Osisko Intersects 312 Metres Averaging 0.56% Cu at Gaspé

MONTREAL, Aug. 20, 2026 (GLOBE NEWSWIRE) -- Osisko Metals Incorporated (the “Company” or “Osisko Metals”) (TSX: OM; OTCQX: OMZNF; FRANKFURT: 0B51) is pleased to announce new results from the 2026 drill program at the Gaspé Copper Project, located in the Gaspé Peninsula of Eastern Québec.

New analytical results from the 2026 drill program are presented below (see Table 1), including 35 mineralized intercepts from 15 new drill holes. Reported “infill” intercepts are located within the 2026 MRE model (see April 14, 2026 news release) and will be focused on upgrading Inferred Mineral Resources to Measured or Indicated categories, as applicable. “Expansion” intercepts are located outside the 2026 MRE model and comprise either A) in-pit expansion, which offers potential to convert in-pit waste into additional resources within the 2026 MRE Whittle pit, or B) out-of-pit expansion, consisting of mineralization located out of the 2026 MRE Whittle pit, which may potentially lead to the definition of new resources. Some of the reported intercepts may have contiguous shallower infill as well as deeper expansion (noted as “Both”). Maps showing hole locations are available at www.osiskometals.com.

Osisko Metals Chief Executive Officer Robert Wares commented: “This new round of drilling continues to expand the known deposit, improve grade to the south, and convert waste rock to the southwest within the 2026 MRE Whittle pit volume to mineralized material. Drill holes 30-1218 and 30-1223 in particular added higher-grade material within and below the current pit volume. We are also seeing good intercepts of mineralization outside the 2026 MRE resource model and pit limits, particularly in hole 30-1215, which is located on the eastern margin of the Needle Mountain pit.”

Highlights

• 312.5 metres averaging 0.56% Cu (Infill) in DDH 30-1223
• 117.9 metres averaging 0.49% Cu (In-pit expansion) in DDH 30-1218
• 57.0 metres averaging 0.63% Cu (Out-of-pit expansion) in DDH 30-1213
• 79.0 metres averaging 0.43% Cu (Out-of-pit expansion) in DDH 30-1215
• 82.3 metres averaging 0.31% Cu (Infill) and 86.0 metres averaging 0.27% Cu (Infill) in DDH 30-1220
• 78.0 metres averaging 0.28% Cu (Out-of-pit expansion) in DDH 30-1209
  

