ATERRA drills 284 m grading 0.64% CuEq at Totora project

Toronto, Ontario--(Newsfile Corp. - July 16, 2026) - ATERRA Metals Inc. (CSE: ATC) (OTCQB: CSSCF) ("ATERRA") is pleased to report Phase I drill assay results from its Totora Cu/Au Project located in the Dos Amigo Mining District, 15 kilometres south of Tintina Mines' Domekyo Sulfurous development project. Highlights AFROD01 returned 284 metres grading 0.64% copper equivalent ("CuEq") from surface at the Frontera Cu/Au Deposit (0.41% Cu and 0.27 grams per tonne ("g/t") gold)  including 180 metres grading 0.71% CuEq (0.48% Cu and 0.28 g/t Au) including 70 metres grading 0.82% CuEq (0.56% Cu and 0.32 g/t Au) ATOD01 returned 194 metres grading 0.41% CuEq (0.35% Cu and 0.11 g/t Au) collared on the Totora Porphyry Drilling confirmed the presence of significant copper and gold mineralization at both the Frontera Deposit and nearby Totora Cu/Au Porphyry highlighting the potential of the Totora Cu/Au Project   NOTES: Intervals were composited using a 0.25% CuEq cut-off grade including no more than 10-metres of internal sub-0.25% CuEq material. Intervals represent downhole lengths as insufficient data is available to estimate true widths.

See "NI 43-101 Disclosure" section in this release for details on the CuEq grade calculation. "The assay results from our Phase I drill program are impressive with drill holes confirming that both the Frontera and Totora copper-gold porphyries have the potential to host significant mineral resources," said Carl Hansen, CEO of ATERRA. "The Totora Project lies in the Dos Amigo Mining District which benefits from excellent regional infrastructure, low elevations and proximity to water.

Considering these benefits, the District has seen significant interest with the recent Sumitomo / Gignac family investment in Tintina Mines, with their Domekyo Sulfurous development project, and Hot Chili's La Verde Cu/Au discovery. With a