GR Silver Mining Ltd. announced an independent, updated Mineral Resource Estimate (the ‘Resource Estimate') in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects (‘NI 43-101') for the Company's wholly-owned Plomosas Project in Sinaloa, Mexico. The Resource Estimate was completed by ARSENEAU Consulting Services Inc, (‘ACS') of Vancouver, British Columbia, Canad and integrates resources for the San Marcial, Plomosas Mine and San Juan-La Colorada Areas within the Plomosas Project. Highlights of the Resource Estimate including comparison to the previous mineral resource estimates1 are: 108% increase in indicated mineral resources from 46 Moz to 97 Moz silver equivalent2 (‘AgEq') 72% increase in indicated mineral resources from 32 Moz to 55 Moz Ag 61% increase in inferred mineral resources from 33 Moz to 53 Moz AgEq 20% increase in inferred mineral resources from 18 Moz to 22 Moz Ag 44% increase in average indicated mineral resource grade from 143 to 206 g/t AgEq 65% increase in average inferred mineral resource grade from 112 to 185 g/t AgEq San Marcial Area 80% increase in indicated mineral resources from 36 Moz to 65 Moz AgEq 65% increase in inferred mineral resources from 12 Moz to 20 Moz AgEq Indicated mineral resources of 9.7 Mt at 209 g/t AgEq (148 g/t Ag) Inferred mineral resources of 3.0 Mt at 200 g/t AgEq (145 g/t Ag) 71% of the value of the San Marcial Resource Estimate is comprised of silver 91% of the 65 Moz AgEq San Marcial indicated resources are potentially amenable to open pit extraction True width of the modelled San Marcial mineralization averages 22 metres, while the SE Area discovery averages 53 metres in thickness, supporting potential for low-cost bulk mineable open pit and/or underground mining methods Plomosas Mine Area 2022 infill drilling resulted in an increase of 137% in the indicated mineral resource tonnage 260% increase in indicated mineral resources from 9 Moz to 31 Moz AgEq Ag and AgEq grade increased by 30% and 52%, respectively, in indicated mineral resources in relation to the previous resource estimate Ag ounces represent 20% of total indicated mineral resources at the Plomosas Mine Area Ag ounces represent 26% of total inferred mineral resources at the Plomosas Mine Area True width of modelled mineralization at the Plomosas Mine Area averages 20 metres, supporting potential for low-cost bulk mineable open pit and/or underground mining methods 46% of the value of the Resource Estimate at the Plomosas Mine Area is comprised of precious metals The San Marcial Area, including the SE Area discovery, with indicated mineral resources of 9.7 Mt at 209 g/t AgEq (148 g/t Ag) and inferred mineral resources of 3.0 Mt at 200 g/t AgEq (145 g/t Ag) represents approximately 78% of Ag contained in the total Resource Estimate.

Shallow infill drilling during 2022 in the 2019 resource area has enhanced the definition of high-grade silver zones close to surface within the San Marcial mineral resource defining the potential for an open pit amenable portion of the San Marcial Area resource estimate. Infill drilling in the previous resource area of the Plomosas Mine during 2022 has enhanced the definition of silver grades particularly closer to the surface, at shallow levels of the historic underground mine, where the Company achieved better delineation of high-grade Ag zones. At the lower levels of the historic underground mine, the Pb-Zn mineralization continues to provide a strong contribution to the Resource Estimate.

Overall, the average silver grades for indicated and inferred resources in the Resource Estimate for the Plomosas Mine Area are slightly higher than the 2021 resource estimate. The Resource Estimate for the San Juan-La Colorada Area consists primarily of an update in the geological model and limited drilling to integrate newly interpreted structural controls into the resource estimation. A slight increase in the gold grades can be observed, particularly at La Colorada, resulting from a more detailed modelling, when compared with the previous resource estimate.