OSISKO INTERSECTS 115 g/t Au OVER 8.4 METRES AT LYNX

Infill Drilling Continues to Encounter High-Grade Gold

 (Toronto, April 26, 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 Township, 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 19 intercepts in 12 drill holes and 5 wedges focused on infill drilling in the Lynx deposit are presented below. Today’s infill drilling results will not be included in the pending mineral resource scheduled for release in May 2018.

Highlights from the new results include: 115 g/t Au over 8.4 metres in OSK-W-17-1363; 58.7 g/t Au over 5.1 metres in OSK-W-17-1343-W1; 118 g/t Au over 2.5 metres and 85.1 g/t Au over 2.0 metres in OSK-W-17-1169-W2; 72.8 g/t Au over 3.1 metres in OSK-W-17-1166; 68.8 g/t Au over 2.0 metres in OSK-W-17-928; 67.0 g/t Au over 2.0 metres in OSK-W-17-1396; 50.3 g/t Au over 2.3 metres in OSK-W-17-986; and 43.0 g/t Au over 2.6 metres in OSK-W-17-1320. 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-17-928 247.0 249.0 2.0 68.8 50 Lynx HW Lynx
including 247.0 248.0 1.0 138 100
OSK-W-17-986 337.7 340.0 2.3 50.3 48.7 VNCR Lynx
including 338.4 339.5 1.1 104 100
OSK-W-17-1166 973.0 976.1 3.1 72.8 14.9 Lynx 4 Lynx
including 974.4 974.8 0.4 549 100
OSK-W-17-1320 90.4 93.0 2.6 43.0 15.6 Vein Lynx
including 91.3 91.7 0.4 278 100
OSK-W-17-1343-W1 596.7 601.8 5.1 58.7 30.3 Lynx HW Lynx
including 597.7 599.0 1.3 212 100
OSK-W-17-1363 373.6 382.0 8.4 115 24.0 Lynx 2 Lynx
including 377.0 377.7 0.7 1190 100
including 379.0 380.0 1.0 97.7
OSK-W-17-1396 873.0 875.0 2.0 67.0 15.3 Lynx 4 Lynx
including 873.8 874.1 0.3 445 100
OSK-W-18-1169-W1 564.0 566.1 2.1 7.84   Lynx 2 Lynx
OSK-W-18-1169-W2 908.1 910.6 2.5 118 49.7 Lynx 4 Lynx
including 908.4 909.0 0.6 386 100
  925.0 927.0 2.0 4.09   Lynx 4 Lynx
  1082.0 1084.0 2.0 85.1 46.9 Lynx 4 Lynx
including 1082.3 1083.2 0.9 185 100
OSK-W-18-1367-W2 878.0 882.0 4.0 4.55   Lynx Lynx
OSK-W-18-1424 878.2 880.7 2.5 4.24   Lynx 4 Lynx
including 879.1 879.9 0.8 12.2
OSK-W-18-1432-W1 944.0 946.5 2.5 8.89   Lynx 4 Lynx
OSK-W-18-1443 584.0 586.0 2.0 4.25   Lynx HW Lynx
including 584.4 585.0 0.6 13.7
OSK-W-18-1450 565.1 567.3 2.2 36.7   Lynx 2 Lynx
OSK-W-18-1454 896.1 898.7 2.6 17.0 16.4 Lynx 4 Lynx
including 896.1 896.5 0.4 104 100
OSK-W-18-1455 441.0 443.0 2.0 4.12   Lynx HW Lynx
including 441.3 442.0 0.7 10.5
OSK-W-18-1460 332.0 337.4 5.4 4.50   Lynx HW Lynx
including 332.0 332.5 0.5 20.3
including 337.0 337.4 0.4 28.5

Notes:   True widths are estimated at 65 – 80% of the reported core length interval.  See “Quality Control” below.
Definitions: HW = Hanging Wall; VNCR = Crustiform Vein.

 

Hole Number Azimuth

(°)

Dip

(°)

Length

(m)

UTM E UTM N Section
OSK-W-17-928 333 -64 465 453433 5434905 3550
OSK-W-17-986 328 -66 360 453447 5435019 3600
OSK-W-17-1166 132 -59 1182 453621 5435639 4050
OSK-W-18-1169-W1 129 -55 1301 453332 5435467 3725
OSK-W-18-1169-W2 129 -55 1155 453332 5435467 3725
OSK-W-17-1320 328 -76 852 452906 5434846 3050
OSK-W-17-1343-W1 137 -56 870 453570 5435490 3950
OSK-W-17-1363 341 -72 513 453458 5435025 3625
OSK-W-18-1367-W2 131 -52 1224 453753 5435875 4300
OSK-W-17-1396 134 -52 956 453439 5435484 3825
OSK-W-18-1424 357 -57 930 453357 5434365 3200
OSK-W-18-1432-W1 132 -55 1149 453809 5435783 4300
OSK-W-18-1443 136 -50 792 453440 5435478 3825
OSK-W-18-1450 135 -53 660 453384 5435519 3800
OSK-W-18-1454 145 -53 1089 453375 5435455 3750
OSK-W-18-1455 140 -49 552 453568 5435492 3950
OSK-W-18-1460 143 -51 432 453468 5435347 3775

 

OSK-W-17-928 intersected 68.8 g/t Au over 2.0 metres in Lynx HW. Mineralization contains trace disseminated pyrite within a moderate sericite and weak silica altered rhyolite.

OSK-W-17-986 intersected a crustiform vein returning 50.3 g/t Au 2.3 metres. Mineralization contains local visible gold, 2% pyrite stringers, 2% crustiform quartz-carbonate veins and pyrite-silica flooding within a silica, carbonate and fuchsite altered gabbro.

OSK-W-17-1166 intersected 72.8 g/t Au over 3.1 metres in Lynx 4. Mineralization contains local visible gold, 10% pyrite-silica flooding and 3% pyrite-tourmaline stringers within a porphyritic felsic dike.

OSK-W-17-1320 intersected 43.0 g/t Au over 2.6 metres in Lynx. Mineralization contains 1% disseminated pyrite and trace pyrite in quartz veins within in a strong chlorite, moderate silica and weak sericite altered porphyritic felsic dike.

OSK-W-17-1343-W1 intersected 58.7 g/t Au over 5.1 metres in Lynx HW. Mineralization contains 3% pyrite-silica flooding, 1% pyrite-tourmaline stringers and a 10 centimetres quartz vein within a strong silica and moderate sericite altered porphyritic felsic dike.

OSK-W-17-1363 intersected 115 g/t Au over 8.4 metres in Lynx 2. Mineralization contains local visible gold and electrum and up to 25% disseminated pyrite or pyrite-tourmaline stringers within strong pervasive silica flooding. The gabbro host is strongly fuchsite and silica altered.

OSK-W-17-1396 intersected 67.0 g/t Au over 2.0 metres in Lynx 4. Mineralization contains 1% pyrite in quartz-tourmaline veins and 3% disseminated pyrite within a moderate sericite, moderate fuchsite and weak silica altered rhyolite.

