Osisko Windfall Drilling Intercepts More High-Grade

Including 120 g/t Au Over 6.2 Metres


TORONTO, April 13, 2022 (GLOBE NEWSWIRE) -- 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 31 intercepts in 12 underground drill holes and 5 wedges. The infill intercepts are located inside defined January 2022 mineral resource estimate (“MRE”) blocks (see Osisko news release dated January 10, 2022). The 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: “We remain very pleased with the results of our infill and expansion drill program at Lynx. High grade zones continue to be intersected where expected and the expansion drilling continues to define additional zones nearby.”

Selected high-grade intercepts include: 120 g/t Au over 6.2 metres in OSK-W-21-2287-W14; 67.1 g/t Au over 4.4 metres in OSK-W-22-2646-W3; 111 g/t Au over 2.5 metres in WST-22-1009A; 82.6 g/t Au over 2.2 metres in WST-21-0997; 76.0 g/t Au over 2.3 metres in WST-21-0974; 63.9 g/t Au over 2.1 metres in WST-22-0999 and 60.8 g/t Au over 2.2 metres in OSK-W-22-2540-W13. Maps showing hole locations and full analytical results are available at www.osiskomining.com. Maps: Long Section_Infill EN 20220413, Long Section_Expan EN 20220413, PR_EN_20220413_Surface, PR_EN_20220413_UG..

Infill Drilling

Hole No.From (m)To (m)Interval (m)Au (g/t) uncutAu (g/t) cut to 100 g/tZoneCorridor
OSK-W-21-2287-W141253.01259.26.212051.4LX4_3449
Lynx 4
including1256.71257.20.5768100
OSK-W-22-2646-W31057.61062.54.915.6 TLX_3158
Triple Lynx
including1058.31058.70.499.1 
WST-21-0839512.0514.02.05.16 LX4_3470
Lynx 4
including512.3512.70.421.9 
WST-21-097444.046.32.376.031.8TLX_3161
Triple Lynx
including45.245.90.7245100
WST-21-0979189.4194.85.415.612.9TLX_3154
Triple Lynx
including192.0192.50.5130100
 197.1199.22.119.3 TLX_3184
Triple Lynx
including197.4197.70.344.4 
WST-21-0980602.8605.02.250.331.9LX4_3448
Lynx 4

including602.8603.50.7158100
WST-21-0997191.1193.32.282.644.7TLX_3121
Triple Lynx
including191.7192.40.7219100
WST-22-0999227.0229.02.09.37 TLX_3131
Triple Lynx
including227.7228.50.823.4 
 351.0353.12.14.13 LX4_3405
Lynx 4
including352.7353.10.420.8 
 376.9379.02.163.938.8LX4_3410
Lynx 4
including377.2378.00.8166100
 390.5394.03.527.4 LX4_3440
Lynx 4
including393.0394.01.076.3 
WST-22-1000202.3212.09.73.83 TLX_3145
Triple Lynx
including204.0205.21.211.7 
WST-22-1004320.5325.34.85.78 TLX_3131
Triple Lynx
including324.5324.80.318.1 
 504.0506.02.044.725.4LX4_3402
Lynx 4
including505.5506.00.5177100
WST-22-1005149.2157.68.44.96 TLX_3161Triple Lynx
WST-22-1006566.7569.12.415.1 LX4_3430
Lynx 4
including566.7567.00.389.3 
WST-22-1008147.8150.02.28.76 TLX_3161Triple Lynx
 210.0212.12.111.0 TLX_3169Triple Lynx
 217.7220.02.33.98 TLX_3175Triple Lynx
 226.0228.02.05.42 TLX_3175Triple Lynx
WST-22-1009A172.0174.02.08.64 LXM_3388
Lynx
including172.8173.30.522.9 
 485.5488.02.511160.3LX4_3404
Lynx 4
including485.5486.10.6240100
 499.0501.12.111.7 LX4_3430
Lynx 4
including499.9500.60.732.8 
 511.0513.02.03.52 LX4_3454
Lynx 4
including511.9512.30.414.9 

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

Expansion Drilling

Hole No.From (m)To (m)Interval (m)Au (g/t) uncutAu (g/t) cut to 100 g/tZoneCorridor
OSK-W-21-2381-W31204.21210.76.54.41 TLX_3172
Triple Lynx
including1209.71210.71.015.6 
OSK-W-21-2646-W11046.01055.49.411.6 TLX_3158
Triple Lynx
including1048.41048.70.365.8 
and1054.51055.40.954.7 
OSK-W-22-2540-W13987.8990.02.260.824.2TLX_3158
Triple Lynx
including988.1988.60.5261100
OSK-W-22-2646-W31181.71186.14.467.131.7TLX_3172
Triple Lynx
including1184.91186.11.2230100
WST-22-1008249.0251.52.55.05 TLXTriple Lynx
WST-22-1009A576.1578.32.23.54 LX4
Lynx 4
including577.5578.30.89.57 

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

Drill hole location

Hole No.Azimuth (°)Dip (°)Length (m)UTM EUTM NElevationSection
OSK-W-21-2287-W14116-53133845360754357144044075
OSK-W-21-2381-W3134-53139245362054357904024125
OSK-W-21-2646-W1109-58123645332654356484143800
OSK-W-22-2540-W13117-60122045346654356394103925
OSK-W-22-2646-W3109-58125145332654356484143800
WST-21-0839140-385774533215435235553600
WST-21-0974142-11674534415435223-1573700
WST-21-0979178-552554533585435296-1493675
WST-21-0980131-386814533745435297-263675
WST-21-0997119-456404535065435326-903800
WST-22-0999134-264544534455435276-993725
WST-22-1000139-454474533605435297-1483675
WST-22-1004137-406004533225435236543600
WST-22-1005145-443344533605435297-1483675
WST-22-1006121-456164535065435326-903800
WST-22-1008148-424204533605435297-1483675
WST-22-1009A120-406034535075435332-473800

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.

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.

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