Company Announcements

VANCOUVER, BC , Sept. 9, 2025 /CNW/ -GR Silver Mining Ltd.("GR Silver Mining" or the "Company") (TSXV: GRSL) (OTCQB: GRSLF) (FRANKFURT: GPE) is pleased to announce that it has received a key 5-year drill permit for the San Marcial Area authorizing additional step-out and exploration drilling in an extensive area surrounding the current NI 43-101 Resource  Area. The five-year Informe Preventivo ("IP") issued by the Secretaría de Medio Ambiente y Recursos Naturales ("SEMARNAT"), Mexico will allow for the drilling of step-out and exploration holes at 46 new drill sites in the San Marcial Area.

The IP does not limit the total metreage, nor number of drill holes, that can be drilled in the 46 newly approved drill sites. This provides the Company with flexibility for multiple drill hole orientations within the three defined target areas shown in Figure 1, as well as the ability to explore new targets along the edges of the chargeability geophysical anomaly.

This is the first time that the Company has been granted such a long-term drill permit, which bodes well for its initiatives to expand known mineralization and support resource growth, in addition to exploring the recently discovered silver-rich epithermal system sitting on the edge of a regional-scale porphyry intrusive related geological setting. Receipt of the drill permit is also evidence that GR Silver Mining's persistent and patient efforts, as well as constructive engagement with Mexican authorities, has been effective in successfully advancing the Plomosas Silver Project.

The receipt of the permit allows the Company to proceed with the following activities in the coming months:

1. Complete the final 3 drill holes of the 2025 summer drilling program as outlined in the September 3 press release. Upon completion and receipt of all assays, incorporate all drilling data into the 3D model, including recent discoveries such as SMS25-09 (75m at 293 g/t AgEq)¹. This will guide the planning of future step-out drilling in the San Marcial Area.
2. Conduct additional geophysical investigations, including potential down-hole geophysical surveys in key drill holes within the Resource Area. These surveys will assist in modeling and targeting high-grade silver mineralized hydrothermal breccias beneath the existing Resource Area. Modern down-hole geophysics will serve as an alternative to support directional drilling, increasing the likelihood of intersecting the epithermal system down-dip from the Resource Area boundaries.
3. Post-completion of the above activities, the Company will proceed with further steps in the negotiations with third-party drilling companies for follow-up drilling programs at the San Marcial Area.
4. Advance additional drilling under the new drill permit, using the updated 3D model and geophysical surveys scheduled for the summer of 2025 and continuing throughout the rest of the year.

The  drilling results in the summer 2025 drilling phase have expanded the San Marcial mineralized footprint, extending high-grade mineralization a further 100 metres below the previous resource outline. Within these broad zones of silver-dominant, high-grade mineralization, a transition with depth has been observed, marked by changes in alteration and lithology, which supports our interpretation of a robust epithermal system hosted along the northern margin of a large regional-scale porphyry intrusive complex. These results validate our exploration model and highlight the significant potential for future resource growth.

Qualified Person
The Qualified Person under National Instrument 43-101 Standards of Disclosure for Mineral Projects for this news release is Marcio Fonseca, P. Geo., President & CEO for GR Silver Mining, who has reviewed and approved its contents.

About the Plomosas Project
The Plomosas Project, including the recent high-grade silver discovery in the San Marcial SE Area, is progressing in 2025 as an emerging high-grade silver district located in southwestern edge of the Sierra Madre Occidental, Sinaloa, Mexico. The Plomosas Project, covering 7,823 ha, including the historical Plomosas Underground mine. benefits from mine infrastructure, road access and existing permits associated with past-producing mining sites. The district contains intermediate to low-sulfidation epithermal silver and gold mineralization, hosted in hydrothermal breccias and veins. Recent success in exploration and drilling has delineated wide, high-grade, shallow hydrothermal breccias in the San Marcial Area, including the SE Area discovery, where step-out drilling is underway in 2025, aiming for continuous resource growth. At the historical Plomosas Mine, where Grupo Mexico operated the underground mine from 1985 to 2000, exploration, underground sampling and metallurgical programs are being conducted to support future decisions regarding the implementation of a Bulk Sampling Test Mining Program

About GR Silver Mining Ltd.
GR Silver Mining is a Canadian-based, Mexico-focused mineral exploration company engaged in cost-effective silver-gold resource expansion on its 100%-owned assets, located on the eastern edge of the Rosario Mining District, in the southeast of Sinaloa State, Mexico. GR Silver Mining controls 100% of the Plomosas Project, including the former Plomosas underground mine and wide, high-grade silver mineralized zones at the San Marcial Area. Recent discoveries in the 78 km² of highly prospective, advanced-stage exploration concessions position the Company well for resource expansion at the Plomosas Project.

GR Silver Mining Ltd.
Márcio Fonseca, President & CEO                    

Cautionary Statement Regarding Forward-Looking Information
This press release contains "forward-looking statements" within the meaning of applicable Canadian securities legislation and information that are based on the beliefs of management and reflect the Company's current expectations. When used in this press release, the words "estimate", "project", "belief", "anticipate", "intend", "expect", "plan", "predict", "may" or "should" and the negative of these words or such variations thereon or comparable terminology are intended to identify forward-looking statements and information. Such statements and information reflect the current view of the Company. Risks and uncertainties may cause actual results to differ materially from those contemplated in those forward-looking statements and information. By their nature, forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements, or other future events, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements.

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 press release.

SOURCE GR Silver Mining Ltd.