OSK-W-18-1169-W1 intersected 7.84 g/t Au over 2.1 metres in Lynx 2. Mineralization contains 2% pyrite disseminated or as stringers and 10% quartz-carbonate and tourmalines veins within a silica and fuchsite altered gabbro.

OSK-W-18-1169-W2 intersected three intervals in Lynx 4: 118 g/t Au over 2.5 metres, 4.09 g/t Au over 2.0 metres and 85.1 g/t Au over 2.0 metres. The first interval contains local visible gold, up to 15% pyrite-tourmaline stringers and 1% disseminated pyrite within strong pervasive silica alteration at the contact between a silicified and sericitized gabbro and a sericitized rhyolite. The second interval contains local visible gold and 10% pyrite in smoky-quartz veins within a sericite altered rhyolite. The third interval contains local visible gold and 5% pyrite-tourmaline stringers within a strong silica, moderate sericite, moderate ankerite and weak fuchsite altered rhyolite.

OSK-W-18-1367-W2 intersected 4.55 g/t Au over 4.0 meters in Lynx Corridor. Mineralization contains 1% pyrite clusters and trace pyrite-silica flooding within a moderate chlorite and weak silica altered rhyolite.

OSK-W-18-1424 intersected 4.24 g/t Au over 2.5 metres in Lynx 4. Mineralization contains up to 2% pyrite-tourmaline and 1% pyrite in quartz-carbonate veins within a sericitized zone at the contact between a porphyritic felsic dike and a rhyolite.

OSK-W-18-1432-W1 intersected 8.89 g/t Au over 2.5 metres in Lynx 4. Mineralization contains up to 15% pyrite stringers at low core angles, 2% disseminated pyrite and traces of pyrite in ptygmatic tourmaline veins at the contact between a sericitized porphyritic felsic dike and a strongly bleached gabbro.

OSK-W-18-1443 intersected 4.25 g/t Au over 2.0 metres in Lynx HW. Mineralization contains 10% disseminated pyrite and trace pyrite clusters within a bleached, chloritized and silicified gabbro.

OSK-W-18-1450 intersected 36.7 g/t Au over 2.2 metres in Lynx 2. Mineralization contains up to 8% pyrite-silica flooding within a strong silica and weak sericite altered gabbro.

OSK-W-18-1454 intersected 17.0 g/t Au over 2.6 metres in Lynx 4. Mineralization is composed of 2% disseminated pyrite and quartz-tourmaline veins, and 1% pyrite-tourmaline stringers within a strong sericite altered rhyolite.

OSK-W-18-1455 intersected 4.12 g/t Au over 2.0 metres in Lynx HW. Mineralization contains up to 4% disseminated pyrite, up to 2% pyrite stringers and trace pyrite clusters at the contact between a fuchsite altered gabbro and a felsic porphyritic dike.

OSK-W-18-1460 intersected 4.50 g/t Au over 5.4 metres in Lynx HW. Mineralization contains 2% pyrite-silica flooding and 1% disseminated pyrite at the contact between a strong silica altered rhyolite and a felsic intrusion.

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 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; 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 41.2 g/t Au OVER 3.5 METRES AT WINDFALL

Additional High-Grade Infill Holes in Caribou, Underdog and Bobcat

(Toronto, April 19, 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 Township, 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 46 intercepts in 23 drill holes and 5 wedges focused on infill drilling in the Main Windfall lake deposit are presented below. Today’s infill drilling results will not be included in the pending mineral resource scheduled for release in May 2018.

Highlights from the new results include: 82.5 g/t Au over 2.0 metres in OSK-W-17-1391; 41.2 g/t Au over 3.5 metres in OSK-W-18-1402-W3; 34.3 g/t Au over 2.6 metres in OSK-W-18-1435; 31.4 g/t Au over 2.7 metres in OSK-W-18-1440; 5.53 g/t Au over 11.9 metres in OSK-W-17-801; and 24.0 g/t Au over 2.4 metres in OSK-W-17-1409. 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-EAG-12-333 787.0 789.0 2.0 5.38 FW3 Underdog
including 787.8 788.1 0.3 34.7
OSK-EAG-12-424 832.6 835.1 2.5 6.72 FW3 Underdog
OSK-W-17-801 688.1 691.0 2.9 7.75 Caribou Ext. Caribou
  697.0 699.4 2.4 3.70 Caribou Ext. Caribou
  758.5 770.4 11.9 5.53 Caribou Ext. Caribou
including 758.5 762.0 3.5 10.6
  777.0 781.4 4.4 3.92 Caribou Ext. Caribou
OSK-W-17-1371 722.1 724.6 2.5 3.96 Vein Wolf
including 724.0 724.6 0.6 15.6
OSK-W-17-1378 229.9 232.0 2.1 4.41 Caribou Caribou
  336.9 339.4 2.5 5.36 Caribou Caribou
OSK-W-17-1379 485.0 487.3 2.3 3.03 Caribou Ext. Caribou
OSK-W-17-1391 501.0 503.0 2.0 82.5 35.6 Vein Caribou
including 501.0 501.7 0.7 234 100
OSK-W-17-1394 780.5 782.6 2.1 4.25 Caribou Ext. Caribou
including 781.0 781.6 0.6 14.7
OSK-W-17-1397 639.0 641.0 2.0 3.53 VNCR Caribou
  711.0 713.2 2.2 3.69 Vein Caribou
OSK-W-17-1399 658.5 661.0 2.5 4.45 Caribou Ext. Caribou
OSK-W-17-1406 117.0 119.0 2.0 7.28 Vein Bobcat
including 117.0 118.0 1.0 13.8
  129.0 131.0 2.0 6.91 QTV Bobcat
including 129.4 130.3 0.9 15.2
OSK-W-17-1409 133.3 135.7 2.4 24.0 13.6 Bobcat Bobcat
including 135.4 135.7 0.3 184 100
  205.0 207.0 2.0 6.11 Bobcat Bobcat
including 205.4 206.0 0.6 19.5
  350.0 352.4 2.4 7.17 Caribou Ext. Caribou
including 351.0 351.5 0.5 34.1
OSK-W-18-1066-W1 944.4 946.4 2.0 12.9 FW3 Underdog
including 945.0 945.7 0.7 36.0
  1008.2 1010.4 2.2 21.0 FW3 FW Underdog
including 1008.8 1009.1 0.3 81.6
OSK-W-18-1402-W1 826.5 833.1 6.6 4.07 FW1 Underdog
OSK-W-18-1402-W3 778.0 780.3 2.3 8.11 FW0 Underdog
including 779.2 779.7 0.5 25.5
  821.1 824.6 3.5 6.21 FW1 Underdog
  880.0 882.0 2.0 4.98 FW1 FW Underdog
including 881.0 881.7 0.7 12.3
  888.5 892.0 3.5 41.2 FW1 FW Underdog
including 888.5 890.0 1.5 65.9
  1104.7 1109.4 4.7 9.36 FW3 Underdog
including 1104.7 1105.1 0.4 35.4
including 1109.1 1109.4 0.3 96.1
OSK-W-18-1423 509.8 512.0 2.2 5.63 Caribou Ext. Caribou
including 509.8 510.5 0.7 17.3
OSK-W-18-1430 707.5 709.5 2.0 7.91 FW1 Underdog
including 708.3 708.9 0.6 23.1
OSK-W-18-1430-W1 818.0 821.0 3.0 4.95 FW2 Underdog
OSK-W-18-1431 1070.0 1072.0 2.0 5.73 FW4 Underdog
OSK-W-18-1431-W1 758.0 760.3 2.3 3.06 FW1 Underdog
  967.8 969.9 2.1 13.5 FW3 FW Underdog
including 969.2 969.9 0.7 28.0
OSK-W-18-1434 859.5 864.2 4.7 11.6 FW3 Underdog
including 859.5 860.0 0.5 63.4
including 863.8 864.2 0.4 45.5
  960.0 962.4 2.4 16.0 FW3U Underdog
including 962.0 962.4 0.4 68.7
OSK-W-18-1435 532.0 534.6 2.6 34.3 24.7 Caribou Ext. Caribou
including 533.3 533.9 0.6 142 100
  539.0 541.0 2.0 4.38 Caribou Ext. Caribou
including 540.2 540.5 0.3 29.0
OSK-W-18-1440 729.3 732.0 2.7 31.4 26.7 FW1 Underdog
including 730.3 731.0 0.7 118 100
OSK-W-18-1441 181.0 187.6 6.6 8.06 Bobcat Bobcat
OSK-W-18-1445 531.9 535.4 3.5 5.75 Caribou Ext. Caribou
OSK-W-18-1446 679.0 682.2 3.2 10.8 FW1 Underdog
including 680.2 680.8 0.6 32.6
  761.0 763.0 2.0 4.27 FW2 Underdog
including 761.7 762.4 0.7 12.1
  794.6 796.8 2.2 4.05 FW3 Underdog
including 795.2 796.0 0.8 11.0
OSK-W-18-1448 263.0 265.0 2.0 6.02 Caribou Caribou
OSK-W-18-1459 180.0 182.0 2.0 8.26 VNCR Bobcat