Table 1: Infill and Expansion Drilling Results

DDH No.	From (m)	To (m)	Length (m)	Cu %	Ag g/t	Mo %	CuEq* %	Type**
30-1209	94.5	111.0	16.5	0.16	1.31	<0.005	0.16	Expansion 2
And	151.5	229.5	78.0	0.28	2.10	<0.005	0.28	Expansion 2
And	267.0	304.5	37.5	0.21	1.83	<0.005	0.21	Expansion 2
30-1210	250.0	316.3	66.3	0.31	3.71	0.012	0.35	Expansion 1
And	478.4	592.5	114.1	0.16	1.86	0.038	0.29	Expansion 2
30-1211	132.0	255.5	123.5	0.22	1.79	<0.005	0.22	Expansion 2
And	283.1	294.0	10.9	0.48	3.20	<0.005	0.49	Expansion 2
30-1212	116.5	145.5	29.0	0.26	2.84	<0.005	0.27	Expansion 1
And	188.3	206.9	18.6	0.31	3.28	<0.005	0.31	Expansion 1
30-1213	104.0	163.5	59.5	0.26	2.28	<0.005	0.26	Expansion 1
And	208.2	232.5	24.3	0.34	3.75	<0.005	0.35	Expansion 1
And	321.0	378.0	57.0	0.63	5.37	<0.005	0.64	Expansion 2
(including)	322.3	328.5	6.20	3.18	23.4	<0.005	3.20	Expansion 2
30-1214	216.8	224.0	7.2	1.33	5.97	<0.005	1.34	Expansion 2
And	296.0	342.0	46.0	0.28	1.74	<0.005	0.29	Expansion 2
30-1215	34.0	113.0	79.0	0.43	2.76	<0.005	0.43	Expansion 2
And	142.5	177.0	34.5	0.25	1.47	<0.005	0.25	Expansion 2
And	249.4	291.0	41.6	0.29	1.64	<0.005	0.29	Expansion 2
30-1216	94.5	119.5	25.0	0.25	1.81	<0.005	0.25	Expansion 1
And	234.0	279.0	45.0	0.26	1.67	<0.005	0.26	Expansion 2
30-1217	117.0	151.5	34.5	0.29	2.06	<0.005	0.29	Expansion 1
And	197.5	223.5	26.0	0.25	2.25	<0.005	0.25	Infill
And	300.0	337.5	37.5	0.26	2.93	<0.005	0.26	Infill
30-1218	84.6	202.5	117.9	0.49	4.95	<0.005	0.50	Expansion 1
(including)	165.0	174.0	9.0	2.73	26.8	<0.005	2.75	Expansion 1
And	225.0	247.3	22.3	0.37	3.07	<0.005	0.38	Expansion 2
And	279.7	309.0	29.3	0.34	5.03	<0.005	0.35	Expansion 2
30-1219	235.0	268.5	33.5	0.26	2.93	<0.005	0.27	Expansion 2
30-1220	83.0	165.3	82.3	0.31	2.17	<0.005	0.31	Infill
And	210.0	296.0	86.0	0.27	1.82	0.023	0.35	Infill
And	429.0	472.5	43.5	0.51	5.06	0.101	0.86	Infill
30-1221	46.0	64.5	18.5	0.39	2.23	<0.005	0.39	Expansion 2
And	213.3	256.5	43.2	0.22	1.31	<0.005	0.22	Expansion 2
30-1222	136.5	147.0	10.5	0.43	4.59	<0.005	0.43	Expansion 1
And	187.5	246.0	58.5	0.32	5.70	<0.005	0.33	Expansion 1
And	273.0	292.5	19.5	0.20	1.85	<0.005	0.20	Expansion 1
30-1223	28.0	340.5	312.5	0.56	4.89	<0.005	0.57	Infill
(including)	145.0	181.0	36.0	1.88	13.3	<0.005	1.90	Infill
(including)	253.5	264.0	10.5	2.66	23.5	<0.005	2.68	Infill

* See explanatory notes below on copper equivalent values and Quality Assurance/Quality Controls.
** Infill refers to intercepts within the current MRE model; Expansion 1 refers to in-pit intercepts outside of the current MRE model; Expansion 2 refers to out-of-pit intercepts outside of the MRE model. “Both” indicates drill holes that have contiguous shallower infill as well as deeper expansion intercepts.

Discussion

Drill hole 30-1209, located on the western flank of Needle East and 305 metres south of the 2026 MRE model, is a westerly dipping hole that constitutes the most southerly hole drilled to date. It cut three mineralized intervals, all out-of-pit expansion, the longest consisting of 78.0 metres averaging 0.28% Cu and 2.10 g/t Ag, extending mineralization in this area to a vertical depth of 300 metres.

Drill hole 30-1210, located just outside the western limit of the 2026 MRE model, is a westerly dipping hole that cut two mineralized intervals, including 66.3 metres averaging 0.31% Cu and 3.71 g/t Ag (in-pit expansion), followed by a deeper interval of 114.1 metres averaging 0.16% Cu and 1.86 g/t Ag (out-of-pit expansion), extending mineralization in this area to a vertical depth of 570 metres.

Drill hole 30-1211, located on the eastern margin of the Needle Mountain pit, is an easterly dipping hole that cut two mineralized intervals (out-of-pit expansion) where no mineralization was expected. The longest interval averaged 0.22% Cu and 1.79 g/t Ag over 123.5 metres, extending mineralization in this area to a vertical depth of 285 metres.

Drill hole 30-1212, located on the southwestern margin of the 2026 MRE model, is a westerly dipping hole that cut two narrow mineralized intervals (in-pit expansion), immediately above and within the C Zone skarn, averaging 0.26% to 0.31% Cu. The bulk of the C Zone horizon in this area comprises unmineralized marble.

