was processed at the nearby Holt mill facility recovering 3,516 oz at an average head grade of 1.55 g/t and recovery of 95.9%.

Jonpol Zone

Jonpol is situated in the Munro Fault Zone, a west striking splay off the north side of the Destor-Porcupine Fault. Hosted in a shear zone tens of metres wide in altered mafic volcanic rocks, the deposit consists of four high grade gold mineralized zones (JP, JD, RP and East) over a strike length of 1.7 kilometers. Gold mineralization is hosted in quartz carbonate veins, in mafic and ultramafic host rocks, and is associated with intense albite and/or sericite alteration and pyrite mineralization.

In 1997, a 49,087 tonne bulk sample was extracted from the central part of the JP zone by Hillsborough Resources Limited with an average grade of 6.7 g/t which produced 9,476 ounces Au. From 1985-2013, over 130,000 metres of drilling was completed on the property by previous operators. Development work on the JP zone included the sinking of a 184 metre shaft as well as development of a ramp to the 150 metres level with mining on six sublevels. The Jonpol infrastructure underwent reclamation in the late 1990s and was closed out in 2001, but the existing ramp and shaft are preserved.

903 Zone

This third mineralized zone present at Garrison was not included in the resource estimate reported by the previous operator in 2013. Mineralization at the 903 was discovered in 1945 by Wright-Hargreaves Mines Ltd. In 1988 Lac Minerals acquired the claims covering the current 903 Zone and completed 17 drill holes totaling 4,823 metres. The property was optioned in 1990 to Jonpol and T&H Resources and subsequently returned to Lac Minerals in 1991. Northern Gold acquired the claims from a subsidiary of Barrick Gold in 2013, conducting surface exploration and six drill holes.

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% in the high-grade Windfall Lake gold deposit located between Val-dOr and Chibougamau in Québec and holds a 100% undivided interest in a large area of claims in the surrounding Urban Barry area and nearby Quévillon area (over 3,300 square kilometres), a 100% interest in the Marban project located in the heart of Québecs 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 Québec and Ontario.  Osisko continues to be well financed with approximately $190 million in cash and investments as of the end of Q4 2017.

Cautionary Note Regarding Forward-Looking Information
This news release contains “forward-looking information” within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections and interpretations as at the date of this news release. The information in this news release about the timing and ability (if at all) of Osisko to prepare a Preliminary Economic Assessment and initial resource estimate for the Windfall deposit; the timing and ability (if at all) of Osisko to prepare a feasibility study for the Windfall deposit; Osiskos exploration budget for 2018; the advancement of the Windfall and Lynx deposits through drilling and exploration initiatives; the expansion of the previously known mineralized zones and the discovery of the new Lynx deposit, and Wolf and Bobcat zones; continued exploration and drilling at the Windfall and Lynx deposits and any extension of the mineralized zones; the continued advancement, and rate of advancement, of the exploration ramp; the timing and ability (if at all) of Osisko to obtain permits for the exploration ramp towards Lynx; the ability of the Windfall Lake gold project to be one of the highest-grade resource stage gold projects in Canada; the significance of drill results from the ongoing drill program at the Windfall Lake gold project; the timing and ability (if at all) of Osisko to complete additional property acquisitions in Lebel-sur-Quévillon; the benefits of a potential processing plant in Lebel-sur-Quévillon; the timing and ability (if at all) of Osisko to prepare  an initial resource estimate in respect of the Osborne-Bell deposit; exploration planned at the Fox and Black Dog discoveries; proposed exploration work at the Urban Barry block; proposed exploration work on the Quévillon block; the continued fast pace of our work in 2018; our ability to sustain and add shareholder value; Osiskos ability (if at all) to develop into a mining camp; the type of drilling included in the drill program; potential mineralization; the ability to realize upon any mineralization in a manner that is economic; the ability to complete any proposed exploration activities and the results of such activities; and any other information herein that is not a historical fact may be “forward-looking information”. Any statement that involves discussions with respect to predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often but not always using phrases such as “expects”, or “does not expect”, “is expected”, “interpreted”, “managements view”, “anticipates” or “does not anticipate”, “plans”, “budget”, “scheduled”, “forecasts”, “estimates”, “believes” or “intends” or variations of such words and phrases or stating that certain actions, events or results “may” or “could”, “would”, “might” or “will” be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This forward-looking information is based on reasonable assumptions and estimates of management of the Corporation at the time it was made. This forward-looking information involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements to be materially different from any results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, risks relating to the ability of exploration activities to accurately predict mineralization; errors in managements geological modelling; delays in the turnaround of assay data; lack of adequate drill density; Osiskos timing and ability (if at all) to complete further exploration activities, including drilling; property interests in the Windfall Lake gold project and Osborne-Bell gold deposit; the results of exploration activities; risks relating to mining activities; the global economic climate; metal prices; dilution; environmental risks; and community and non-governmental actions. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, Osisko cannot assure shareholders and prospective purchasers of securities of the Corporation that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither Osisko nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. Osisko does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

