Briefing
The recent discovery of extensions to wide high-grade silver mineralization is delineating a new multimillion-ounce silver-rich hydrothermal system as a result of the application of modern exploration methods. [Learn more](https://grsilvermining.com/san-marcial-area/)  [](https://grsilvermining.com/) Menu - [About](https://grsilvermining.com/about-us/) - [Our Story](https://grsilvermining.com/about-us/#story) - [Management](https://grsilvermining.com/about-us/#management) - [Board of Directors](https://grsilvermining.com/about-us/#board) - [In Memoriam – Our Founder, Márcio Fonseca](https://grsilvermining.com/in-memoriam-marcio-fonseca-tribute/) - [Plomosas Project](https://grsilvermining.com/plomosas-project/) - [Project Overview](https://grsilvermining.com/plomosas-project/) - [San Marcial Area](https://grsilvermining.com/san-marcial-area/) - [Plomosas Mine Area](https://grsilvermining.com/plomosas-mine-area/) - [Investors](https://grsilvermining.com/investors/) - [Stocks Info](https://grsilvermining.com/investors/) - [Presentations and Media](https://grsilvermining.com/investor-downloads/) - [Financial Reports](https://grsilvermining.com/financial-reports/) - [ESTMA Reports](https://grsilvermining.com/estma-reports/) - [Events](https://grsilvermining.com/events/) - [Analyst Coverage](https://grsilvermining.com/investors/#analyst-coverage) - [Why Silver](https://grsilvermining.com/why-silver/) - [News](https://grsilvermining.com/news-releases/) - [Contact](https://grsilvermining.com/contact/) # Plomosas Project Silver Mine Development and Exploration in Southwestern Edge Sierra Madre Occidental, Mexico [View NI 43-101 Reports](https://grsilvermining.com/plomosas-project/#reports)  ## Overview of the Plomosas Project GR Silver Mining’s Plomosas Project is located on the southwestern edge of the Sierra Madre Occidental, a world renowned region for discovery, development and operation of silver mines in Mexico. The Project is in the historic Rosario Mining District, on the border between Durango and Sinaloa states, and covers 78 km² of 100%-owned concessions and permitted historic underground mines. The Plomosas Project integrates the past producing Plomosas Mine and San Juan-La Colorada Areas, and the recently discovered extensive wide and shallow silver mineralization at the San Marcial Area. The existing infrastructure, combined with available permits, offers significant opportunities for future mine and operational developments, resource growth, and supports the Company’s growth in one of Mexico’s richest silver-gold-lead-zinc mining districts.  ## Mineral Resource GR Silver Mining’s NI 43-101 mineral resource estimate for the Plomosas Project, includes multiple areas with predominance of silver in the San Marcial Area and base metals (Pb-Zn) with silver-gold concentrations in the Plomosas Mine Area and the San Juan-La Colorada Area. [Download the Full NI 43-101 Technical Report (2023)](https://grsilvermining.com/wp-content/uploads/2023/05/NI_43-101_Plomosas_Project_May-3_2023.pdf) ## Discover GR Silver Mining’s Project Areas  ## Silver Discovery San Marcial Area A near-surface, silver-dominant mineralization hosted in wide, extensive hydrothermal breccias on the edge of a recently discovered porphyry-style intrusive system. The recent discovery of extensions to wide high-grade silver mineralization is delineating a new multimillion-ounce silver-rich hydrothermal system as a result of the application of modern exploration methods. [Learn more](https://grsilvermining.com/san-marcial-area/)  ## Plomosas Mine Area A permitted development-stage property, including a historic underground mine and operational infrastructure. Recent exploration drilling within the historic mine has identified multiple targets for potential near-term mine development and continued exploration for further resource growth. [Learn more](https://grsilvermining.com/plomosas-mine-area)  409 Granville Street 15th Floor Vancouver, BC, V6C 1T2 +1 236 270 2057 ## Get Company Updates Please enter your name. Please enter a valid email address. [Subscribe](https://grsilvermining.com/plomosas-project/#) Something went wrong. Please check your entries and try again. #### Contact [info@grsilvermining.com](mailto:info@grsilvermining.com)  409 Granville Street 15th Floor Vancouver, BC, V6C 1T2 +1 236-270-2057 ## Get Company Updates \* indicates required Email Address \* First Name #### Contact [info@grsilvermining.com](mailto:info@grsilvermining.com) © 2026 GR Silver Mining Ltd. [Linkedin](https://www.linkedin.com/company/grsilvermining/?viewAsMember=true) [X-twitter](https://x.com/GRSilverMining?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor) [Scroll To Top](https://grsilvermining.com/plomosas-project/#) × Latest news?Projects Overview