Vancouver, British Columbia -- September 22, 2026 - Casa Minerals Inc. (TSXV: CASA) (OTCQB: CASXF) (FSE: 0CM) (the "Company" or "Casa") is pleased to announce that diamond drilling has commenced at its Arsenault copper-gold-silver volcanogenic massive sulphide ("VMS") project (the "Property" or "Arsenault"), located in the Jennings River area of northern British Columbia, approximately 130 kilometres east-northeast of Atlin, BC, near the Yukon border. This is the first drilling ever carried out by Casa at Arsenault and one of the first modern drill tests of the Arsenault VMS system.

First Hole of the Inaugural Program

The first hole of the program is collared on IP survey Line 15E at UTM coordinates Easting 347,110 mE and Northing 6,632,206 mN (UTM Zone 9N). The hole is oriented at an azimuth of 045° (N45°E) with a dip of -85° - a near-vertical attitude selected to intersect, at relatively shallow depth, the sub-vertical chargeability and resistivity feature defined by the Company's 2025 ground induced polarization ("IP") survey. The collar is positioned directly over a first-priority IP anomaly characterized by strong chargeability and low-to-moderate resistivity, coincident with an interpreted fault/contact - the geophysical signature the Company considers most prospective for massive sulphide mineralization on the Property (Figure 1).