Notes:

  1. True widths are estimated at 65 – 80% of the reported core length interval. See “Quality Control”
  2. Definitions: Ext = extension, FW = Footwall, QTV = Quartz-Tourmaline Vein, U = Upper, VNCR = Crustiform Vein

 

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Section
OSK-EAG-12-333 333 -58 983 452459 5434565 2525
OSK-EAG-12-424 330 -55 1003 452598 5434580 2650
OSK-W-17-801 333 -69 840 453192 5434907 3325
OSK-W-17-1371 334 -69 981 453100 5434875 3225
OSK-W-17-1378 331 -56 741 452688 5434638 2750
OSK-W-17-1379 332 -66 540 452781 5434772 2900
OSK-W-17-1391 327 -62 663 452981 5434900 3150
OSK-W-17-1394 335 -49 1165 453146 5434512 3100
OSK-W-17-1397 333 -61 732 453300 5434964 3450
OSK-W-17-1399 332 -61 1053 453411 5434870 3500
OSK-W-17-1406 334 -60 579 452911 5434879 3075
OSK-W-17-1409 331 -53 402 452747 5434881 2925
OSK-W-18-1066-W1 332 -56 1137 452488 5434436 2475
OSK-W-18-1402-W1 330 -59 1224 452616 5434449 2600
OSK-W-18-1402-W3 330 -59 1182 452616 5434449 2600
OSK-W-18-1423 327 -61 792 453025 5434853 3150
OSK-W-18-1430 339 -60 984 452318 5434380 2300
OSK-W-18-1430-W1 339 -60 1125 452318 5434380 2300
OSK-W-18-1431 337 -62 1128 452287 5434336 2250
OSK-W-18-1431-W1 337 -62 1092 452287 5434336 2250
OSK-W-18-1434 335 -55 1026 452452 5434496 2475
OSK-W-18-1435 331 -65 801 453028 5434848 3150
OSK-W-18-1440 329 -57 870 452418 5434448 2425
OSK-W-18-1441 328 -60 441 452886 5434912 3075
OSK-W-18-1445 337 -66 660 452892 5434867 3050
OSK-W-18-1446 335 -48 987 452257 5434332 2225
OSK-W-18-1448 333 -52 483 452688 5434808 2850
OSK-W-18-1459 132 -50 621 452860 5435186 3175

OSK-EAG-12-333 intersected 5.38 g/t Au over 2.0 metres in FW3. Mineralization is composed of 7% pyrite-silica flooding and up to 1% pyrite stringers within a strong silica, weak sericite altered felsic porphyritic dike.

OSK-EAG-12-424 intersected 6.72 g/t Au over 2.5 metres in FW3. Mineralization is composed of up to 5% pyrite stringers, 1% pyrite clusters and quartz veins within a moderate sericitized felsic porphyritic dike.

OSK-W-17-801 intersected four intervals in Caribou Extension: 7.75 g/t Au over 2.9 metres, 3.70 g/t Au over 2.4 metres, 5.53 g/t Au over 11.9 metres and 3.92 g/t Au over 4.4 metres. The first and second intervals are composed of up to 5% pyrite stringers and semi-massive pyrite within a strong sericite altered andesite. In the third and fourth intervals, mineralization is composed of up to 3% pyrite stringers, 3% pyrite clusters and 1% disseminated pyrite at the contact between a strong chlorite altered andesite and a strong sericite altered felsic porphyritic dike. These two intervals are 100 metres down plunge of OSK-W-17-1351 (3.65 g/t Au over 2.2 metres and 3.64 g/t Au over 2.3 metres previously reported January 18, 2018).

OSK-W-17-1371 intersected 3.96 g/t Au over 2.5 metres in Wolf. Mineralization is hosted in a quartz vein and composed of up to 2% disseminated pyrite within a strong chlorite altered andesite.

OSK-W-17-1378 intersected two intervals in Caribou: 4.41 g/t Au over 2.1 metres and 5.36 g/t Au over 2.5 metres. The first interval is composed of 1% pyrite stringers within strong chlorite, and weak fuchsite altered felsic porphyritic dike. The second interval is composed of trace disseminated or stringer pyrite  and quartz-tourmaline veins within a strong chlorite altered andesite.

OSK-W-17-1379 intersected 3.03 g/t Au over 2.3 metres in Caribou Extension. Mineralization is composed of trace pyrite stringer and chalcopyrite within a felsic porphyritic dike.

OSK-W-17-1391 intersected 82.5 g/t Au over 2.0 metres in Caribou. Mineralization is composed of 1% pyrite stringers and quartz vein within a chloritized andesite.

OSK-W-17-1394 intersected 4.25 g/t Au over 2.1 metres in Caribou Extension. Mineralization is composed of 2% pyrite stringers, 1% disseminated pyrite within a strong sericite altered rhyolite.

OSK-W-17-1397 intersected two veins in Caribou returning 3.53 g/t Au over 2.0 metre and 3.69 g/t Au over 2.2 metres. Both intersects are composed of up to 15% disseminated pyrite hosted in quartz veins within a strong silica, strong sericite and moderate chlorite altered rhyolite.

