GR Silver Drill Program Delivers High-Grade Intercepts: 35.45 m at 311 g/t Ag, including 0.4 m at 4,232 g/t Ag in the SE Area, and 2.15 m at 1,164 g/t Ag, 0.6% Cu, and 0.37% W in the Parallel Breccia Target

GR Silver Mining Ltd. (GRSL) has released assay results from the 2026 San Marcial step-out program at its Plomosas project in Mexico. The company clarified that the release consists of drill results rather than a resource estimate or economic study.

In the SE Area, hole SMS26-19 returned 35.45 m true width at 311 g/t Ag from 339.85 m downhole. This interval included higher-grade segments: 0.4 m true width at 4,232 g/t Ag, 1.35 m true width at 996 g/t Ag, 0.35 m true width at 1,901 g/t Ag, and 0.5 m true width at 2,017 g/t Ag. Associated metals in the composite were 0.03 g/t Au, 0.2% Pb, and 0.4% Zn.

Other intercepts from the SE Area include: * SMS26-16: 7.6 m true width at 50 g/t Ag from 264.8 m, with 0.04 g/t Au and 0.1% Zn. * SMS26-18: 9.7 m true width at 11 g/t Ag from 232.2 m and 6.9 m true width at 11 g/t Ag from 282.85 m.

Results from the Parallel Breccia Target include: * SMS26-17: 2.15 m true width at 1,164 g/t Ag, 0.6% Cu, 0.37% W, and 0.10 g/t Au from 104.8 m. * SMS26-11: 0.5 m at 23 g/t Ag, though the company noted mineralization is poorly developed at this location.

The program has drilled 7,756 m in 25 holes, with assays pending from six holes. Two additional holes are planned on the SMS26-19 section to test up to 500 m down-dip. An update to the mineral resource estimate is targeted for mid-2027.

The release also referenced prior holes, including: * SMS26-04: 45.1 m true width at 1,623 g/t Ag, including 8.25 m at 8,579 g/t Ag. * SMS26-06/07: 21.9 m at 168 g/t Ag, including 6.15 m at 447 g/t Ag. * SMS25-10A: 9.0 m at 374 g/t Ag, 0.3% Cu, and 0.59% W.

No cutoff grade is stated for the results, which are described as uncut and undiluted with true widths provided.

GR Silver Mining Ltd. (GRSL) is an explorer and developer with a 2023 Mineral Resource Estimate of approximately 134 moz AgEq, divided roughly evenly between 68 moz AgEq at San Marcial and 66 moz AgEq at Plomosas. The company currently generates no revenue, making drill results a primary driver of its equity value.

Prior-period financial data not disclosed in today’s release indicates the company held C$26.0 million in cash as of June 30, 2026, with no debt and working capital of approximately C$26.0 million. With 509.4 million shares outstanding, the company’s market capitalization stands at about C$117.2 million at a share price of C$0.23, while its enterprise value is roughly C$91 million.

The latest release marks a material improvement over the step-outs reported in September and July. The SMS26-19 intercept demonstrates significantly stronger grade-times-width and extends the SE Area system down-dip. However, in terms of grade or gram-metres, the result is not materially new compared to the May SMS26-04 anchor.

The stock traded near C$0.30 before the May 19 release, spiked to approximately C$0.43, and then round-tripped to C$0.23 by November 11, near the C$0.22 52-week low. The current share price does not appear to assume a repetition of the May bonanza grade.

Because the previous high grade is not embedded in the current valuation, the result is not viewed as a priced disappointment. The stock is trading near its lows, and the SMS26-19 result represents the strongest step-out since May, with the parallel breccia adding further optionality. The outcome supports resource growth and continuity but does not yet convert to tonnes, mineable grades, or an economic study. It is considered a material positive step-out rather than a resource or net asset value event.

GR Silver Mining Ltd. (TSXV: GRSL, OTCQX: GRSLF) is a Canadian-based mineral exploration company focused on assets in Mexico. The firm controls 100% of the Plomosas project, which covers 7,823 hectares on the border of Durango and Sinaloa. The company’s assets include the San Marcial high-grade silver discovery, specifically the SE Area, and the former Plomosas underground mine, which features existing infrastructure and permits.

In a 2023 mineral resource estimate, the company reported approximately 134 moz AgEq in total resources, comprising roughly 68 moz AgEq at San Marcial and 66 moz AgEq at Plomosas. The development path includes a 20,000-meter San Marcial step-out program, an updated mineral resource estimate targeted for mid-2027, an integrated preliminary economic assessment, and a BSTM or pilot-plant evaluation at Plomosas.

As of June 30, 2026, the company’s balance sheet showed C$26.0 million in cash, no debt, and working capital of approximately C$26.0 million, with 509.4 million shares outstanding. Eric Zaunscherb serves as President and CEO, following the passing of founder Márcio Fonseca and a subsequent transition period.