58.9 g/t Au Over 14.7 Metres

(Toronto, March 29, 2022) Osisko Mining Inc. (OSK:TSX. “Osisko” or the “Corporation”) is pleased to provide new analytical results from the ongoing drill program at its 100% owned Windfall gold project located in the Abitibi greenstone belt, Urban Township, Eeyou Istchee James Bay, Québec.

Significant new analytical results presented below include 27 intercepts in 8 drill holes (1 from surface, 8 from underground) and 8 wedges. Infill intercepts are located inside defined January 2022 mineral resource estimate (“MRE”) blocks (see Osisko news release dated January 10, 2022). Expansion intercepts are located outside the January 2022 MRE blocks and either expand resource wireframes or are in a defined zone or corridor but do not yet correlate to a specific wireframe.

Osisko Chief Executive Officer John Burzynski commented: “The infill program at Windfall continues to intercept high-grade mineralization. Today’s wide headline hole comes from Triple Lynx wireframe 3161 which has another wide zone of 41.4 g/t Au over 9.0 metres. Infill at Underdog is also returning intercepts of over one ounce per tonne over more than two meters.”

Selected high-grade intercepts include: 58.9 g/t Au over 14.7 metres in WST-21-0996A; 41.4 g/t Au over 9.0 metres in WST-21-0928; 88.0 g/t Au over 3.0 metres in WST-21-0997; 49.8 g/t Au over 3.9 metres in WST-21-0914; 81.5 g/t Au over 2.0 metres in WST-21-0936A; and 60.0 g/t Au over 2.4 metres in OSK-W-21-2463-W3. Maps showing hole locations and full analytical results are available at www.osiskomining.com. Maps: Long Section_In EN 20220329, PR_EN_20220329_Surface, PR_EN_20220329_UG.

Infill Drilling

Hole No. From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t)         cut to 100 g/t Zone Corridor
OSK-W-21-1871-W3 816.3 820.7 4.4 22.6   UDD_4101 Underdog
including 816.3 817.0 0.7 86.0  
and 820.2 820.7 0.5 60.6  
OSK-W-21-2463-W3 971.5 973.9 2.4 60.0 47.1 UDD_4122 Underdog
including 972.8 973.9 1.1 128 100
OSK-W-21-2544-W1 791.7 794.0 2.3 4.13   TLX_3184 Triple Lynx
including 791.7 792.0 0.3 11.6  
  797.7 800.0 2.3 12.2   TLX_3159 Lynx HW
including 798.3 798.9 0.6 45.3  
OSK-W-21-2599 702.8 705.8 3.0 4.83   CA2_2208 Caribou
including 702.8 703.5 0.7 16.6  
WST-21-0914 250.1 254.0 3.9 49.8 46.3 LSW_3500 Lynx SW
including 250.1 250.4 0.3 146 100
WST-21-0928 273.1 282.1 9.0 41.4 33.0 TLX_3161 Triple Lynx
including 275.8 277.1 1.3 155 96.5
WST-21-0936A 527.0 529.0 2.0 81.5 25.2 LX4_3450 Lynx 4
including 527.8 528.3 0.5 325 100
WST-21-0996A 146.3 161.0 14.7 58.9 32.2 TLX_3161 Triple Lynx
including 150.6 151.3 0.7 650 100
WST-21-0997 589.0 592.0 3.0 88.0 43.0 LX4_3430 Lynx 4
including 589.7 590.7 1.0 235 100
WST-22-1000 166.0 168.1 2.1 5.82   TLX_3163 Triple Lynx
including 167.2 167.7 0.5 22.1  
  232.8 235.0 2.2 5.09   TLX_3169 Triple Lynx
  256.4 258.6 2.2 4.43   TLX_3175 Triple Lynx
including 256.4 256.9 0.5 18.1  
  372.3 374.5 2.2 4.03   TLX_3191 Triple Lynx
including 373.7 374.5 0.8 9.19  
WST-22-1001 503.4 506.3 2.9 6.60   LX4_3404 Lynx 4
including 505.5 505.8 0.3 19.5  
WST-22-1006 186.8 189.0 2.2 35.6 14.8 TLX_3121 Triple Lynx
including 186.8 187.1 0.3 252 100
  512.0 518.3 6.3 9.22   LX4_3404 Lynx 4
including 512.3 513.5 1.2 25.7  
and 517.8 518.3 0.5 39.4  

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See “Quality Control and Reporting Protocols” below. CA2= Caribou 2, LX4 = Lynx 4, LSW = Lynx Southwest, TLX = Triple Lynx and UDD=Underdog.