OSK-W-17-1399 intersected 4.45 g/t Au over 2.5 metres in Caribou Extension. Mineralization is composed of 2% pyrite clusters and quartz veins within a weak sericite altered rhyolite layered with gabbro.

OSK-W-17-1406 intersected two intervals in Bobcat: 7.28 g/t Au over 2.0 metres and 6.91 g/t Au over 2.0 metres. Both intersects are composed of up to 4% disseminated pyrite and quartz-tourmaline crustiform veins within a weak sericite altered gabbro.

OSK-W-17-1409 intersected three intervals: 24.0 g/t Au over 2.4 metres and 6.11 g/t Au over 2.0 metres in Bobcat and 7.17 g/t Au over 2.4 metres in Caribou Extension. The first two intervals are composed of trace disseminated and stringer pyrite and quartz-tourmaline veins within a strong sericite and silica altered rhyolite. The last interval is composed of trace disseminated pyrite and quartz-tourmaline veins within a strong chlorite and weak sericite altered rhyolite.

OSK-W-18-1066-W1 intersected two intervals: 12.9 g/t Au over 2.0 metres in FW3 and 21.0 g/t Au over 2.2 metres in FW3 Footwall. The first interval is composed of 35% semi-massive pyrite within a strong sericite altered felsic porphyritic dike. The second interval is composed of 10% pyrite stringers and pyrite-silica flooding within a moderate sericite altered felsic porphyritic dike.

OSK-W-18-1402-W1 intersected 4.07 g/t Au over 6.6 metres in FW1. Mineralization is composed of up to 2% pyrite in stockwork and stringers within a strong sericite altered felsic porphyritic dike.

OSK-W-18-1402-W3 intersected five intervals: 8.11 g/t Au over 2.3 metres in FW0, 6.21 g/t Au over 3.5 metres in FW1, 4.98 g/t Au over 2.0 metres and 41.2 g/t Au over 3.5 metres in FW1 FW, and 9.36 g/t Au over 4.7 metres in FW3. The first interval is composed of up to 15% pyrite in pyrite-silica flooding, stringers and disseminated within a strong sericite altered felsic porphyritic dike. The second interval is composed of up to 3% pyrite-silica flooding, 1% chalcopyrite and quartz veins within a strong silica and sericite altered felsic porphyritic dike. The third and fourth intervals are composed of up to 20% pyrite-silica flooding, up to 2% chalcopyrite, 1% quartz-tourmaline veins and local visible gold within strong silica and strong sericite altered felsic porphyritic dikes. The last interval is composed of 10% pyrite stringers, 2% disseminated pyrite and local visible gold within a strong sericite and strong silica altered felsic porphyritic dike.

OSK-W-18-1423 intersected 5.63 g/t Au over 2.2 metres in Caribou Extension. Mineralization is composed of 1% stringer and disseminated pyrite within a strong sericite altered andesite.

OSK-W-18-1430 intersected 7.91 g/t Au over 2.0 metres in FW1. Mineralization is composed of up to 30% semi-massive pyrite in stringers or pyrite-silica flooding and 5% disseminated pyrite within a moderate sericite altered felsic porphyritic dike.

OSK-W-18-1430-W1 intersected 4.95 g/t Au over 3.0 metres in FW2. Mineralization is composed of low core angle quartz-tourmaline veins with 2 % disseminated pyrite within a felsic porphyritic dike.

OSK-W-18-1431 intersected 5.73 g/t Au over 2.0 metres in FW4. Mineralization is composed of 2% pyrite stringers, 1% pyrite clusters within a strong sericite altered felsic porphyritic dike.

OSK-W-18-1431-W1 intersected two intervals: 3.06 g/t Au over 2.3 metres in FW1 and 13.5 g/t Au over 2.1 metres in FW3 FW. Both intersects are composed of up to 3% pyrite stringers, 2% disseminated pyrite and 1% pyrite clusters within strong sericite altered felsic porphyritic dikes.

OSK-W-18-1434 intersected two intervals: 11.6 g/t Au over 4.7 metres in FW3 and 16.0 g/t Au over 2.4 metres in FW3U. The first interval is composed of up to 15% pyrite stringers, pyrite-silica flooding, and local visible gold within a strong sericite and strong silica altered felsic porphyritic dike. The second interval is composed of 15% semi-massive pyrite, pyrite-tourmaline veins within a strong sericite altered felsic porphyritic dike.

OSK-W-18-1435 intersected two intervals in Caribou Extension: 34.3 g/t Au over 2.6 metres and 4.38 g/t Au over 2.0 metres. The first interval is composed of 80% massive pyrite veins and quartz-tourmaline veins within a strong chlorite, weak sericite and weak carbonate altered andesite. The second interval is composed of 15% pyrite stringers within a strong carbonate altered andesite.

OSK-W-18-1440 intersected 31.4 g/t Au over 2.7 metres in FW1. Mineralization is composed of up to 25% semi-massive pyrite, 5% pyrite-tourmaline veins, and local visible gold within a strong sericite and strong silica altered felsic porphyritic dike.

OSK-W-18-1441 intersected 8.06 g/t Au over 6.6 metres in Bobcat. Mineralization is composed of 7% disseminated pyrite and 3% pyrite-tourmaline stringers within a strong fuchsite and silica altered gabbro.

OSK-W-18-1445 intersected 5.75 g/t Au over 3.5 metres in Caribou Extension. Mineralization is composed of local visible gold and up to 35% pyrite in stringers, pyrite-tourmaline veins and clusters within a strong sericite and silica altered felsic porphyritic dike.

OSK-W-18-1446 intersected three intervals: 10.8 g/t Au over 3.2 metres in FW1, 4.27 g/t Au over 2.0 metres in FW2 and 4.05 g/t Au over 2.2 metres in FW3. The first interval is composed of up to 5% disseminated pyrite and pyrite-tourmaline veins and local visible gold within a strong silica and sericite altered felsic porphyritic dike. The second interval is composed of 3% disseminated pyrite in quartz-tourmaline veins within a moderate sericite altered felsic porphyritic dike. The last interval is composed of local visible gold, up to 5% pyrite stringers and pyrite-silica flooding within a strong silica altered felsic porphyritic dike.

OSK-W-18-1448 intersected 6.02 g/t Au over 2.0 metres in Caribou. Mineralization is composed of 9% pyrite stringers within a moderate silica and sericite altered felsic porphyritic dike.

OSK-W-18-1459 intersected 8.26 g/t Au over 2.0 metres in Bobcat. Mineralization is in a crustiform vein and composed of up to 3% disseminated pyrite within a strong silica and moderate fuchsite altered gabbro.

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 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; the type of drilling included in the drill program (definition drilling, expansion drilling to the NE of the main deposit and 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 68.5 g/t Au OVER 2.9 METRES AT LYNX

Infill Drilling Continues to Encounter High-Grade Gold

 (Toronto, April 17, 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 Township, 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 17 intercepts in 5 drill holes and 6 wedges focused on infill drilling in the Lynx deposit are presented below. Today’s infill drilling results will not be included in the pending mineral resource scheduled for release in May 2018.

