Mr. Carl Hansen reports

ATERRA ANNOUNCES COMPLETION OF TOTORA PHASE I DRILL PROGRAM

Aterra Metals Inc.'s Totora Cu-Au (copper-gold) project phase I drill program has been finished with a total of 2,745.6 metres of drilling completed: 1,571.5 metres of reverse circulation and 1,174.1 metres of diamond drilling (Table 1). The Totora Cu-Au project is located within the Dos Amigos mining district, 60 kilometres south of the city of Vallenar, Region III, Chile, and 15 kilometres south of Tintina Mines' Domeyko Sulfuros project.

The phase I drilling program largely targeted the Totora and Algarrobilla Cu-Au porphyries with a single diamond drill collared into the Frontera Cu-Au deposit. The program comprised a combination of confirmational drilling in preparation for a resource estimate as well as exploration drilling to test the extensions of the known mineralized porphyries.

"The phase I Totora drill program was safely completed on schedule," said Carl Hansen, chief executive officer of Aterra, "with drilling confirming the presence of pyrite and chalcopyrite mineralization at the Totora, Algarrobilla and Frontera porphyry systems. Unfortunately, due to a significant number of exploration and development programs currently under way in Chile, the assay laboratories are backed up and results are delayed four to six weeks. The delays should not impact our plans to have our first Totora Cu-Au project resource estimate available during the third quarter of 2026."

Frontera Cu-Au deposit

The Frontera Cu-Au deposit hosts historic resources (Table 2) of 16 million indicated tonnes grading 0.56 per cent copper equivalent (CuEq) (0.38 per cent copper and 0.22 gram per tonne gold) and 34 million inferred tonnes grading 0.54 per cent CuEq (0.36 per cent copper and 0.22 gram per tonne gold). The historical resource estimate was based on 16,175 metres of dominantly reverse circulation drilling, completed in 2013. Aterra completed a single diamond drill hole into the Frontera to provide geological information and confirmatory assay data necessary for the preparation of a National Instrument 43-101-compliant resource estimate. The diamond drill hole confirmed the presence of a mineralized quartz diorite porphyry.

Research Capital advisory agreement

On March 26, 2026, Aterra announced that it had engaged Research Capital Corp. (RCC) as a financial adviser for a period of three months. In consideration of RCC's engagement, Aterra will issue RCC a total of 5.75 million common shares of Aterra, to be paid in three monthly tranches. The second tranche of 1,916,666 shares was issued effective May 26, 2026. The securities were issued at a deemed price of 3.27 cents per share for total deemed consideration of $62,674.97. The shares issued are subject to a statutory hold period of four months (until Aug. 27, 2026). Upon issuance of the shares to RCC, Aterra will have 351,874,466 issued and outstanding common shares.

National Instrument 43-101 disclosure

Qualified person: As defined by National Instrument 43-101 of the Canadian Securities Administrators, the qualified person for Aterra Metals is Francisco Bravo, a resident of Santiago, Chile. As Aterra's chief geologist, Mr. Bravo is considered "not independent" as the term is defined by NI 43-101. Mr. Bravo, a public registered person for Reserves and Resources Ndegree 515, in Chile, and registered in the Colegio de Geologos de Chile under N 725 degrees, has reviewed and approved the technical information contained in this press release.

Copper equivalent estimation: Copper equivalent (CuEq) grades were estimated using a copper price of $4.00 (U.S.) per pound and a gold price of $3,500 (U.S.) per ounce ($112.53 (U.S.) per gram). CuEq grades are estimated using the following formula: CuEq per cent equals (((Au grade multiplied by 0.85 multiplied by 112.53) divided by 4.00 divided by 2,204.6) multiplied by 100) plus (Cu grade multiplied by 0.85).

Regulatory requirements for disclosure of CuEq grades require an estimation of metallurgical recoveries in the situation where no metallurgical testwork has been completed. Aterra estimates copper recoveries of 85 per cent and gold recoveries of 85 per cent. Note that the actual recoveries will likely vary from those used in the estimation of the CuEq grades.

Historical results: Aterra's qualified person has not done sufficient work to make the Frontera Deposit resource estimate current and Aterra does not consider the historical resource a current National Instrument 43-101-compliant resource estimate. The reader is cautioned against relying on the accuracy of the historical results presented herein. Aterra considers all historical results relevant as those results will be used as a guide to plan future exploration programs: Aterra considers the data to be reliable for these purposes.

About Aterra Metals Inc.

Aterra is a mineral exploration company focused on exploration opportunities in Chile. Aterra's team of successful exploration professionals is dedicated to the discovery of mineral deposits that can be progressed into economically viable development projects, creating value for all stakeholders.

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