Drill holes 30-1213 and 30-1217, located at the southern margin of the 2026 MRE model on the northern flank of Needle East Mountain, are two westerly dipping holes that were drilled to test under historical underground workings in the B Zone. Both holes hit three narrow zones of mineralization, 24 to 59 metres thick, with average grades ranging from 0.25% to 0.34% Cu, with 30-1213 also intersecting 57.0 metres averaging 0.63% Cu and 5.37 g/t Ag (out-of-pit expansion; including 6.2 metres averaging 3.18% Cu and 23.4 g/t Ag at a level immediately below the C Zone horizon).

Drill hole 30-1214, located on the southeastern margin of the Needle Mountain pit, is a westerly dipping hole that cut two mineralized intervals, including 7.2 metres averaging 1.33% Cu and 5.97 g/t Ag (within B Zone, out-of-pit expansion), followed by a deeper interval of 46.0 metres averaging 0.28% Cu and 1.74 g/t Ag (out-of-pit expansion), extending mineralization in this area to a vertical depth of 330 metres.

Drill holes 30-1215 and 30-1221, located on the eastern margin of the Needle Mountain pit, are westerly dipping holes that were drilled to test under the pit and historical underground workings in the B Zone. Both holes hit narrow zones of mineralization, 18 to 43 metres thick, with average grades ranging from 0.22% to 0.39% Cu (out-of-pit expansion), with 30-1215 also intersecting 79.0 metres averaging 0.43% Cu and 2.76 g/t Ag (out-of-pit expansion) at a level above the B Zone horizon.

Drill holes 30-1216 and 30-1219, located between Needle East and the Needle Mountain pit, are westerly dipping holes that were drilled to test an area with little historical drilling. Both holes hit narrow zones of mineralization, 25 to 45 metres thick, with average grades ranging from 0.25% to 0.26% Cu (out-of-pit expansion), at levels of the B and C Zone horizons.

Drill hole 30-1218, located between Needle East and the Needle Mountain pit approximately 120 metres from the SW limit of the 2026 MRE model, is an easterly dipping hole that was drilled to test under the historical underground workings in the B Zone. It cut three mineralized intervals, including 117.9 metres averaging 0.49% Cu and 4.95 g/t Ag (including 9.0 metres averaging 2.73% Cu and 26.8 g/t Ag), all within and above the B Zone (in-pit expansion), followed by two deeper intervals of 22.3 and 29.3 metres averaging 0.37% Cu and 0.34% Cu, respectively (out-of-pit expansion), extending mineralization in this area to a vertical depth of 300 metres.

Drill hole 30-1220 is an infill hole located near the western margin of the 2026 MRE model. It cut three mineralized intervals, including 82.3 metres averaging 0.31% Cu and 2.17 g/t Ag, followed by a deeper interval of 86.0 metres averaging 0.27% Cu, 0.023% Mo and 1.82 g/t Ag and a third interval of 43.5 metres averaging 0.51% Cu, 0.101% Mo and 5.06 g/t Ag. The presence in this hole, this far south of Copper Mountain, of higher-grade molybdenum mineralization is presently unexplained by the geological modelling.

Drill hole 30-1222, located between Needle East and the Needle Mountain pit approximately 75 metres from the SW limit of the 2026 MRE model, is an easterly dipping hole that was drilled to better define the boundary of the 2026 MRE model. It cut three narrow mineralized intervals (in-pit expansion), including 58.5 metres averaging 0.32% Cu and 5.70 g/t in and around the C Zone horizon, again allowing for potential expansion of the resource further southwest along the C Zone horizon.

Drill hole 30-1223 is a vertical infill hole located near the southern margin of the 2026 MRE model. It was drilled through a pillar of the B Zone underground workings and cut a thick mineralized interval from surface that returned 312.5 metres averaging 0.56% Cu and 4.89 g/t Ag, including two higher-grade intervals of 36.0 metres averaging 1.88% Cu and 13.3 g/t Ag at the level of the B Zone skarns, and 10.5 metres averaging 2.66% Cu and 23.5 g/t Ag at the level of the C Zone skarns. This hole extends mineralization in this area to a vertical depth of 340 metres.

