Drilling & Exploration
Historical and current drill results · 2026 surface program · underground exploration plan
Assay intervals below are vein intercepts as drilled, not true thickness. Results outside the current inferred Mineral Resource Estimate do not form part of the resource. See Important Notices.
2026 Surface Drilling
Active 25,000-foot surface drill program on the Rainbow Block, targeting expansion of the existing inferred Mineral Resource Estimate. Multi-element assays will better define the concentration of U.S. Critical Minerals.
- 7.0 feet grading 16.1 opt silver in the Silver City Vein
- 11.9 feet of 11.23% zinc with 9.38 ppm indium in the Badger Vein
Intersected mineralization from 640 to 1,980 feet beyond the current inferred resource boundary along strike.
- 3.8 feet of 7.9% zinc and 86.7 ppm indium in the Badger Vein
Extended mineralization from 930 to 2,270 feet beyond the current inferred resource boundary.
Multiple veins intercepted in both holes lie entirely outside the current inferred Mineral Resource Estimate footprint, and in some cases represent previously unknown veins. Results demonstrate strong precious and base metal enrichment; indium potentially adds technical and economic upside.
Source: Silver Bow Mining Corp. press release dated June 22, 2026. See the release for QA/QC procedures and complete assay tables.
Drilling Highlights
Assay highlights across 10 veins from drill holes by Anaconda, New Butte Mining, and Silver Bow Mining Corp. Data come from reverse-circulation and surface and underground diamond core holes, from a database of surface and underground drilling and over 15,000 Anaconda channel samples overseen by independent Qualified Persons.
| Vein intercept | Hole ID | Dip | Azimuth | From (ft) | To (ft) | Interval (ft)* | AgEq (opt)** | Au (opt) | Ag (opt) | Pb (%) | Zn (%) | Mn (%)*** | Cu (%)*** |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainbow-Alice | BJS21-03 | -60 | 160 | 410.5 | 454.0 | 43.5 | 8.9 | 0.014 | 3.60 | 1.7 | 2.6 | 3.8 | 0.1 |
| including | 445.5 | 446.9 | 1.4 | 38.8 | 0.045 | 13.27 | 10.1 | 13.1 | 5.5 | 0.2 | |||
| Rainbow-Alice | BJS21-23 | -45 | 0 | 419.0 | 465.0 | 46.0 | 9.7 | 0.010 | 2.32 | 2.1 | 4.6 | 2.8 | 0.1 |
| including | 425.0 | 430.0 | 5.0 | 19.1 | 0.015 | 5.51 | 3.4 | 9.2 | 3.9 | 0.1 | |||
| Badger-State | BJS21-24 | -60 | 180 | 225.5 | 238.5 | 13.0 | 6.9 | 0.012 | 4.34 | 0.2 | 1.2 | 2.3 | 0.0 |
| including | 230.0 | 235.0 | 5.0 | 10.3 | 0.019 | 7.20 | 0.3 | 0.9 | 3.0 | 0.0 | |||
| Rainbow-Alice | BJS21-25 | -45 | 350 | 19.0 | 33.5 | 14.5 | 10.4 | 0.027 | 5.31 | 1.1 | 1.5 | 8.6 | 0.2 |
| Rainbow-Alice | BJS21-26 | -60 | 180 | 97.0 | 110.0 | 13.0 | 12.0 | 0.019 | 3.15 | 3.3 | 4.4 | 6.4 | 0.2 |
| including | 97.0 | 102.0 | 5.0 | 13.5 | 0.009 | 2.10 | 5.5 | 6.2 | 3.3 | 0.2 | |||
| Lexington-Missoula | BJS21-31 | -50 | 325 | 309.5 | 316.6 | 7.1 | 12.7 | 0.022 | 4.31 | 0.8 | 5.4 | 0.1 | 1.0 |
| including | 311.5 | 315.2 | 3.7 | 23.7 | 0.041 | 8.20 | 1.3 | 10.0 | 0.0 | 1.8 | |||
| Edith May | 391-301 | -90 | 0 | 40 | 50 | 10.0 | 58.3 | 0.149 | 42.8 | 0.3 | 0.37 | — | — |
