Tier One Silver Reports Additional High-Grade Intercepts, Including 1 Metre of 448.2 g/t Ag and 0.37 g/t Au, from Phase 2 Drilling at Curibaya

Vancouver, British Columbia--(Newsfile Corp. - June 11, 2026) - Tier One Silver Inc. (TSXV: TSLV) (OTCQB: TSLVF) (FSE: TOV0) ("Tier One" or the "Company") is pleased to announce the second and final round of assay results from its Phase 2, eight diamond core drill program at its high-grade Curibaya epithermal silver-gold-copper project located in Tacna, Peru. All four of the final holes drilled in the Cambaya I corridor intercepted silver and gold with highlights including 1.0 metre ("m") of 448.2 grams per tonne ("g/t") silver ("Ag") and 0.37 g/t gold ("Au"), within a broader interval of 4.0 m of 136.2 g/t Ag and 0.15 g/t Au, in hole 26CUR-023, the seventh hole of the program. These results complement previously released intercepts and further define the scale and continuity of precious metal mineralization within the Cambaya I corridor and across the Curibaya project area drilled to date.

Phase 2 drilling, conducted through the Company's wholly owned Peruvian subsidiary, Magma Minerals S.A.C., totaled 1,133.6 m and represents a focused test of shallow levels along a limited portion of the Cambaya I corridor (Figure 1). Results collectively reinforce the presence of a robust high-grade silver-gold epithermal system which was originally identified in the Company's 2021 surface sampling and inaugural drill campaign. All results from Phase 2 drilling have now been received and are summarized in Table 1 below.

Building on the initial four holes of Phase 2 drilling released April 21, 2026, the remaining results provide additional confidence in the geometry and continuity of mineralized structures, while also identifying new high-grade shoots within the corridor. Located more than 1 kilometre ("km") away from Phase 1 drill hole 21CUR-016, which reported 1.5 m with a grade of 1128.7 g/t Ag and 1.04 g/t Au (see news release dated February 14, 2022), the additional eight holes drilled in this 2026 campaign have expanded the mineralized footprint across 6 km of mineralized corridors and structures. Mineralization intersected in Phase 2 aligns with surface geochemical anomalies (see news releases dated September 26, 2022 and April 21, 2026) and confirms that high-grade zones persist below surface and remain open in multiple directions, with further drilling warranted and required to test expansion and initial resource inferred potential.

Peter Dembicki, CEO and President of Tier One commented, "We are pleased with the latest results from our Phase 2 drill program. The Cambaya I corridor has provided exceptional high-grade silver-gold results, once again proving the endowment of our Curibaya project. We are currently analyzing the results to determine the location of our next phase of drilling. Each result we receive provides valuable information on the epithermal system, and where to focus our next phase of drilling."

Figure 1: Illustrates Phase 2 drill hole main intervals and the location of Cambaya I and II Corridors in relation to the Corridors drilled in 2021 Phase 1.

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Table 1. Cambaya I Phase 2 Drilling Intercept Highlights

Geological Interpretation

Seven of the eight Phase 2 holes have silver and gold present, four of which include intercepts with more than 150 g/t silver plus a gold component, and holes 22, 23 and 24 also include intercepts at shallow depths. The latest results extend and confirm high-grade silver-gold mineralization along a 6 km corridor system at the Curibaya project. Drilling to date completed in both Phase I (see news releases between November 2021 and February 2022) and Phase II has demonstrated the project's consistency with 11 holes, being 45% of the 24 completed holes, containing more than 150 g/t silver plus a gold component. In addition to the 6 km of corridors and structures, the project is notable as it also hosts veins ranging from 0.5 to 1.5 m in width with dilatational zones (ore shoots) up to 7 m wide, containing grades of 272.3 g/t Ag and 0.33 g/t Au (hole 21CUR-016, see news release dated February 14, 2022).

The Company interprets these strong surface precious metals expressions as a potential link to a deep hydrothermal source that may be rich in copper and possibly gold. This hypothesis is supported by the presence of a skarn area south of the Dome Complex and surface copper values ​​ reaching up to 6.12% discovered during a 2023 surface program at the Company's Del Filo target (see news release dated September 11, 2023 and Figures 1 and 2). In addition, the lower base metals geochemical values encountered in Phase 2 drilling, 136 parts per million ("ppm") lead ("Pb") and 130 ppm zinc ("Zn"), in comparison with the base metals values encountered in Phase 1 drilling, 1,757 ppm Pb and 2,608 Zn, demonstrates that Cambaya I and Cambaya II, one of the identified corridors that has not yet been drilled, are located in the upper part of an epithermal system. Given the location of Curibaya, which is located in the Paleocene Porphyry trend that hosts significant porphyry copper deposits like Quellaveco, Toquepala, Cuajone and Cerro Verde, in combination with the occurrence of the silver-gold structures in the upper part of the project and copper showings in other areas, Tier One's technical team believes that Curibaya could represent a complete system, with both epithermal and porphyry components.

Figure 2: Provides photos of Del Filo target breccia, with samples up to 42.2 g/t Au, 651 g/t Ag and 6.12% Cu related to silicified fragments with copper oxides.

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Next Steps at the Curibaya Project

The Company has recently commenced work on an Environmental Impact Study ("EIA-sd") permit that, once obtained, would allow the Company to drill more than 200 drill holes and continues its ongoing community engagement working towards a further renewal of its social access agreement.