Expansion Drilling

Hole No. From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t)         cut to 100 g/t Zone Corridor
OSK-W-21-2540-W3 1280.0 1282.0 2.0 17.7   LX4 Lynx 4
including 1281.4 1282.0 0.6 58.6  
OSK-W-21-2540-W9 1192.0 1194.0 2.0 3.68   LX4 Lynx 4
  1202.0 1208.0 6.0 7.68   LX4 Lynx 4
including 1207.0 1208.0 1.0 32.9  
  1230.0 1232.0 2.0 15.3   LX4 Lynx 4
  1282.7 1287.8 5.1 4.94   LX4 Lynx 4
including 1287.0 1287.8 0.8 19.3  
OSK-W-21-2646-W1 1067.0 1070.0 3.0 3.95   TLX Triple Lynx
OSK-W-22-2540-W12 867.4 869.5 2.1 6.29   LNX Lynx
including 868.4 868.7 0.3 39.5  
OSK-W-22-2540-W13 879.5 881.8 2.3 7.40   LNX Lynx
including 879.5 880.4 0.9 18.8  
  940.0 942.0 2.0 6.01   TLX Triple Lynx
including 940.0 940.5 0.5 23.3  
WST-22-1006 609.0 611.1 2.1 8.40   LX4 Lynx 4
including 609.9 610.6 0.7 24.8  

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See “Quality Control and Reporting Protocols” below., LNX = Lynx, LX4 = Lynx 4 and TLX = Triple Lynx.


Drill hole location

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Elevation Section
OSK-W-21-1871-W3 331 -56 906 452496 5434397 402 2475
OSK-W-21-2463-W3 339 -65 1299 452617 5434447 402 2600
OSK-W-21-2540-W3 117 -60 1470 453465 5435640 410 3925
OSK-W-21-2540-W9 117 -60 1349 453465 5435640 410 3925
OSK-W-21-2544-W1 128 -50 1140 452960 5435539 419 3425
OSK-W-21-2599 328 -62 774 452787 5434526 397 2800
OSK-W-21-2646-W1 109 -58 1236 453326 5435648 413 3800
OSK-W-22-2540-W12 117 -60 885 453465 5435640 410 3925
OSK-W-22-2540-W13 117 -60 911 453465 5435640 410 3925
WST-21-0914 148 -59 502 453105 5435066 231 3325
WST-21-0928 154 -70 391 453507 5435327 -7 3800
WST-21-0936A 137 -48 570 453257 5435209 96 3525
WST-21-0996A 143 -45 427 453358 5435297 -149 3675
WST-21-0997 119 -45 640 453506 5435326 -90 3800
WST-22-1000 139 -45 447 453359 5435297 -149 3675
WST-22-1001 124 -46 637 453506 5435326 -90 3800
WST-22-1006 122 -45 610 453506 5435326 -90 3800


Caribou Zone

Mineralization most commonly occurs in gold-bearing pyrite stockworks as well as semi-massive pyrite replacement zones associated with phyllic alteration (sericite-pyrite ± silica) with sulphides, pyrite dominated with minor chalcopyrite and sphalerite ranging from trace to up to 20%, and local visible gold. Mineralization is hosted in rhyolites or mafic-intermediate volcanics frequently at or near faults or the contact with felsic porphyritic intrusions.


Lynx Zone

Mineralization occurs as grey to translucent quartz-carbonate-pyrite-tourmaline veins and pyrite replacement zones and stockworks. Vein-type mineralization is associated with haloes of pervasive sericite-pyrite ± silica alteration and contain sulphides (predominantly pyrite with minor amounts of chalcopyrite, sphalerite, galena, arsenopyrite, and pyrrhotite) and local visible gold. Replacement mineralization is associated with strong pervasive silica-sericite-ankerite ± tourmaline alteration and contains disseminated pyrite from trace to 80% with local visible gold. Pyrite stockworks can form envelopes that reach several tens of metres in thickness. Fuchsite alteration is common and is spatially constrained to near the gabbros. Mineralization occurs at or near geological contacts between felsic porphyritic or fragmental intrusions and the host rhyolites or gabbros and locally can be hosted along the gabbro-rhyolite contact.