Highlights from the new results include: 68.9 g/t Au over 2.9 metres in OSK-W-18-1443; 33.8 g/t Au over 5.0 metres and 48.0 g/t Au over 2.0 metres in OSK-W-18-1436; 80.0 g/t Au over 2.1 metres in OSK-W-18-1367-W2 and 28.0 g/t Au over 3.0 metres in OSK-W-17-1397. 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-17-1166-W4 672.0 674.0 2.0 11.1   Lynx 2 Lynx
OSK-W-17-1343-W2 937.0 939.0 2.0 3.59   Lynx 4 Lynx
  1134.0 1137.0 3.0 6.31   Lynx 6 Lynx
OSK-W-17-1396 707.0 709.5 2.5 5.80   Lynx 4 Lynx
OSK-W-17-1397 113.6 116.0 2.4 3.35   Lynx HW Lynx
including 114.7 115.1 0.4 16.8  
  128.6 131.6 3.0 28.0 21.2 Lynx 1 Lynx
including 128.6 128.9 0.3 98.7  
including 130.9 131.2 0.3 168 100
  173.0 175.0 2.0 5.38   Lynx 2 Lynx
including 173.0 174.0 1.0 10.7  
OSK-W-18-923-W2 895.0 897.2 2.2 5.32   Lynx 4 Lynx
including 895.8 896.1 0.3 38.5  
  911.1 917.0 5.9 10.1   Lynx 4 Lynx
including 916.2 917.0 0.8 60.8  
OSK-W-18-1169-W1 888.0 890.0 2.0 7.69   Lynx 4 Lynx
including 889.2 889.6 0.4 31.6  
OSK-W-18-1367-W2 1169.6 1171.7 2.1 80.0 22.8 Lynx 4 Lynx
including 1171.4 1171.7 0.3 501 100
OSK-W-18-1414-W2 1039.0 1041.0 2.0 5.38   Lynx 4 Lynx
including 1039.0 1039.9 0.9 11.6  
OSK-W-18-1429 688.4 690.5 2.1 16.9   Lynx HW Lynx
including 690.1 690.5 0.4 41.7  
OSK-W-18-1436 902.5 904.5 2.0 8.40   Lynx 4 Lynx
including 903.3 903.6 0.3 49.8  
  1062.3 1064.3 2.0 48.0 25.2 Lynx 4 Lynx
including 1063.8 1064.3 0.5 191  
  1069.2 1074.2 5.0 33.8   Lynx 4 Lynx
including 1069.2 1069.8 0.6 97.6  
OSK-W-18-1443 668.0 670.9 2.9 68.5 45.1 Lynx 4 Lynx
including 668.9 669.9 1.0 168 100

Notes:   True widths are estimated at 65 – 80% of the reported core length interval.  See “Quality Control” below.
Definitions: HW = Hanging Wall.

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Section
OSK-W-17-1166-W4 132 -59 1236 453621 5435639 4050
OSK-W-17-1343-W2 137 -56 1323 453570 5435490 3950
OSK-W-17-1396 134 -52 956 453439 5435484 3825
OSK-W-17-1397 333 -61 732 453300 5434964 3450
OSK-W-18-923-W2 137 -56 1164 453607 5435603 4025
OSK-W-18-1169-W1 129 -55 1301 453332 5435467 3725
OSK-W-18-1367-W2 131 -52 1224 453753 5435875 4300
OSK-W-18-1414-W2 133 -58 1095 453654 5435648 4100
OSK-W-18-1429 138 -49 820 453533 5435606 3975
OSK-W-18-1436 139 -52 1128 453372 5435509 3775
OSK-W-18-1443 136 -50 792 453440 5435478 3825

 

OSK-W-17-1166-W4 intersected 11.1 g/t Au over 2.0 metres in Lynx 2. Mineralization is composed of up to 5% interstitial and stringer pyrite within a moderately sericitized felsic fragmental intrusion.

OSK-W-17-1343-W2 intersected two intervals: 3.59 g/t Au over 2.0 metres in Lynx 4 and 6.31 g/t Au over 3.0 metres in Lynx 6. The first interval is composed of 1% pyrite stringers within a sericitized rhyolite. The second interval is composed of up to 1% disseminated and stringer pyrite and quartz-carbonate veins within a strong chlorite, weak sericite altered rhyolite.

OSK-W-17-1396 intersected 5.80 g/t Au over 2.5 metres in the Lynx 4. Mineralization is composed of up to 1% pyrite in quartz veins at a chlorite and fuchsite altered contact between a gabbro and rhyolite.

OSK-W-17-1397 intersected three intervals: 3.35 g/t Au over 2.4 metres in Lynx HW, 28.0 g/t Au over 3.0 metres in Lynx 1 and 5.38 g/t Au over 2.0 metres in Lynx 2. The first interval is composed of stringer and disseminated pyrite and quartz veins within a strong sericite altered rhyolite. The second interval is composed of up to 3% disseminated pyrite and pyrite-silica flooding within a strong silica altered rhyolite. The last interval is composed of up to 2% pyrite in fragments or disseminated within a strong sericite, strong carbonate altered felsic fragmental dike.

OSK-W-18-923-W2 intersected two intervals in Lynx 4: 5.32 g/t Au over 2.2 metres and 10.1 g/t Au over 5.9 metres. In the first interval, mineralization is composed of 20% pyrite in quartz-tourmaline veins and disseminated within a fuchsite altered gabbro. The second interval is composed of 5% disseminated pyrite and 5% pyrite-silica flooding within a strongly sericitized rhyolite.

OSK-W-18-1169-W1 intersected 7.69 g/t Au over 2.0 metres in Lynx 4. Mineralization is composed of up to 5% pyrite stringers and 1% quartz-tourmaline veins within a strong silica, moderate sericite altered rhyolite.

OSK-W-18-1367-W2 intersected 80.0 g/t Au over 2.1 metres in Lynx 4. Mineralization is composed of 5% pyrite stringers and 1% quartz-tourmaline veins within a moderate sericite and chlorite altered felsic porphyritic dike.

OSK-W-18-1414-W2 intersected 5.38 g/t Au over 2.0 metres in Lynx 4. Mineralization is composed of 10% disseminated pyrite and 1% ptygmatic tourmaline veins at the contact of moderate silica and fuchsite altered gabbro.

OSK-W-18-1429 intersected 16.9 g/t Au over 2.1 metres in Lynx HW. Mineralization is composed of 5% pyrite stringers and 5% disseminated pyrite and local visible gold within strong silica, strong sericite and weak fuchsite altered gabbro.

OSK-W-18-1436 intersected three intervals in Lynx 4: 8.40 g/t Au over 2.0 metres, 48.0 g/t Au over 2.0 metres and 33.8 g/t Au over 5.0 metres. The first interval is composed of up to 5% pyrite-silica flooding with local visible gold within a strong silica altered rhyolite. The second interval is composed of up to 10% pyrite stringers, 5% pyrite-silica flooding and local visible gold within a strong silica altered rhyolite. The last interval is composed of 10% pyrite-silica flooding and local visible gold within a strong silica altered rhyolite.

