Announcement • 19h
Northisle Copper and Gold Inc. Reports Drill Results at Red Dog Deposit
Northisle Copper and Gold Inc. announced the results of drilling at the Red Dog deposit in 2025 and early 2026. A total of 8,112 metres of drilling were completed, including infill, geotechnical, and exploratory drill holes. Drilling at Red Dog has achieved several important objectives. Infill drilling within the western, shallow core of the deposit has confirmed previous drilling results and further validated the presence of shallow, higher-grade mineralization in the deposit. Results from the central portion of the mineral resource were also consistent with the existing resource model and are expected to support increased confidence in the current resource estimate. Perhaps most significantly from an exploration perspective, drilling in the eastern portion of the deposit identified a previously unrecognized high-grade trend at depth. Historic drilling at Red Dog was largely focused on shallow mineralization, and these results highlight the potential for additional areas containing economic-grade mineralization that have not yet been incorporated into existing resource models. As a result of the successful drilling program and the potential to improve ongoing technical work with additional mineralization from Red Dog, the Company is now incorporating the Red Dog drill results in the integrated resource estimate and subsequently into the ongoing pre-feasibility study work. Discussion of Drill Results: A total of 8,112 metres of drilling were completed at the Red Dog Deposit between 2025 and early 2026. The program was designed primarily to support the ongoing PFS through resource conversion, while also advancing metallurgical, geotechnical, and exploration objectives. Of the drilling completed, approximately 5,259 metres were dedicated to infill drilling, aimed at upgrading portions of the current Mineral Resource from the Inferred category to the Indicated category. In addition, 591 metres were drilled in two holes to provide material for metallurgical testing, 515 metres supported geotechnical studies, and approximately 2,338 metres targeted resource expansion and exploration opportunities. A total of 31 holes were completed during the program, with most drilling focused on the eastern portion of the deposit where additional drill density was required to improve resource confidence and support future mine planning. The primary objective of the infill drilling program was to increase confidence in the continuity and distribution of mineralization within the current resource model. Several holes were specifically designed to validate geological interpretations and confirm grade continuity within areas already classified as Indicated resources. Notably, RD26- 29 returned 141.4 metres grading 0.97% Cu Eq. from 3.6 metres, including 76.0 metres grading 1.02% Cu Eq. from 61.0 metres, while RD26-32 intersected 142.5 metres grading 0.67% Cu Eq. from 6.0 metres, including 36.0 metres grading 0.98% Cu Eq. from 19.0 metres. Both holes were drilled within the core of the deposit, where historical drilling density is highest and resources are already classified as Indicated. Core from both holes is also being used as part of the ongoing metallurgical testing program. The results demonstrate excellent continuity of both mineralization and grade distribution, providing additional confidence in the geological interpretation and resource model that underpin the ongoing PFS. Additional drilling was completed in areas of the deposit where wider drill spacing limited resource confidence and geological interpretation. These holes were designed to test continuity between existing intercepts while reducing local gaps within the resource model. Results confirmed the presence of broad and continuous mineralization across these areas, including 47.0 metres grading 0.61% Cu Eq. from 4.5 metres, including 29.5 metres grading 0.80% Cu Eq. from 4.5 metres, in RD26-19; 109.3 metres grading 0.43% Cu Eq. from 36.0 metres, including 20.0 metres grading 0.58% Cu Eq. from 58.0 metres, in RD26-21; 55.1 metres grading 0.33% Cu Eq. from 232.9 metres in RD26-25; and 22.2 metres grading 0.94% Cu Eq. from 16.8 metres and 154.5 metres grading 0.48% Cu Eq. from 49.5 metres, including 24.9 metres grading 0.70% Cu Eq. from 51.1 metres, in RD26-38. Geotechnical holes RDGT25-01 and RDGT25-02 were also positioned to evaluate mineralization continuity while providing important geotechnical information for future engineering studies. These holes returned 51.6 metres grading 0.48% Cu Eq. from 2.4 metres, including 7.6 metres grading 0.84% Cu Eq. from 2.4 metres, in RDGT25-01 and 109.0 metres grading 0.38% Cu Eq. from 52.0 metres, including 10.0 metres grading 0.84% Cu Eq. from 73.0 metres, in RDGT25-02. Together, these results further support the continuity of mineralization throughout the Red Dog resource area and provide additional confidence for future resource modelling and mine planning. Beyond resource conversion, several holes were designed to test the down-dip continuity of mineralization below the current resource envelope in the eastern portion of the deposit, where the recent infill drilling had identified higher-grade mineralization at depth. The identification and follow-up of these higher-grade zones were enhanced by the use of Veracio's Scan technology, which provided near real-time geochemical information and helped guide geological interpretations during the program. Results from RD26-30, RD26-33, RD26-35, RD26-36 and RD26-37 confirmed the presence of a broad and continuous mineralized trend extending below areas targeted by much of the historical drilling. Highlights include 216.0 metres grading 0.67% Cu Eq. from 156.0 metres, including 64.1 metres grading 1.10% Cu Eq. from 288.0 metres, in RD26-30; 126.0 metres grading 0.89% Cu Eq. from 177.0 metres, including 30.0 metres grading 1.65% Cu Eq. from 222.0 metres, in RD26-33; 163.4 metres grading 0.86% Cu Eq. from 165.6 metres, including 18.0 metres grading 1.58% Cu Eq. from 185.0 metres and 33.0 metres grading 1.11% Cu Eq. from 230.0 metres, in RD26-35; 102.3 metres grading 0.49% Cu Eq. from 211.7 metres, including 40.4 metres grading 1.06% Cu Eq. from 317.0 metres and 13.4 metres grading 1.68% Cu Eq. from 344.0 metres, in RD26-36; and 109.0 metres grading 0.57% Cu Eq. from 362.0 metres, including 29.5 metres grading 0.91% Cu Eq. from 392.0 metres, in RD26-37. These results represent one of the most significant geological outcomes of the program. Historical drilling at Red Dog largely focused on the shallower portions of the system, with limited drilling evaluating the continuity of mineralization at depth.