For further information please contact:
John Burzynski. President and Chief Executive Officer
Telephone: (416) 363-8653

Osisko Mining Provides Quebec Exploration Update

(Toronto, February 8, 2018)  Osisko Mining Inc. (OSK:TSX) (“Osisko” or the “Corporation”) is pleased to provide an update on the progress of exploration at its 100% owned Windfall Lake, Urban Barry and Quévillon gold projects located in the Abitibi greenstone belt, Eeyou Istchee James Bay, Québec.

Osisko has been conducting new exploration and definition drilling at Windfall for 26 months, since late October 2015.  As of the end of January 2018, Osisko has completed 518,000 metres of the planned 800,000 metres to complement the pre-existing 180,000 metres drilled at Windfall by previous operators. 

The company is rapidly advancing the Windfall and Lynx deposits through a balance of resource delineation drilling and exploration drilling for extensions and new mineralized zones.  Osisko has been successful in the past two years at significantly expanding the known areas of mineralization in the Windfall system and reinterpreting the geological model of the Windfall deposit.  Drilling over the past 18 months has been directed by the evolving intrusion-related geological model, leading to the discovery of significant extensions of the previously known mineralized zones, and to the discovery of the new Lynx deposit, Wolf and Bobcat zones.

Exploration Budget for 2018:  $100M
Osisko’s 2018 exploration budget for the Windfall/Lynx deposits, Urban Barry and Quévillon project areas totals approximately $100 million.  This budget includes resource estimation work, resource-oriented drilling, exploration ramp and underground bulk sampling of known mineralized zones, metallurgical work, permitting, PEA and feasibility studies, exploration drilling proximal to Windfall and Lynx, and exploration drilling on the greater Urban Barry and Quévillon properties.

Windfall/Lynx:  Initial Resource Estimation Planned for May 2018, PEA Planned for June 2018
Osisko’s initial resource for Windfall is scheduled to be released in early May, a delay of six weeks from the previous Q1 2018 estimated completion, due to the slower than anticipated turnaround of assay data.  Osisko plans to have a Preliminary Economic Assessment completed in June 2018 for the Windfall deposit subsequent to the release of the initial resource estimate.

The main Windfall deposit and the Lynx deposit (discovered by Osisko in early 2017) remain open to the NE and at depth, and surface exploration drilling is continuing.  Newly discovered extensions of the main Windfall deposit (Caribou Extension, Zone 27 Extension, Underdog Expansion), and part of the Lynx deposit and its sub zones below 350 metres depth and further northeast of section 3750E, will not be included in the May 2018 resource estimate, due to lack of adequate drill density.  Infill drilling planned for the balance of 2018 will be focused on these areas, with the aim of including them in a planned Q1 2019 feasibility study.

