Altamira Gold lifts Maria Bonita indicated resources to 403,877 oz, inferred to 908,477 oz

• Altamira Gold reported a higher mineral resource estimate at its Maria Bonita porphyry deposit in Brazil’s Cajueiro district, effective Sept. 16, 2026.
• Indicated open-pit resources rose to 25 Mt at 0.50 g/t gold, containing 403,877 oz, using a 0.24 g/t cut-off.
• Inferred resources increased to 70 Mt at 0.41 g/t gold, containing 908,477 oz, up 150% versus the 2025 estimate.
• Optimized pit shell implies about a 0.4:1 waste-to-ore ratio, based on a US$ 3,300/oz gold price assumption.
• At a 0.5 g/t cut-off, higher-grade resources total 9 Mt indicated at 0.75 g/t, 11 Mt inferred at 0.80 g/t; drilling continues westward.

Disclaimer: This news brief was created by Public Technologies (PUBT) using generative artificial intelligence. While PUBT strives to provide accurate and timely information, this AI-generated content is for informational purposes only and should not be interpreted as financial, investment, or legal advice. Altamira Gold Corp. published the original content used to generate this news brief via Newsfile (Ref. ID: 202609210829NEWSFILECNPR____20260921_315137_1) on September 21, 2026, and is solely responsible for the information contained therein.