Sterling Mining Company founded Sterling Mining de Mexico SA in 2004. The initial project was the Baroness Project which entailed building seventeen Vats using a thiosulphate process to process tailings and ore. The project began production in 2005. The Company steadily expanded acquiring new prospects and projects,, By 2007 the Company employed forty five people in Mexico. The late Martin Sutti was the General Manager , and Gilberto Zapata as Chief Financial Officer.
Martin Sutti, General Manager
Ray De Motte- President- Holding First Silver Dore Bar from Baroness Project
Sterling began operations in Mexico, with the Baroness Silver Project in 2004. It was the first environmentally-safe thiosulphate project in  Zacatecas. Sterling’s President Ray De Motte and in Mexico General Manager the late Martin Sutti, spearheaded development of properties in  Mexico. The Baroness reached solid profitable commercial production, and by 2006 surface material from the San Acacio project was also being  processed.
By 2008 operations in the Zacatecas Silver District were providing quarterly cash flow to Sterling Mining Company helping to support Sterling’s activities in the Coeur d’Alene Mining District ; negotiations began with major Mexican mining company to expand Sterling’s land package for a proposed joint-venture; and Sterling Mining employees in Mexico were preparing an advanced 2009 exploration and development plan to increase resources at the San Acacio mine . In 2008 after change in management at Sterling Mining Company from June 2008 on Sterling Mining Mexico was in disputes with new management at Sterling Mining Company. All plans for expanding production , resources, and joint-ventures ended.
Major Mining Projects and Mining Concessions
Sterling Mining’s Mexico portfolio included several historically significant and high‑potential silver properties:
Baroness Silver Project
San Acacio
A historic silver district with long‑standing production history and strong exploration potential.
Initiatial production processed at Baroness facility and nearby Arca mill
Defiance Silver is exploring the project today..
El Morro
A concession with favorable geological structures and vein systems typical of the Zacatecas silver belt..
Vetas Negras
Known for narrow, high‑grade vein systems characteristic of the region.
Tesorito–Tabasquena
A multi‑zone concession with exploration targets aligned with regional mineralization trends. Prior operator estimate of million 15 milli ounces of silver resource
El Griego, La Chapis, Cuatro Ciénegas
Additional concessions acquired during Sterling’s expansion phase, each offering unique geological features and long‑term development potential.
Technical Innovation: Thiosulfate Silver Processing
Sterling Mining was an early adopter of thiosulfate‑based silver recovery, a process designed to:
The prolific Zacatecas Silver Mining district was the focus of Sterling Mining in Mexico
The Zacatecas Silver District is one of the most prolific silver mining districts in the world with over 600 million ounces of silver produced since the 1500s