Red Mountain Mining (ASX: RMX) reported strong exploration momentum across its US and Australian portfolio during the December 2025 quarter, led by expanded land positions and multiple new antimony targets. The company completed detailed geological mapping across its Utah antimony project, confirming host rocks and alteration styles consistent with high-grade antimony mineralisation seen at the nearby Antimony Canyon district. Red Mountain expanded the project footprint to 106 claims after securing an additional 19 claims covering the southern extension of these key fault corridors. Idaho Antimony Projects Build Strategic ScaleAt the Yellow Pine antimony project in Idaho, Red Mountain increased its landholding by 75% to 426 hectares after recognising potential for undiscovered gold and antimony mineralisation during early reconnaissance work. With multiple antimony projects now advanced to the target-definition stage, Red Mountain plans further surface work, geophysics and initial drilling during the first half of 2026.