The Corporation will continue significant exploration drilling at Windfall and Lynx through the balance of 2018 as it moves towards the feasibility study, and will continue drilling at the main Windfall and Lynx deposit to infill and extend the mineralized zones defined to date.

Windfall Exploration Ramp Progress
Dewatering of the historic exploration ramp was completed at the end of August 2017, and rehabilitation of the portal began in September. To date, 1,021 metres of rehabilitation have been completed. The remaining areas of the pre-existing exploration ramp are non-essential and will be rehabilitated as necessary.

The first underground blast was completed in late October (see October 27, 2017 press release). Underground infrastructure completed to date includes 45 metres of development for powder and cap magazines and 48 metres of slashes and safety bays. Three electrical substations have been installed as well as a water basin for future water treatment.

New advance towards the Main Zone commenced in late December, with 136 metres completed to date. The rate of advance is approximately 150 metres per month.  Bulk sampling in Zone 27, Caribou and Underdog is anticipated to occur in Q2 2018, Q3 2018 and Q4 2019 respectively.

Permits for the exploration ramp towards Lynx are anticipated in Q2 2018. Approximately 1,200 metres of exploration ramp extension are planned to reach Lynx.  Bulk sampling in Lynx is anticipated to occur in Q1 2019.

Property Acquisition in Lebel-sur-Quévillon
An alternatives assessment, considering environmental, technical, social and economic factors, has been completed on the location of the potential processing plant for the Windfall Project. The preferred option for the location of the potential processing plant is in the municipality of Lebel-sur-Quévillon (partially on the former Domtar site) and in the territory of Eeyou Istchee James Bay, Québec. The acquisition of approximately 560 hectares of property is expected to be finalized in Q1 2018. The proximity to a stable workforce and existing infrastructure, including power and water supply with available capacity were important components in the evaluation.

Osborne-Bell:  Initial Resource Estimation Planned for April 2018
Osisko commenced new drilling at the Osborne-Bell deposit with two rigs in early December 2017.  Re-evaluation of the approximately 200,000 metres of historical drilling results from previous operators and the addition of new information from Osisko’s drilling will be used to produce an initial resource, anticipated to be released in early April 2018.  Osborne-Bell is located approximately 20 kilometres northwest of the town of Lebel-sur-Quévillon.

Exploration Planned for Fox and Black Dog
A review of the exploration work conducted by Osisko in 2016 and 2017 at the Fox and Black Dog discoveries, within the context of the evolving geological model for the main Windfall deposit is currently under way.  New exploration drilling is planned for the two areas in H2 2018.

Exploration on the Urban Barry Block
Osisko has completed base line exploration programs on the Urban Barry block including airborne geophysics, ground geophysics, geological mapping and sampling and basal till sampling, developing a significant number of targets (over 100).  Osisko intends to include exploration drilling on priority targets developed by these base line programs in the course of 2018 work.

Exploration on the Quévillon Block
Osisko acquired the Quévillon Block in early 2017, and commenced the collection of base line exploration data including airborne geophysics, geological mapping and sampling, and basal till sampling.  The continuing work is approximately one-third complete, with several significant exploration targets already developed from both historical drilling and the new information collected.  Osisko intends to include exploration drilling on priority targets developed by these programs in the course of 2018 work.

President and CEO of Osisko John Burzynski commented: “We have been moving the Windfall project forward at a very quick pace since our first work started in late 2015.  We have added significant shareholder value through our substantial drilling and exploration programs at Windfall, with the discovery of the Lynx deposit and new previously unknown extensions of the main Windfall zones.  We plan to continue the fast pace of work on all of our projects in 2018 with over 20 active drills, and are eagerly anticipating the release of our first resource estimate for Windfall-Lynx in early May.  We will prepare a Preliminary Economic Assessment for Windfall-Lynx for June 2018 following the anticipated resource estimate, and will continue our exploration of the deposits through surface drilling and the progression of the exploration ramp, with the goal of moving to a feasibility study for Windfall in early 2019.  Property-wide exploration on our bank of existing targets will also resume in 2018, with the goal of adding new discoveries to our growing inventory of “drill bit success” at Windfall.  We will have another very busy year, with an exploration budget of approximately $100 million, and will continue to be the most active explorer in Québec in what we believe is a new developing mining camp.”

