Sierra Madre Announces Nazareno Silver and Gold Mine Preparing for Production

Vancouver, British Columbia--(Newsfile Corp. - September 30, 2025) - Sierra Madre Gold and Silver Ltd. (TSXV: SM) (OTCQX: SMDRF) ("Sierra Madre" or the "Company") is pleased to announce that underground development has started at the Nazareno silver and gold mine within the La Guitarra silver-gold complex in Estado de Mexico, Mexico. To date, over 700 tonnes of mineralized material have been delivered to the Guitarra processing plant from Nazareno. This material was not included in the Mineral Resource Estimate.

Alex Langer, Chief Executive Officer, commented, "We are excited to be opening a third mining center at La Guitarra, less than a year after achieving commercial production at our first mine within the complex. We expect Nazareno to be a significant contributor to silver and gold production as we advance our fully funded plant expansion plans, which would more than double capacity from current 500 t/d levels by Q3 2027."

Nazareno Mapping by Sierra Madre

Development blasting at Nazareno, followed by detailed mapping, has revealed that several silver and gold-bearing veins merge in this area to form a zone up to 8 meters wide. Figure 1 below shows a northwest looking view of the workings with new mapping completed by Sierra Madre. The Access Drive and the 150 level are separated by 30 vertical meters.

Figure 1: Nazareno Section Looking NW: Geologic Features Mapped by Workings

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/10436/268453_19c1c0def4461a8e_00 ...

Development Reconciliation to Resource Model

In a reconciliation of the silver-gold material produced from development blasting to the surrounding resource blocks contained in the 2023 Nazareno resource model, the production silver grades are 40% higher, and gold grades are 30% higher, based a comparison of the grades delivered to the mill vs. the 2023 resource block model for the surrounding area. Table 1 below shows the 2023 resource estimate for Nazareno.

Table 1: Nazareno 2023 Mineral Resource Estimate, David G. Thomas P. Geo (Effective Date: October 24, 2023)

Class	Tonnes	AgEq (g/t)	Ag (g/t)	Au (g/t)	AgEq Ozs
Indicated	309,877	257.3	214.9	0.55	2,564,000
Inferred	753,784	251.5	229.2	0.29	6,096,000