Silver Bow Mining on June 22, 2026 reported assay results from the first two diamond drill holes totalling 2,065 ft. (762m) of its 25,000-foot (7,620m) surface diamond drilling program at the Rainbow Block Project in Butte, Montana. Drill hole SBM26-01 intersected mineralization from 640 ft. to 1,980 ft. (195m to 604m) beyond the current inferred resource boundary along strike, while SBM26-02 extended from 930ft. to 2,270ft. (283m to 692m) beyond the boundary.
Beyond the Headline
Silver Bow Mining on June 22, 2026 reported assay results from the first two diamond drill holes totalling 2,065 ft. (762m) of its 25,000-foot (7,620m) surface diamond drilling program at the Rainbow Block Project in Butte, Montana. Drill hole SBM26-01 intersected mineralization from 640 ft. to 1,980 ft. (195m to 604m) beyond the current inferred resource boundary along strike, while SBM26-02 extended from 930ft. to 2,270ft. (283m to 692m) beyond the boundary.
Multiple veins intercepted in both holes lie entirely outside the current inferred Mineral Resource Estimate footprint, and in some cases, represent new veins which were previously unknown. Results reported as shown in Table 1 are divided into precious metal enriched intervals and base metal enriched intervals by vein name along with the distance from the 2025 inferred mineral resource estimate (MRE) of 11.48 tons ( tonnes) at 4.28 oz/t Ag ( g/t Ag), 0.05 oz/ton Au ( g/t Au), 1.25%Pb and 4.59% Zn. Figure 1 shows a 3D model of the interpreted veins systems with location of the two drill holes. Figures 2 and 3 are cross sections of Holes SBM-26-01 and SBM-26-02 showing interpreted veins and intersections. Figure 4 is a longitudinal section of the Badger Vein showing locations of the drill hole intercepts relative to the MRE and existing underground workings.
Notable intercepts highlighted in the press release include 7.0 ft (2.2m) grading 16.1 oz/t Ag (552 g/t Ag) in the Silver City Vein, 11.9 ft (3.7m) of 11.23% zinc with 9.38 ppm indium in the Badger Vein, and 3.8 ft (1.1m) of 7.9% Zn and 86.7 ppm indium also in the Badger Vein. True widths are estimated at 53-73% of the reported interval widths in SBM26-01 and 60-80% of the reported interval widths in SBM26-02.
This is a very positive start to the summer drilling program. These early intercepts not only confirm the lateral extension of multiple modeled veins well beyond the current inferred MRE but also identify previously unmodeled veins. As a result of this strong start, the Company has mobilized an additional two diamond drill rigs to accelerate the resource expansion program.
Table 1
Source: Silver Bow Mining
Metric unit drill intercept summary showing the distance along strike to the nearest inferred Mineral Resource Estimate boundary on each vein. N/A indicates a previously unknown vein; g/t = grams per metric tonne; ppm = parts per million.
Figure 1
Source: Silver Bow Mining
3D model of veins systems showing locations of drill holes SBM-26-01 and SBM-26-02 (Silver Bow press release June 22, 2026).
Figure 2
Source: Silver Bow Mining
Cross Section of Hole SBM26-01 showing interpreted vein systems and intersections in these veins. Results are given in Table 1 above.
Figure 3
Source: Silver Bow Mining
Cross Section of Hole SBM26-02 showing interpreted vein systems and intersections in these veins. Results are given in Table 1 above.
Figure 4
Source: Silver Bow Mining
Longitudinal section of the Badger Vein showing locations of the drill hole intercepts relative to the MRE and existing underground workings.