About the Windfall Lake Gold Deposit
The Windfall Lake gold deposit is located between Val-dOr and Chibougamau in the Abitibi region of Québec, Canada. The mineral resource defined by the previous operator 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, Québec, 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% in the high-grade Windfall Lake gold deposit located between Val-dOr and Chibougamau in Québec and holds a 100% undivided interest in a large area of claims in the surrounding Urban Barry area and nearby Quévillon area (over 3,300 square kilometres), a 100% interest in the Marban project located in the heart of Québecs 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 Québec and Ontario.  Osisko continues to be well financed with approximately $190 million in cash and investments as of the end of Q4 2017.

Cautionary Note Regarding Forward-Looking Information
This news release contains “forward-looking information” within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections and interpretations as at the date of this news release. The information in this news release about the timing and ability (if at all) of Osisko to prepare a Preliminary Economic Assessment and initial resource estimate for the Windfall deposit; the timing and ability (if at all) of Osisko to prepare a feasibility study for the Windfall deposit; Osiskos exploration budget for 2018; the advancement of the Windfall and Lynx deposits through drilling and exploration initiatives; the expansion of the previously known mineralized zones and the discovery of the new Lynx deposit, and Wolf and Bobcat zones; continued exploration and drilling at the Windfall and Lynx deposits and any extension of the mineralized zones; the continued advancement, and rate of advancement, of the exploration ramp; the timing and ability (if at all) of Osisko to obtain permits for the exploration ramp towards Lynx; the ability of the Windfall Lake gold project to be one of the highest-grade resource stage gold projects in Canada; the significance of drill results from the ongoing drill program at the Windfall Lake gold project; the timing and ability (if at all) of Osisko to complete additional property acquisitions in Lebel-sur-Quévillon; the benefits of a potential processing plant in Lebel-sur-Quévillon; the timing and ability (if at all) of Osisko to prepare  an initial resource estimate in respect of the Osborne-Bell deposit; exploration planned at the Fox and Black Dog discoveries; proposed exploration work at the Urban Barry block; proposed exploration work on the Quévillon block; the continued fast pace of our work in 2018; our ability to sustain and add shareholder value; Osiskos ability (if at all) to develop into a mining camp; the type of drilling included in the drill program; potential mineralization; the ability to realize upon any mineralization in a manner that is economic; the ability to complete any proposed exploration activities and the results of such activities; and any other information herein that is not a historical fact may be “forward-looking information”. Any statement that involves discussions with respect to predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often but not always using phrases such as “expects”, or “does not expect”, “is expected”, “interpreted”, “managements view”, “anticipates” or “does not anticipate”, “plans”, “budget”, “scheduled”, “forecasts”, “estimates”, “believes” or “intends” or variations of such words and phrases or stating that certain actions, events or results “may” or “could”, “would”, “might” or “will” be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This forward-looking information is based on reasonable assumptions and estimates of management of the Corporation at the time it was made. This forward-looking information involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements to be materially different from any results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, risks relating to the ability of exploration activities to accurately predict mineralization; errors in managements geological modelling; delays in the turnaround of assay data; lack of adequate drill density; Osiskos timing and ability (if at all) to complete further exploration activities, including drilling; property interests in the Windfall Lake gold project and Osborne-Bell gold deposit; the results of exploration activities; risks relating to mining activities; the global economic climate; metal prices; dilution; environmental risks; and community and non-governmental actions. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, Osisko cannot assure shareholders and prospective purchasers of securities of the Corporation that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither Osisko nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. Osisko does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

For further information please contact:
John Burzynski. President and Chief Executive Officer
Telephone: (416) 363-8653