Osisko Announces New Results from Ongoing Drill Program at Windfall Lake Gold Project

Osisko Mining Inc. is pleased to announce new results from the ongoing drill program at its 100% owned Windfall Lake gold project located in Urban Township, Québec. The current drill program is being expanded to 150,000 metres, and combines definition drilling above the Red Dog intrusion ("Red Dog"), expansion drilling above and below Red Dog and exploration drilling on the greater deposit and overall property area. Six drills are currently on site, and an additional four drills will be added to the program in the coming months. A total of 5 new drill holes are reported in this release, and are presented in greater detail in the table below.

Significant new results include:  391 g/t Au over 3.1 metres (uncut) in DDH OSK-W-16-728 (14.7 g/t Au over 3.1 metres cut);  15.9 g/t Au over 8.9 metres in DDH OSK-W-16-706-W1; 10.6 g/t Au over 10.9 metres in DDH OSK-W-16-706-W1; and 5.75 g/t Au over 16.5 metres in DDH OSK-W-16-706-W1.

The new results demonstrate the high potential for significant new mineralization near the known Windfall mineral inventory through continued definition and exploratory drilling, specifically in the eastern extension of the deposit and below the Red Dog intrusion.

The main mineralized zones are hosted within three broad corridors of mineralization trending WSW - ENE. Moving south to north across the Windfall deposit these three corridors are:

• the Caribou Corridor (includes the Caribou Zone, Wolf Zone and the new "Wolf 2" Zone);
• the Zone 27 Corridor; and
• the "Underdog" Corridor (newly renamed, previously known as the FW series corridor) hosting all zones below the Red Dog dike and includes the newly reported "FW0" Zone; FW1 Zone; FW2 Zone; FW3 Zone; and FW4 Zone).

The primary corridors of mineralization are depicted in diagrams available on Osisko's website at www.osiskomining.com.

Highlights of Current Results

• Caribou Zone mineralized corridor has been extended by 230 metres farther than previously known to the ENE;  the partial results from hole DDH OSK-W-16-728 indicate the main deposit continues to host strong mineralization with a new high-grade intercept in Caribou Corridor; results for Zone 27 Corridor and Underdog Corridor are pending
• FW3 Zone expanded 50 metres down dip; new "FW0 Zone" defined in Underdog Corridor; new "Wolf 2 Zone" defined in Caribou Corridor
• Drill program expanded to 150,000 metres, current 6 drill rigs increasing to 10;  aggressive 200 metre, 400 metre and 600 metre step out drilling from eastern limit of known mineralization is planned to pursue the main deposit to the ENE

Details of significant new results are outlined in the table below:

Notes:
(1) For complete drilling results please see www.osiskomining.com.
(2) True widths are estimated at 65-80% of the reported core length interval. See "Quality Control" below.
(3) High grade values cut to 100 g/t Au

Drill Hole Collar Coordinates and Information:

President and Chief Executive Officer John Burzynski noted:  "In recent weeks, our corporate and exploration focus has turned solidly to the Windfall project. Results coming from the current drill program have centered our attention on the growing potential for Windfall to be our "company maker" deposit. We are increasing the scale of our drill program for the second time in the past 3 months, and are planning on adding another four drills and 50,000 metres of drilling. The exploration team is having increasing success at intersecting new extensions of the currently known zones, and have also successfully begun to define new parallel mineralized zones like the recently announced Wolf Zone within the primary mineralized corridors. All indications at this point are leading us to believe that we will continue to expand the main deposit as we advance drilling, particularly to the ENE and at depth. The results outlined in today's press release define significant extensions and additions to the main mineralization at Windfall, and have added a new emphasis on exploring the main deposit to follow the currently known mineralized corridors in the ENE direction to try to find the center of gravity of the deposit."

DDH OSK-W-16-309-W2 intersected 5.58 g/t Au over 3.0 meters, 60 metres to the northwest of FW3. This new intercept correlates with 4.3 g/t Au over 2.1 metres in previously reported hole EAG-13-320-W1 located 60 metres below.

DDH OSK-W-16-706-W1 confirmed a new zone ("FW0 Zone") located 50 metres to the SE of FW1 with an intercept of 28.1 g/t Au over 2.5 metres in an altered porphyry dyke with 1% pyrite stringers. The FW0 Zone is currently modelled for over 300 metres along strike and 100 metres vertical, and remains open along strike and at depth. The previously reported intercepts interpreted to be part of the FW0 Zone include 11.2 g/t Au over 3.4 metres in DDH OBM-16-614, 7.49 g/t Au over 7.0 metres in DDH OBM-15-564, and 12.5 g/t Au over 2.0 metres in OBM-15-560.

Three additional zones currently interpreted to represent elements of the FW2 Zone were intersected between FW1 and FW3, respectively returning: 10.6 g/t Au over 10.9 metres (hosted in a strongly silicified porphyry dyke containing 2-5% pyrite stringers with traces of sphalerite and specks of visible gold);  7.1 g/t Au over 5.0 metres and 18.6 g/t Au over 2.3 metres (both hosted in a porphyry dyke containing 2-3% pyrite stringers and traces of chalcopyrite).

This hole also expanded the FW3 Zone by 50 metres down dip, returning 15.9 g/t Au over 8.9 metres hosted in a porphyry dyke containing 2-3% pyrite stringers with traces of chalcopyrite and several specks of visible gold.

Additionally, the hole intersected gold mineralization below FW3 (currently interpreted as FW4 Zone), returning 8.74 g/t Au over 3.9 metres.

DDH OSK-W-16-718 extended the newly discovered Wolf Zone by 26 metres vertically with an intercept of 4.78 g/t Au over 2.6 metres located above previously reported DDH OBM-15-559 which returned 7.0 g/t Au over 10.0 metres. This drill hole also confirmed a new zone ("Wolf 2 Zone") located between the Caribou S-3 Zone and the recently discovered Wolf Zone with 8.5 g/t Au over 4.7 metres. Wolf 2 Zone extends for more than 130 metres laterally and is open in its up-dip extension;  it now includes previously reported intercepts of 9.09 g/t Au over 5.2 metres in DDH EAG-12-448, 3.25 g/t Au over 2.4 metres in DDH OSK-16-708-W1, and 3.33 g/t Au over 1.2 metres in DDH EAG-13-504.

DDH OSK-W-16-722 intersected new near surface gold mineralization returning 6.08 g/t Au over 2.1 metres at the contact of a porphyry dyke. This intersection correlates with a previously reported intersection of 5.23 g/t Au over 2.0 metres in DDH EAG-13-497 located 63 metres below and to the SW.

DDH OSK-W-16-728 intersected 391.43 g/t Au over 3.1 metres, (14.65 g/t Au over 3.1 metres cut to 100 g/t Au), including 3,020 g/t Au over 0.4 metres along the projected Caribou Zone. This drill hole is a 440 metre step-out to the ENE of the current mineral resource and is located 230 metres from the nearest known mineralization in previously reported DDH OBM-16-580 which returned 4.3 g/t Au over 5.4 metres.