La Guitarra

The La Guitarra mine, located 130 km southwest of Mexico City in the historic Temascaltepec district, is a fully permitted underground silver-gold operation owned by Sierra Madre. Acquired from First Majestic in 2023 for US$35 million, the mine features a 500 tpd flotation mill and extensive infrastructure. Commercial production began on January 1, 2025 following a ramp-up in 2024, with Sierra Madre reporting ongoing production and concentrate sales from the operation. The company has also outlined a twophase expansion plan to increase processing capacity to 750 to 800 tpd by Q2 2026, followed by a further expansion to 1,200 to 1,500 tpd by Q3 2027.

Historically producing 1 to 1.5 Moz AgEq per year, La Guitarra hosts significant exploration upside with over 100 known veins. A 2023 resource update outlined 27.2 Moz AgEq in Measured and Indicated Resources and 20.2 Moz AgEq in Inferred Resources. Sierra Madre started a 20,000+ meter drill program in the second half of 2025 on the East District concessions while continuing expansion and exploration work across the broader district.

Metalla received 131 GEOs from La Guitarra in 2025. Metalla holds a 2% NSR royalty on La Guitarra, subject to a 1% buyback for US$2 million.