Sierra Madre Gold and Silver Ltd. announced that SEMARNAT, the federal Mexican regulatory agency in charge of environmental permitting, has approved modifications to the existing operating permit for the Guitarra Mine and Mill complex, located in the State of Mexico, Mexico. These modifications will allow for: Dry Stack Tailings Deposition at the Active Tailings Facility Site, TSF 1-3, Construction of a Tailings Filter Plant Adjacent to the Existing Mill, Paste Backfill Using Tailings in the Guitarra Underground Mine, 58 surface drilling pad locations. Regulatory approval for dry stack tailings deposition is a significant milestone for Sierra Madre as it moves forward with the possible mine restart at Guitarra.

This approval allows the Company to transition from conventional tailings deposition to a more modern system and delays the near-term capital expense of building the fully permitted 5.8 million tonne TSF 4. The use of dry stack deposition will result in more process water being recycled and will allow more tonnes of tailings to be deposited within the existing footprint of TSF 1-3. Dry stacked tailings are the more environmentally responsible alternative and provide a higher level of safety and security long term. TSF 1-3 has two conventional tailings deposition sites with a remaining capacity of 230,000 tonnes which the company plans to use in initial startup operations. Construction on one site began in April and is scheduled for completion before the onset of the rainy season in June.

The dam, or bordo, is being built in 30 cm compacted lifts. The inner bordo face and bottom will be covered with a high-strength HDPE liner, as per accepted industry practices. At the processing plant's operating capacity of 500 tonnes per day, the two expansions will be sufficient for a minimum 15 months of operations, providing the Company with time to complete the design and construction of a combined dry stack and paste backfill tailings disposal system.

High-level studies conducted by Stantec Consulting International LLC and Ingenieria y Construcción de Presas S.A. de C.V. suggest that TSF 1-3 may potentially have a dry stack tailings capacity of at least 500,000 tonnes. The Company has decided to conduct additional geotechnical drilling and studies during the upcoming rainy season to obtain additional high-water saturation data before proceeding with the final layout and design work. This will enable the Company to make better-informed operational decisions.

The approval for the use of tailings for paste backfill is another significant development both operationally and from an environmental perspective. Instead of depositing tailings in TSF 1-3, a portion of the process water is removed from the tail product of the plant, then pumped as a slurry to mined-out areas, mixed with cement, and used to fill open voids. This enhances overall mine stability, increases process water recycling, reduces the potential of acid generation in the surface environment and saves space in TSF 1-3. The Company initially plans to utilize paste fill in stopes below the main San Rafael haulage level, 10 meters above the processing plant.

This relatively small elevational difference minimizes initial pumping requirements, potentially reducing initial capital and operating costs. 58 surface drill pad sites were approved for testing the Progresso, Perdida Guitarra, and 350 veins near existing Guitarra mine workings and the Las Palms/Inca and Santa Teresa vein systems north of the existing underground workings. The Las Palms/Inca and Santa Teresa vein systems have never been drill-tested and have a combined strike length at surface in excess of 9 km.

All vein systems contain historic mine workings, and multiple surface samples have returned economically interesting silver and gold values.