OSK-W-18-1443 intersected 68.5 g/t Au over 2.9 metres in Lynx 4. The mineralization is composed of 15% pyrite-silica flooding and 15% disseminated pyrite within a moderate silica, sericite, carbonate and fuchsite altered gabbro.

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 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; 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 40.8 g/t Au OVER 4.1 METRES AT WINDFALL

Underdog FW4 Zone Continues to Expand

(Toronto April 10, 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 Township, 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 14 drill holes and 6 wedges focused on infill and expansion drilling in the Main Windfall lake deposit are presented below.

Highlights from the new results include: 40.8 g/t Au over 4.1 metres in OSK-W-18-823-W2; 53.9 g/t Au over 2.9 metres in OSK-W-18-1402-W2; 36.1 g/t Au over 3.2 metres in OSK-W-18-1431 and 32.8 g/t Au over 2.3 metres in OSK-W-18-1435. 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-EAG-12-424 802.9 805.3 2.4 7.85 FW3 Underdog

including

804.7 805.3 0.6 28.5
  815.5 818.0 2.5 10.0 FW3 Underdog

including

816.0 817.0 1.0 20.9
OSK-W-16-706-W3 1027.0 1029.2 2.2 7.88   FW2 Underdog

including

1028.0 1028.7 0.7 20.3
OSK-W-17-943 610.8 616.0 5.2 3.25   Wolf HW Wolf
OSK-W-17-967 603.0 605.0 2.0 23.2 15.3 Caribou Ext. Caribou

including

603.5 603.8 0.3 153 100
  655.8 660.3 4.5 10.2   Caribou Ext. Caribou

including

658.1 658.5 0.4 45.8  
OSK-W-17-1139 953.8 956.0 2.2 4.44   FW3 Underdog
OSK-W-17-1308-W1 997.0 999.0 2.0 7.27   Wolf Wolf
OSK-W-17-1336-W1 1153.5 1161.0 7.5 6.12   FW3 Underdog

including

1157.0 1158.0 1.0 17.0  
OSK-W-17-1352 646.0 648.0 2.0 9.39   Caribou Ext. Caribou

including

646.8 647.5 0.7 26.4  
OSK-W-17-1368 236.0 238.0 2.0 3.77   Caribou Ext. Caribou
  270.9 273.0 2.1 8.05   Caribou Ext. Caribou

including

270.9 271.2 0.3 54.0
OSK-W-17-1369 212.0 218.3 6.3 5.67   Caribou Caribou
OSK-W-17-1371 565.0 567.0 2.0 3.19   Caribou Ext. Caribou

including

565.3 565.7 0.4 14.8
OSK-W-17-1378 695.0 697.0 2.0 4.03   Vein Zone 27

including

696.0 696.4 0.4 16.8
  720.2 722.5 2.3 9.26   Vein  

including

721.3 721.7 0.4 52.8
OSK-W-17-1402 1054.2 1059.2 5.0 5.38   FW3 Underdog
  1085.0 1087.0 2.0 4.09   FW3 Underdog
  1099.0 1101.0 2.0 4.99   FW3 Underdog
OSK-W-18-762-W1 1220.0 1222.0 2.0 11.1   FW4 Underdog

including

1221.0 1221.5 0.5 41.5
OSK-W-18-823-W2 843.7 846.0 2.3 11.7   FW1 Underdog

including

845.0 845.3 0.3 80.5
  858.4 862.5 4.1 40.8 29.3 FW1 Underdog

including

860.8 861.7 0.9 152 100
OSK-W-18-1402-W1 853.0 855.0 2.0 3.52   FW1 Underdog
  859.1 862.0 2.9 53.9   FW1 Underdog
  1088.9 1091.5 2.6 6.63   FW3 Underdog

including

1090.3 1090.8 0.5 26.9
  1150.6 1153.0 2.4 4.47   FW4 Underdog

including

1150.6 1151.1 0.5 12.8
OSK-W-18-1421 872.6 875.8 3.2 36.1   FW4 Underdog

including

874.5 875.5 1.0 81.8
OSK-W-18-1431 894.0 896.0 2.0 3.57   FW2 Underdog

including

894.8 895.2 0.4 17.6
  922.3 925.1 2.8 13.5   FW3 Underdog

including

923.2 924.3 1.1 32.1
OSK-W-18-1435 301.5 303.8 2.3 32.8 31.1 Bobcat Bobcat

including

302.1 302.8 0.7 106 100
OSK-W-18-1441 304.0 306.8 2.8 3.41   Bobcat Bobcat

Notes: True widths are estimated at 65 – 80% of the reported core length interval. See “Quality Control” below.
Definitions: HW = Hanging Wall, Ext = extension.

President and CEO John Burzynski commented: “Good results again from our drilling at Windfall as we look forward to our initial mineral resource estimate on schedule for delivery in May. Although today’s results are outside the cut-off date and won’t be included in the mineral resource calculation in mid-March, they will add to the upside potential of Windfall as we head towards the feasibility study in early 2019. Particularly encouraging is that we are still seeing expansion potential in all of the main zones at Windfall-Lynx underscored in today’s results with the extension of the Underdog FW4 Zone by 70 metres up plunge from the previous mineralized intercept.”

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Section
OSK-EAG-12-424 330 -55 1003 452598 5434580 2650
OSK-W-16-706-W3 327 -57 1061 452611 5434418 2575
OSK-W-17-943 331 -55 744 452660 5434495 2675
OSK-W-17-967 337 -62 720 453176 5434908 3300
OSK-W-17-1139 333 -56 1092 452473 5434470 2500
OSK-W-17-1308-W1 332 -53 1032 453209 5434467 3125
OSK-W-17-1336-W1 335 -61 1335 452616 5434449 2600
OSK-W-17-1352 327 -50 909 453379 5434741 3400
OSK-W-17-1368 330 -64 762 452953 5434874 3100
OSK-W-17-1369 330 -49 786 452435 5434680 2550
OSK-W-17-1371 334 -69 981 453100 5434875 3225
OSK-W-17-1378 331 -56 741 452688 5434638 2750
OSK-W-17-1402 330 -59 1122 452616 5434449 2600
OSK-W-18-762-W1 332 -56 1299 452730 5434409 2675
OSK-W-18-823-W2 330 -56 918 452565 5434414 2550
OSK-W-18-1402-W1 330 -59 1224 452616 5434449 2600
OSK-W-18-1421 340 -47 918 452216 5434360 2200
OSK-W-18-1431 337 -62 1128 452287 5434336 2250
OSK-W-18-1435 331 -65 801 453028 5434848 3150
OSK-W-18-1441 328 -60 441 452886 5434912 3075

OSK-EAG-12-424 intersected two intervals in FW3: 7.85 g/t Au over 2.4 metres and 10.0 g/t Au over 2.5 metres. The first interval is composed of up to 2% disseminated pyrite and 1% pyrite stringers at the contact between a chloritized andesite and a sericitized porphyritic dike. The second interval contains up to 2% pyrite and pyrite-tourmaline stringers within a strongly sericitized andesite with moderate fuchsite alteration.

