Contango Silver & Gold (CTGO) investor relations material

Updated mineral resource estimate

• Indicated silver-equivalent resources increased 93% to 89.55 million ounces, with 7.66 Mt at 363 g/t AgEq; inferred resources now 64.92 Moz AgEq at 320 g/t AgEq.

• Resource growth driven by 370 new drill holes (175,264 meters) and a revised geological model integrating advanced 3D modeling.

• Indicated silver ounces rose to 58.7 Moz Ag, with significant increases in gold, copper, lead, and zinc inventories.

• The resource estimate is based on a comprehensive database of 1,873 drill holes totaling over 433,934 meters across eight deposits.

• None of the 2026 drilling (over 50,000 meters) is included in this update; a further update is planned for H1 2027.

Geological and technical framework

• The project is hosted in the Stikine Terrane and Stewart Complex, with mineralization styles varying between the Dolly Varden and Homestake areas.

• Updated geological modeling involved 34 domains and 23,264 assay intervals from 947 drill holes.

• The geological model was modernized using Leapfrog Geo, ensuring consistency and rapid future updates.

• Data was audited and certified in April 2026; 2026 drilling will be included in the next update.

Estimation methodology and assumptions

• Seven deposits were modeled using Leapfrog Geo with domain-specific compositing and grade capping; interpolation used inverse-distance-cubed weighting.

• Silver-equivalent calculations use commodity prices: $53/oz Ag, $3,500/oz Au, $5.00/lb Cu, $1.25/lb Zn, $0.90/lb Pb, with metallurgical recoveries integrated.

• The mining concept is mechanized underground extraction, considering site access, processing, and permitting.

• The estimate does not establish reserves, capital costs, or economic metrics.