Mineralization at Gaspé Copper is of porphyry copper/skarn type and occurs as disseminations and stockworks of chalcopyrite with pyrite or pyrrhotite and minor bornite and molybdenite. One prograde and at least five retrograde vein/stockwork mineralizing events have been recognized at Copper Mountain, which overprint earlier, stratiform, carbonate replacement skarn and porcellanite-hosted mineralization throughout the Gaspé Copper system. Porcellanite is a historical mining term used to describe bleached, pale green to white potassic-altered hornfels. Subvertical stockwork mineralization dominates at Copper Mountain whereas prograde bedding-parallel mineralization, which is mostly stratigraphically controlled, dominates in the area of lower Copper Mountain, Needle Mountain, Needle East, and Copper Brook. High molybdenum grades (up to 0.5% Mo) were locally obtained in both the C Zone and E Zone skarns away from Copper Mountain.

The 2022 to 2024 Osisko Metals drill programs were focused on defining open-pit resources within the Copper Mountain stockwork mineralization (see May 6, 2024 MRE press release). Extending the resource model south of Copper Mountain into the poorly-drilled prograde skarn/porcellanite portion of the system subsequently led to a significantly increased resource, mostly in the Inferred category (see November 14, 2024 MRE press release), and additional drilling in 2025 led to an additional significant increase in resources, mostly in the Measured and Indicated categories (see April 14, 2026 MRE press release).

The current drill program is designed to convert the bulk of the remaining 2026 MRE Inferred resources to Measured and Indicated categories, as well as test the expansion of the overall resource laterally to the south and southwest towards Needle East and Needle Mountain respectively.

Table 2: Drill hole locations

DDH No.	Azimuth (°)	Dip (°)	Length (m)	UTM E	UTM N	Elevation
30-1209	250	-75	360	316184	5424943	733
30-1210	250	-75	618	315995	5425836	560
30-1211	89	-76	321	315882	5425111	709
30-1212	250	-75	300	316189	5425395	586
30-1213	250	-82	486	316532	5425275	684
30-1214	250	-74	393	315891	5424984	764
30-1215	250	-45	366	315838	5425264	665
30-1216	250	-75	321	315893	5425422	638
30-1217	255	-76	426	316579	5425333	655
30-1218	75	-83	369	316116	5425199	690
30-1219	250	-70	300	316003	5425356	628
30-1220	224	-75	567	316151	5425776	563
30-1221	245	-70	309	315838	5425264	665
30-1222	70	-65	372	316086	5425341	607
30-1223	0	-90	453	316524	5425410	631

Explanatory note regarding copper-equivalent grades

Copper Equivalent (CuEq) grades are presented for illustrative purposes only to express the combined value of copper, molybdenum, and silver as a single copper grade. CuEq grades are calculated using long-term metal prices of US$4.50/lb copper, US$20.00/lb molybdenum, and US$45.00/oz silver, and incorporate assumptions for metallurgical recoveries, payable metal factors, smelting and refining charges, transportation costs, and royalties. Hence the CuEq calculation is essentially based on net smelter return (NSR) values. NSR for each metal is estimated by applying metallurgical recoveries, payable factors, metal prices, and applicable smelting, refining, transportation, and penalty charges to the in-situ metal grades. CuEq grades are derived using a linear regression relationship established between copper grade and copper NSR, and then calculated by substituting total NSR (Cu + Mo + Ag) for copper NSR in the regression equation. The simplified formula is expressed as CuEq (%) = Cu (%) + 3.40327 × Mo (%) + 0.00008 × Ag (g/t)

Qualified Person

The scientific and technical content of this news release has been reviewed and approved by Mr. Bernard-Olivier Martel, P. Geo. (OGQ 492), an independent “qualified person” as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”).

Quality Assurance / Quality Control

Mineralized intervals reported herein are calculated using an average 0.12% CuEq lower cut-off over contiguous 20-metre intersections (shorter intervals as the case may be at the upper and lower limits of reported intervals). Intervals of 10 metres or less are generally not reported unless considered material. True widths are estimated at 80 – 90 % of the reported core length intervals.

