Onyx Gold Expands Argus North Discovery Footprint - 208 m of 2.3 g/t Au, Including 25 m of 5.2 g/t AuBest Intersection to Date from Argus NorthVancouver, British Columbia--(Newsfile Corp. - November 17, 2025) - Onyx Gold Corp. (TSXV: ONYX) (OTCQX: ONXGF) ("Onyx" or the "Company") is pleased to report another strong drill intercept from the Argus North Zone ("Argus North") as part of the Company's ongoing drill program (the "Program") at its 100%-owned Munro-Croesus Project ("Munro-Croesus" or the "Project"), located 75 km east of Timmins, Ontario.The latest results come from hole MC25-232, which was designed to test a newly defined northeast-trending structural corridor beneath the Argus North outcrop. This target emerged from detailed geological mapping and surface channel sampling that indicated a strong structural control on higher-grade gold distribution (see news release dated October 7, 2025). MC25-232 successfully confirmed this interpretation, delivering the widest continuous interval of gold mineralization encountered at Argus North to date, returning 208.0 meters ("m") grading 2.3 grams per tonne gold ("g/t Au"), while extending the southern footprint of the zone by an additional 50 metres.Step-out drilling continues to systematically expand the Argus North mineralized system along strike and to depth. Recent holes have returned multiple broad and high-grade intercepts (see news releases dated April 10, June 26, July 23, September 3, October 7, and October 22, 2025), including 69.6 m grading 3.4 g/t Au in the initial discovery hole MC25-232.New Highlights from Argus North208.0 m grading 2.3 g/t Au, in drill hole MC25-232, including 54.4 m grading 3.3 g/t Au, including8.0 m grading 5.0 g/t Au, and4.0 m grading 5.8 g/t Au2.0 m grading 5.5 g/t Au4.0 m grading 4.3 g/t Au24.9 m grading 5.2 g/t Au, including12.0 m grading 7.2 g/t Au, and3.0 m grading 7.5 g/t AuOngoing step-out drilling at Argus North, combined with mechanical stripping and channel sampling, has continued to demonstrate wide intervals of gold mineralization over >150 meters of strike length and from surface to >350 meters vertically. The Argus North Zone remains open along strike, down-dip, and down-plunge. The Company has completed 81 drill holes to date (assays announced for 37 holes) completing the previously announced 25,000 m Phase II drill program and announcing a fully-funded 50,000 m Phase III drill program utilizing three drill rigs (See Company news release dated November 13, 2025). "The 208 metres intersection grading 2.3 g/t gold in MC25-232 represents another significant step forward at Argus North delivering our broadest zone of continuous mineralization to date," said Brock Colterjohn, President & CEO. "Importantly, these results deliver robust gold continuity close to surface and extends the system 50 meters to the south, further demonstrating the scale and strength of this growing discovery. The consistent mineralization with multiple higher-grade sub-intervals continues to validate our evolving structural interpretation and points to substantial room for expansion. With a fully funded additional 50,000-metre drill program now underway, we are well positioned to accelerate growth at Argus North and to systematically test the broader structural corridor across the Munro-Croesus Project."Discussion of 2025 Argus North Drill ResultsThe Argus North Zone is located on the western half of the Munro-Croesus Project, approximately 150 metres north of the regional Pipestone Fault, a major structural corridor that hosts several significant gold deposits in the Timmins camp. The discovery hole at Argus North, MC24-163, was reported earlier this year, and returned 69.6 m grading 3.4 g/t Au, including 34.5 m grading 5.4 g/t Au and 9.5 m grading 13.9 g/t Au (see Company news release dated April 10, 2025). Gold mineralization at Argus North is distinguished by both broad zones (50 m to over 100 m) of +1 g/t Au mineralization containing multiple continuous higher-grade sub-intervals. Notable recent high-grade intercepts include 17.0 m grading 5.3 g/t Au in hole MC25-168, 18.7 m grading 5.2 g/t Au in MC25-171, 5.2 m grading 5.1 g/t Au and 6.6 m grading 4.2 g/t Au in MC25-178, 4.0 m grading 6.6 g/t Au in MC25-179, and 4.0 m grading 5.9 g/t Au in MC25-180. Geologically, the high-grade sub-intervals at Argus North are closely associated with zones of strong albitization and silicification, pyritic stringers, and localized porphyritic intrusions within variolitic basalt and volcanic breccias cut by dominant northeast-trending faults and associated fractures. This combination of alteration and structural preparation is interpreted to be a key control on gold deposition. Drilling to date demonstrates excellent vertical continuity of mineralization, now traced from surface to over 350 meters depth, with the system remaining open along strike, down-dip and down-plunge.The evolving interpretation of the potential controls on gold mineralization a