OSK-W-16-706-W3 intersected FW2 returning 7.88 g/t Au over 2.2 metres in the Underdog Corridor. Mineralization is composed of 8% pyrite stringers within a moderately silicified and sericitized felsic porphyritic dike with weak fuchsite alteration.

OSK-W-17-943 new assay results extend the previously reported result of 4.51 g/t Au over 2.0 metres (March 2, 2018) to 3.25 g/t Au over 5.2 metres in Wolf HW. Mineralization is composed of 5% pyrite stringers, 2% disseminate pyrite within a sericitized and strongly silicified felsic porphyritic dike.

OSK-W-17-967 intersected two intervals in Caribou Extension: 23.2 g/t Au over 2.0 metres and 10.2 g/t Au over 4.5 metres. The first interval is composed of 2% pyrite stringers and disseminated pyrite within a strong sericite, weak silica altered rhyolite. The second interval is composed of 2% pyrite stringers, disseminated pyrite and quartz-tourmaline veins within a sericitized felsic porphyritic dike.

OSK-W-17-1139 intersected 4.44 g/t Au over 2.2 metres in FW3. Mineralization is composed of up to 2% pyrite stringers hosted in a sericitized felsic porphyritic dike.

OSK-W-17-1308-W1 intersected 7.27g/t Au over 2.0 metres in Wolf. Mineralization is composed of trace pyrite stringers and disseminated in moderately chloritized and sericitized felsic porphyritic dike.

OSK-W-17-1336-W1 intersected 6.12 g/t Au over 7.5 metres in FW3. Mineralization is composed of up to 5% pyrite clusters, 1% pyrite stringers and a 20 centimetres zone with 15% ptygmatic tourmaline veins hosted in a sericitized and silicified felsic porphyritic dike.

OSK-W-17-1352 intersected 9.39 g/t Au over 2.0 metres in Caribou Extension. Mineralization is composed of up to 8% tourmaline-pyrite stringers at the contact between a gabbro and a felsic intrusive unit with weak fuchsite alteration.

OSK-W-17-1368 intersected 3.77 g/t Au over 2.0 metres and 8.05 g/t Au over 2.1 metres in Caribou Extension. The first interval is composed of trace pyrite in stringers and disseminated within a weak sericite and silica altered felsic porphyritic dike. The second interval is composed of 2% pyrite stringers, 5% pyrite-tourmaline stringers, 3% ptygmatic tourmaline veins within a sericitized and silicified rhyolite.

OSK-W-17-1369 intersected 5.67 g/t Au over 6.3 metres in Caribou. Mineralization is composed of up to 7% pyrite stringers and 10% disseminated pyrite in an alternation of mafic and felsic volcanic units.

OSK-W-17-1371 intersected 3.19 g/t Au over 2.0 metres in Caribou Extension. Mineralization is composed of disseminated pyrite and pyrite in quartz-tourmaline veins within a sericitized rhyolite.

OSK-W-17-1378 intersected 4.03 g/t Au over 2.0 metres in Zone 27 and 9.26 g/t Au over 2.3 metres in a vein. The first interval is composed of 5% pyrite within a felsic porphyritic dike. The second interval is composed of quartz-carbonate vein with local visible gold hosted in the Red Dog intrusion.

OSK-W-17-1402 intersected 5.38 g/t Au over 5.0 metres, 4.09 g/t Au over 2.0 metres and 4.99 g/t Au over 2.0 metres in FW3. All three mineralized intervals are composed of up to 1% pyrite-silica flooding and trace pyrite stringers within a sericitized felsic porphyritic dike.

OSK-W-18-762-W1 intersected 11.1 g /t Au over 2.0 metres in FW4. Mineralization is composed of 2% pyrite stringers, 1% pyrite-tourmaline stringers and 30 centimetres of strong pyrite silica flooding within a sericitized and silicified felsic porphyritic dike.

OSK-W-18-823-W2 intersected two intervals in FW1: 11.7 g/t Au over 2.3 metre and 40.8 g/t Au over 4.1 metres. The first interval is composed of a pyrite-tourmaline stringer with 20% pyrite and local visible gold. Mineralization is in strong pervasive silica flooding and calcite alteration within a sericitized felsic porphyritic dike. The second interval is composed of up 2% pyrite stringers, trace pyrite-tourmaline stringer, disseminated pyrite, chalcopyrite and local visible gold within a moderate sericite altered, fragmental, felsic porphyritic dike.

OSK-W-18-1402-W1 intersected four intervals: 3.52 g/t Au over 2.0 metres and 53.9 g/t Au over 2.9 metres in FW1, 6.63 g/t Au over 2.6 metres in FW3 and 4.47 g/t Au over 2.4 metres in FW4. In the first and second intervals, mineralization is composed of local visible gold, up to 15% pyrite and tourmaline ptygmatic veins within a strongly sericitized and silicified felsic porphyritic dike. The third interval is composed local visible gold, 2% pyrite stringers, 1% pyrite stockwork and 2% pyrite-silica flooding. FW3 mineralisation is hosted in sericitized and silicified felsic porphyritic dike. The last interval is composed of 5% disseminated pyrite and 3% pyrite in smoky quartz veins within a porphyritic felsic dike with weak sericite alteration and moderate silica alteration.

OSK-W-18-1421 intersected 36.1 g/t Au over 3.2 metres in FW4. Mineralization is composed of local visible gold and up to 20% pyrite stringers with pervasive silica flooding in a felsic fragmental intrusion. The interval extends FW4 70 metres up plunge of OSK-W-16-735 (33.6 g/t Au over 4.2 metres, previously reported November 8, 2016).

OSK-W-18-1431 intersected two intervals: 3.57 g/t Au over 2.0 metres in FW2 and 13.5 g/t Au over 2.8 metres FW3. The first interval is composed of up to 8% semi-massive pyrite and 1% pyrite clusters within in a moderately silicified felsic porphyritic dike. The second interval is composed of up to 30% semi-massive pyrite within a sericite and silica altered felsic porphyritic dike.

OSK-W-18-1435 intersected 32.8 g/t Au over 2.3 metres in Bobcat. Mineralization is composed of 15% disseminated pyrite, ptygmatic tourmaline veins and pervasive silica flooding within a silicified and sericitized felsic porphyritic dike.

OSK-W-17-1441 intersected 3.41 g/t Au over 2.8 metres in Bobcat. Mineralization is composed of up to 10% semi-massive pyrite, 3% pyrite-tourmaline stingers within a strongly sericitized rhyolite.