Osisko Metals adheres to a strict QA/QC program for core handling, sampling, sample transportation and analyses, including insertion of blanks and standards in the sample stream. Drill core is drilled in HQ or NQ diameter and securely transported to its core processing facility on site, where it is logged, cut and sampled. Samples selected for assay are sealed and shipped to ALS Canada Ltd.’s preparation facility in Sudbury. Sample preparation details (code PREP-31DH) are available on the ALS Canada website. Pulps are analyzed at the ALS Canada Ltd. facility in North Vancouver, BC. All samples are analyzed by four acid digestion followed by both ICP-AES and ICP-MS for Cu, Mo and Ag.

About Osisko Metals

Osisko Metals Incorporated is a Canadian exploration and development company creating value in the critical metals sector, with a focus on copper and zinc. The Company acquired a 100% interest in the past-producing Gaspé Copper mine from Glencore Canada Corporation in July 2023. The Gaspé Copper mine site is located near Murdochville in Québec's Gaspé Peninsula. The Company is currently focused on resource expansion of the Gaspé Copper deposits, with current pit-constrained Measured and Indicated Mineral Resources of 1.83 Bt averaging 0.32% CuEq and Inferred Mineral Resources of 239 Mt averaging 0.46% CuEq (in compliance with NI 43-101). For more information, see Osisko Metals' April 14, 2026 news release entitled “Osisko Metals Announces Significant Increase in Mineral Resource at Gaspé Copper”. Gaspé Copper hosts the largest undeveloped copper resource in eastern North America, strategically located near existing infrastructure in the mining-friendly province of Québec.

In addition to the Gaspé Copper project, the Company is working with Appian Capital Advisory LLP through the Pine Point Mining Limited joint venture to advance one of Canada's largest past-producing zinc mining camps, the Pine Point project, located in the Northwest Territories. The current mineral resource estimate for the Pine Point project consists of Indicated Mineral Resources of 49.5 Mt averaging 5.52% ZnEq and Inferred Mineral Resources of 8.3 Mt averaging 5.64% ZnEq (in compliance with NI 43-101). For more information, see Osisko Metals' June 25, 2024 news release entitled “Osisko Metals releases Pine Point mineral resource estimate: 49.5 million tonnes of indicated resources at 5.52% ZnEq”. The Pine Point project is located on the south shore of Great Slave Lake, NWT, close to infrastructure, with paved road access, an electrical substation and 100 kilometres of viable haul roads.

For further information on this news release, visit www.osiskometals.com or contact:

Don Njegovan, President
Email: info@osiskometals.com
Phone: (416) 500-4129

Cautionary Statement on Forward-Looking Information

This news release contains “forward-looking information” within the meaning of applicable Canadian securities legislation based on expectations, estimates and projections 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, 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 forward-looking information pertaining to, among other things: the tax treatment of the FT Units; the timing of incurring the Qualifying Expenditures and the renunciation of the Qualifying Expenditures; the ability to advance Gaspé Copper to a construction decision (if at all); the ability to increase the Company's trading liquidity and enhance its capital markets presence; the potential re-rating of the Company; the ability for the Company to unlock the full potential of its assets and achieve success; the ability for the Company to create value for its shareholders; the advancement of the Pine Point project; the anticipated resource expansion of the Gaspé Copper system and Gaspé Copper hosting the largest undeveloped copper resource in eastern North America.

Forward-looking information is not a guarantee of future performance and is based upon a number of estimates and assumptions of management, in light of management's experience and perception of trends, current conditions and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances, including, without limitation, assumptions about: the ability of exploration results, including drilling, to accurately predict mineralization; errors in geological modelling; insufficient data; equity and debt capital markets; future spot prices of copper and zinc; the timing and results of exploration and drilling programs; the accuracy of mineral resource estimates; production costs; political and regulatory stability; the receipt of governmental and third party approvals; licenses and permits being received on favourable terms; sustained labour stability; stability in financial and capital markets; availability of mining equipment and positive relations with local communities and groups. Forward-looking information involves risks, uncertainties and other factors that could cause actual events, results, performance, prospects and opportunities to differ materially from those expressed or implied by such forward-looking information. Factors that could cause actual results to differ materially from such forward-looking information are set out in the Company's public disclosure record on SEDAR+ (www.sedarplus.ca) under Osisko Metals' issuer profile. Although the Company believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information, which only applies as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. The Company disclaims any intention or obligation to update or revise any forward- looking information, whether as a result of new information, future events or otherwise, other than as required by law.

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