Mineralization most commonly occurs in gold-bearing quartz-pyrite (± tourmaline) veins and as disseminated, stringer, semi-massive to massive pyrite with minor sphalerite, chalcopyrite and molybdenite associated with strong sericite and silica alteration. Mineralization is hosted along the intrusive contacts of a three-phase composite felsic porphyritic unit which cross-cuts felsic and mafic volcanic sequences.


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), Director of Exploration for Osisko’s Windfall 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 width determination is estimated at 55-80% of the reported core length interval for the zone. 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 3.5 g/t Au diluted over core lengths of at least 2.0 metres. NQ core assays were obtained by either 1-kilogram screen fire assay or standard 50-gram fire-assaying-AA finish or gravimetric finish at (i) ALS Laboratories in Val d’Or, Québec, Vancouver, British Colombia, Lima, Peru or Vientiane, Laos (ii) 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 a Four Acid Digestion-ICP-MS 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 Gold Deposit

The Windfall gold deposit is located between Val-d’Or and Chibougamau in the Abitibi region of Québec, Canada. The Mineral Resource Estimate (“MRE“) defined by Osisko, as disclosed in the news release dated January 10, 2022 is supported by the technical report entitled “Mineral Resource Estimate Update for the Windfall Project” dated February 10, 2022 (with an effective date  of October 21, 2021), and assuming a cut-off grade of 3.50 g/t Au, comprises 565,000 tonnes at 11.6 g/t Au (210,000 ounces) in the measured mineral resource category, 8,907,000 tonnes at 10.5 g/t Au (2,994,000 ounces) in the indicated mineral resource category and 13,035,000 tonnes at 8.6 g/t Au (3,585,000 ounces) in the inferred mineral resource category. The key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in the January 10, 2022, news release, certain of which are described in the January 10, 2022, news release, are further described in the full technical report for this updated mineral resource estimate in accordance with NI 43-101 and is available on SEDAR (www.sedar.com) under the Corporation’s issuer profile. The Windfall gold deposit is currently one of the highest-grade resource-stage gold projects in Canada and has world-class scale. Mineralization occurs in three principal zones: Lynx, Main Zone, and Underdog. Mineralization is generally comprised of sub-vertical zones following intrusive porphyry contacts plunging to the northeast. The resources are defined from surface to a depth of 1,600 metres as it now includes the Triple 8 (T8) zone. The resources excluding T8 are defined from surface to a depth of 1,200 metres. The deposit remains open along strike and at depth. Mineralization has been identified at surface in some areas and as deep as 2,625 metres in others with significant potential to extend mineralization down-plunge and at depth.


About Osisko Mining Inc.

Osisko is a mineral exploration company focused on the acquisition, exploration, and development of gold resource properties in Canada. Osisko holds a 100% interest in the high-grade Windfall 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 Quévillon area (over 2,500 square kilometres).


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. Any statement that involves 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”, “potential”, “feasibility”, “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 news release contains the forward-looking information pertaining to, among other things: the Windfall gold deposit being one of the highest-grade resource-stage gold projects in Canada and having world-class scale; the key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in this news release; the prospects, if any, of the Windfall gold deposit; timing and ability of Osisko to file a technical report for the mineral resource estimate disclosed in this news release; the timing and ability of Osisko, if at all, to publish a feasibility study for the Windfall gold deposit; the amount and type of drilling to be completed and the timing to complete such drilling; the focus of the remaining infill drilling; the trend of grade increase; the Lynx zone remaining open to expansion down plunge; upgrading a inferred mineral resource to a measured mineral resource or indicated mineral resource category; future drilling at the Windfall gold deposit; the significance of historic exploration activities and results. 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 (infill) drilling; property and royalty interests in the Windfall gold deposit; the ability of the Corporation to obtain required approvals; 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.



John Burzynski
Chief Executive Officer
Telephone (416) 363-8653