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 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; the type of drilling included in the drill program (definition drilling, expansion drilling to the NE of the main deposit and 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 403 g/t Au OVER 2.7 METRES AT LYNX

(Toronto, April 5, 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 township, 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 16 intercepts in 5 drill holes and 5 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: 403 g/t Au over 2.7 metres in OSK-W-18-1412-W1; 151 g/t Au over 2.2 metres in OSK-W-18-1414-W2, 40.1 g/t Au over 2.0 metres in OSK-W-17-1363, and 36.3 g/t Au over 2.0 metres in OSK-W-18-1436. 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-17-1166-W3 661.0 664.8 3.8 6.38 Lynx Lynx
including 663.5 664.8 1.3 14.3
1341.0 1343.0 2.0 4.06 Lynx 6 Lynx
1385.0 1387.0 2.0 6.26 Lynx 6 Lynx
including 1386.0 1386.3 0.3 41.3
OSK-W-17-1193 1659.8 1662.0 2.2 5.66 Vein Lynx
including 1659.8 1660.6 0.8 15.5
1682.0 1684.0 2.0 11.0 Vein Lynx
including 1682.5 1683.1 0.6 33.6
OSK-W-17-1343-W1 560.8 563.9 3.1 3.32 Lynx HW Lynx
OSK-W-17-1363 222.0 224.0 2.0 3.28 Lynx HW Lynx
470.5 472.5 2.0 40.1 VNCR Lynx
including 470.5 471.5 1.0 79.9
OSK-W-17-1379 136.4 138.5 2.1 5.62 Lynx 1 Lynx
including 136.4 137.0 0.6 18.9
OSK-W-17-1413 534.6 537.0 2.4 5.77 Lynx 4 Lynx
742.0 744.0 2.0 3.83 Lynx 4 Lynx
OSK-W-18-923-W1 876.2 878.2 2.0 3.39 Lynx 4 Lynx
OSK-W-18-1412-W1 720.0 722.7 2.7 403 50.9 Lynx 1 Lynx
including 721.7 722.7 1.0 1050 100
731.0 733.0 2.0 10.4 Lynx 1 Lynx
including 731.9 733.0 1.1 17.9
OSK-W-18-1414-W2 934.5 936.7 2.2 151 83.5 Lynx 4 Lynx
including 934.5 935.0 0.5 369 100
including 935.8 936.7 0.9 117 100
OSK-W-18-1436 546.0 548.0 2.0 36.3 Lynx 2 Lynx
including 547.0 547.6 0.6 91.0

Notes: True widths are estimated at 65 – 80% of the reported core length interval. See “Quality Control” below.
Definitions: HW = Hanging Wall; VNCR = Crustiform Vein.

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Section
OSK-W-17-1166-W3 132 -59 1551 453621 5435639 4050
OSK-W-17-1193 141 -59 1803 453806 5435726 4275
OSK-W-17-1343-W1 137 -56 870 453570 5435490 3950
OSK-W-17-1363 341 -72 513 453458 5435025 3625
OSK-W-17-1379 332 -66 540 452781 5434772 2900
OSK-W-17-1413 137 -53 996 453153 5435214 3450
OSK-W-18-923-W1 137 -56 962 453607 5435603 4025
OSK-W-18-1412-W1 133 -51 825 453684 5435676 4125
OSK-W-18-1414-W2 133 -58 1095 453654 5435648 4100
OSK-W-18-1436 139 -52 1128 453372 5435509 3775

President and CEO John Burzynski commented: “We continue to see good results from our drilling at Lynx and are looking forward to our initial mineral resource estimate which is on schedule for delivery in May. The Lynx Corridor was discovered by the Osisko team just a year ago and has been traced out over a length of almost two kilometres and remains open along strike. As we closed the database for the mineral resource calculation in mid-March, today’s results will not be included but will add to the upside potential of the Lynx deposit as we head towards the feasibility study in early 2019.”

OSK-W-17-1166-W3 intersected three intervals: 6.38 g/t Au over 3.8 metres in Lynx Corridor, 4.06 g/t Au over 2.0 metres and 6.26 g/t Au over 2.0 metres in Lynx 6. The first interval is composed of 2% pyrite clusters and 1% pyrite stringers in a strongly sericitized felsic fragmental intrusion. The second interval is composed of 3% pyrite clusters and one pyrite stringers within a strongly sericitized rhyolite. The last interval is composed of pyrite stringers and pyrite-silica flooding within a weak sericite altered felsic porphyritic dike.

OSK-W-17-1193 intersected two intervals in a shear zone, 200 metres south of Lynx 6 returned 5.66 g/t Au over 2.2 metres and 11.0 g/t Au over 2.0 metres. In the first interval, mineralization is composed of 3% disseminated pyrrhotite and the second interval is composed of 2% pyrite clusters and pyrrhotite traces. Small quartz veins are with the mineralization and hosted in a sheared, strongly sericitized andesite.

OSK-W-17-1343-W1 intersected 3.32 g/t Au over 3.1 metres in Lynx HW. Mineralization is composed of trace pyrite within moderate sericite altered gabbro.

OSK-W-17-1363 intersected two intervals: 3.28 g/t Au over 2.0 metres in the Lynx HW and 40.1 g/t Au over 2.0 metres in a crustiform vein. In the first interval, mineralization is composed of disseminated pyrite and pyrite stringers within a chloritized rhyolite. The second interval is composed of 7% pyrite stringers and pyrite-silica flooding within a strong chlorite, strong fuchsite and weak silica altered gabbro. The interval is 85 metres down plunge of OSK-W-17-1121 (8.62 g/t over 2.7 metres previously reported Octobre 12, 2017).

OSK-W-17-1379 intersected 5.62 g/t Au over 2.1 metres in Lynx 1. Mineralization is composed of up to 5% pyrite stringers within a strong sericite, chlorite and fuchsite altered felsic porphyritic dike.

OSK-W-17-1413 intersected two intervals in Lynx 4: 5.77 g/t Au over 2.4 metres and 3.83 g/t Au over 2.0 metres. In the first interval, mineralization is composed of 1% disseminated pyrite and 1% pyrite-silica flooding within a strongly silicified, large quartz eyes, felsic porphyritic intrusion. The interval is 100 metres south-west of OSK-W-17-827 (3.63 g/t over 3.0 metres previously reported July 12, 2017). The second interval is composed of disseminated pyrite within a strong chlorite and weak fuchsite altered andesite.

OSK-W-18-923-W1 intersected 3.39 g/t Au over 2.0 metres in Lynx 4. Mineralization is composed of 2% pyrite clusters, 1% pyrite stringers and 1% disseminated pyrite in quartz vein fracture filling. Mineralization is at a sericite and fuchsite altered contact between a gabbro and a rhyolite.

OSK-W-18-1412-W1 intersected two intervals: 403 g/t Au over 2.7metres and 10.4 g/t Au over 2.0 metres in Lynx 1. The first interval is composed of up to 5% pyrite as stringers, clusters, and disseminated, 2% disseminated chalcopyrite and local visible gold within a moderate sericite, silica and fuchsite altered gabbro. The second interval is composed of up to 10% disseminated pyrite, up to 10% pyrite-tourmaline veins and 5% disseminated pyrite within a moderate silica, moderate sericite and weak fuchsite altered gabbro.

OSK-W-18-1414-W2 intersected 151 g/t Au over 2.2 metres in Lynx 4. Mineralization is composed of 1% pyrite-tourmaline veins, 1% pyrite clusters, up to 8% disseminated pyrite and local visible gold within a strong silica, sericite and fuchsite altered gabbro.

OSK-W-18-1436 intersected 36.3 g/t Au over 2.0 metres in Lynx 2. Mineralization is composed of up to 2% pyrite stringers and 2% ptygmatic quartz-tourmaline veins within strong silica and sericite altered gabbro.

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