Subject to funding and ongoing interpretation of the recent drill results, preliminary follow up exploration will include conducting more detailed geological and structural mapping of the multiple mineralized corridors to interpret potential open spaces and fault displacements. The Company's next phase of drilling is likely to focus on the Cambaya II area, one of the identified corridors that has not yet been tested below surface, before following up on each of the six identified corridors with in-fill drilling to gather more data at depth. This infill phase will also target the possible porphyry copper source at depth (see news releases January 30, 2023, and September 11, 2023).

Beyond the area where drilling to date has been focused, the Company is planning an exploration campaign consisting of enhanced mapping, chip sampling, exploration channels, test pits, and channel samples in Zones 1 and 3 (see Figure 3 below and news releases dated June 12, 2023 and September 11, 2023). Limited field work completed in these areas has encountered the highest copper and gold BLEG grades identified on the project to date. Future programs will aim to identify new targets for drilling in future phases.

Figure 3: Illustrates location of Zone 1 and Zone 3 where high-grade copper - gold BLEG anomalies were found.

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Qualified Person

Christian Rios (SVP of Exploration), P.Geo, is the Qualified Person who has reviewed and approved the technical contents of this press release.

ON BEHALF OF THE BOARD OF DIRECTORS OF TIER ONE SILVER INC.

Peter Dembicki President, CEO and Director

About Tier One Silver

Tier One Silver is an exploration company focused on creating value for shareholders and stakeholders through the discovery of silver, gold and copper deposits in South America. The Company is focused on its flagship exploration project, Curibaya, but continues to investigate other potential projects of merit. The Company's management and technical teams have a strong track record in raising capital, discovery and monetization of exploration success.

Channel Sampling

Analytical samples were taken from each 1-metre interval of channel floor resulting in approximately 2-3 kg of rock chips material per sample. Collected samples were sent to ALS Lab in Arequipa, Peru for preparation and then to Lima, Peru for analysis. All samples are assayed using 30 g nominal weight fire assay with atomic absorption finish (Au-AA25) and multi-element four acid digest ICP-AES/ICP-MS method (ME-MS61). Where MS61 results were greater or near 10000 ppm Cu, 10000 ppm Pb or 100 ppm Ag the assays were repeated with ore grade four acid digest method (Cu, Pb, Ag-OG62). Where OG62 results were greater or near 1500 ppm Ag the assay were repeated with 30 g nominal weight fire assay with gravimetric finish (Ag-GRA21). QA/QC programs for channel samples using internal standard and blank samples; field and lab duplicates indicate good overall accuracy and precision.

Silver equivalent grades (AgEq), which were use for interval selection only, were calculated using a $1300/oz gold price and $18/oz silver price. AgEq = Ag (ppm) + Au (ppm) * (Ag $/troy oz/Au $/troy oz). No metallurgy recoveries were used for the AgEq calculation.

Main Interval - AgEq (Ag, Au) intervals at 25 ppm (minimum 5 m, max consecutive dilution 6 m)
Sub-Interval - AgEq (Ag, Au) intervals at 75 ppm (minimum 1 m, max consecutive dilution 2 m).

True widths of mineralization are unknown due to the unknown mineralized zones orientation.

Drilling

Analytical samples were taken by sawing HQ or NQ diameter core into equal halves on site and sent one of the halves to ALS Lab in Arequipa, Peru for preparation and then to Lima, Peru for analysis. All samples are assayed using 30 g nominal weight fire assay with atomic absorption finish (Au-AA25) and multi-element four acid digest ICP-AES/ICP-MS method (ME-MS61). Where MS61 results were greater or near 10,000 ppm Cu, 10,000 ppm Pb or 100 ppm Ag the assays were repeated with ore grade four acid digest method (Cu, Pb, Ag-OG62). Where OG62 results were greater or near 1,500 ppm Ag the assay were repeated with 30 g.

QA/QC programs for 2026 core samples using company and lab duplicates, standards and blanks indicate good accuracy and precision in a large majority of standards assayed.

Silver equivalent grades (AgEq), which were used for interval selection only, were calculated using silver price of US$18/oz and gold price of US$1,300/oz. Metallurgical recoveries were not applied to the silver equivalent calculation.

Main Interval - AgEq (Ag, Au) intervals at 25 ppm (minimum 5 m, max consecutive dilution 6 m)
Sub-Interval - AgEq (Ag, Au) intervals at 75 ppm (minimum 1 m, max consecutive dilution 2 m)

True widths of mineralization are unknown due to the unknown mineralized zones orientation.

Forward-Looking Information and General Cautionary Language

This news release contains forward-looking statements and forward-looking information within the meaning of Canadian securities legislation (collectively, "forward-looking statements") that relate to the Company's current expectations and views of future events in connection with the Phase 2 drill program, the potential of the mineralization and discovery, viability or expansion of any mineralization, including a potential copper source and future drill plans including the progress of expanded permits and financing to fund such work. Forward-looking statements are not historical facts and therefore may involve estimates, assumptions and uncertainties which could cause actual results or outcomes to differ materially from those expressed in such forward-looking statements. No assurance can be given that these expectations will prove to be correct and such forward-looking statements included in this news release should not be heavily relied upon. These statements speak only as of the date of this news release.

Readers should refer to the risks discussed in the Company's continuous disclosure filings with the Canadian Securities Administrators including its most recent Annual Information Form and Management's Discussion & Analysis, available at www.sedarplus.ca.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

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Source: Tier One Silver Inc.