| Goldsmith Splay | 3C_DDHSE | -39 | 156 | 68 | 71 | 3.0 | 22.0 | 0.046 | 17.2 | 0.2 | 0.05 | 0.3 | — |
| Rainbow-Alice | 3C_DDHSE | -39 | 156 | 176 | 182.5 | 6.5 | 53.1 | 0.192 | 27.3 | 2.7 | 4.4 | 7.0 | — |
| Skyrme | NBM88-12 | -45 | 200 | 344 | 347 | 3.0 | 33.0 | 0.043 | 19.2 | 1.9 | 7.8 | — | 0.1 |
| Chief Joseph | NBM88-3 | -60 | 200 | 593 | 596 | 3.0 | 39.3 | 0.123 | 16.8 | 3.1 | 7.6 | — | 0.2 |
| Chief Joseph | NBM88-4C | -55 | 175 | 786 | 791 | 5.0 | 60.2 | 0.233 | 24.8 | 2.1 | 10.1 | — | 0.1 |
| Chief Joseph | NBM88-7 | -45 | 187 | 345 | 349 | 4.0 | 83.4 | 0.222 | 50.6 | 4.1 | 7.3 | — | — |
| Lexington-Missoula | NBM88-U19 | -12 | 0 | 174 | 185 | 11.0 | 223.8 | 1.308 | 82.9 | 2.4 | 8.0 | — | 1.3 |
| High Ore | NBM89-1 | -30 | 354 | 256.1 | 259.4 | 3.3 | 57.9 | 0.287 | 22.2 | 3.2 | 4.5 | — | — |
| Wild Bill | NBM89-2 | -35 | 355 | 268.5 | 274.7 | 6.2 | 45.7 | 0.164 | 8.6 | 5.2 | 16.2 | — | — |
| State | NBM90-U3 | 0.4 | 4 | 305 | 313 | 8.0 | 39.5 | 0.090 | 13.1 | 2.5 | 14.9 | — | — |
* Interval represents vein intercept as drilled — NOT true thickness.
** AgEq formula values (metal price in USD, recovery %): Au = $2,500 100%, Ag = $25.00 100%, Pb = $0.90 100%, Zn = $1.31 100%.
*** Mn and Cu are not included in the AgEq value.
Source: Company materials generated from the Technical Report Summary, Rainbow Block, Butte Mining District, Silver Bow County, Montana, USA, prepared by Dahrouge Geological Consulting, effective date of December 31, 2024.
Underground Exploration Program
Chief Joseph Decline: rehabilitation underway
- Chief Joseph portal, at the eastern end of the Rainbow Block on the historic Badger State mine property. The underground contractor mobilized in May 2026 and rehabilitation is underway.
- Decline dimensions of 12 ft × 14 ft, designed for mechanized equipment and long-term ventilation requirements.
- Planned to connect with the 400-foot level, and designed to eventually reach the 800-foot level, planned to be the lowest level above the water table.
- Provides underground drill platforms for resource definition and expansion; access to veins for evaluation and mining of a 10,000-ton bulk sample to test metallurgical performance and dense media separation (DMS) potential.
Planned: next 24 months
- Underground drilling planned to commence in Q4 2026. Steeply dipping veins are most efficiently defined from underground drill stations.
- Drill bays to enable definition drilling and testing of exploration targets adjacent to the current inferred Mineral Resource Estimate.
- Lexington Tunnel rehabilitation.
- Construction of the Rainbow Decline and the Goldsmith Decline.
- Infrastructure designed for reuse in future potential production scenarios.
This section contains forward-looking statements regarding planned exploration and development activities, which are subject to risks and uncertainties including permitting, financing, and operational factors. Actual results may differ materially. See Important Notices and the risk factors in the Company’s SEC filings.