Sierra Madre increases M&I Silver-Equivalent resources at La Guitarra by 373% to 27.2 million ounces, inferred Silver- Equivalent resource increased 204%to 20.2 million ounces
Sierra Madre Gold and Silver Ltd. (TSXV: SM, OTCQX: SMDRF) ("Sierra Madre" or the "Company" - https://www.commodity-tv.…