Technical Reports
Mineral Resource Estimate · May 27, 2025 · effective date December 31, 2024
The Rainbow Block hosts an inferred mineral resource only. The Company has no mineral reserves, and economic viability has not been demonstrated. See Important Notices.
What this report means
What is a mineral resource?
A concentration of minerals with reasonable prospects for eventual economic extraction. It is a geological estimate, not a bankable, mineable quantity.
What does "inferred" mean?
Inferred is the lowest of the three confidence categories. It is based on limited drilling and sampling; geological continuity is implied but not yet confirmed, so it cannot be used as the basis for economic studies until upgraded.
Why are there no reserves yet?
Mineral reserves require a positive economic study (at least a pre-feasibility study) plus modifying factors: metallurgy, mining method, permitting and costs. That work has not been completed, so the project has resources, not reserves.
What do the assumptions imply?
The silver-equivalent figure uses set metal prices (Au $2,500/oz, Ag $25/oz, Zn $1.31/lb, Pb $0.90/lb), a 4 oz/t AgEq cut-off and 90% metallurgical recovery. Different prices or recoveries would change the estimate.
What could upgrade the resource?
Infill and underground drilling to raise confidence toward indicated/measured; modern metallurgical testing; and evaluation of narrow veins Anaconda historically did not map (under 7 ft) and mineralization at depth.
What still needs to be proven?
Modern metallurgical recovery, geotechnical and mining-method work, permitting for development, and economic viability through a future study.
What changes the valuation next?
Drill results, a resource-classification upgrade, metallurgical results, permitting progress, and ultimately a preliminary economic assessment.
Silver Bow Mining Corp. has released an inferred Mineral Resource estimate on its flagship Rainbow Block property. The inferred Mineral Resource estimate is contained within a Technical Report Summary prepared in accordance with the requirements of Subpart 1300 of Regulation S-K (“S-K 1300”) titled ‘Technical Report Summary: Rainbow Block, Butte Mining District, Silver Bow County, Montana, USA’ and National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”) Technical Report titled ‘Technical Report on the Rainbow Block Property, Butte Mining District, Silver Bow County, Montana, USA’ with an effective date of December 31, 2024, prepared by Jacob Anderson, CPG, MAusIMM of Dahrouge Geological Consulting.
| Category | Vein Material — Tons (M) | AgEq oz (M) | AgEq oz/t |
|---|---|---|---|
| Inferred | 11.48 | 170.0 | 14.8 |
| Total | 11.48 | 170.0 | 14.8 |
| Category | Vein Material — Tonnes (M) | AgEq oz (M) | AgEq g/tonne |
|---|---|---|---|
| Inferred | 10.4 | 170.0 | 507.4 |
| Total | 10.4 | 170.0 | 507.4 |
| Metal | Unit | Price (USD) | Recovery |
|---|---|---|---|
| Gold (Au) | oz | $2,500 | 90% |
| Silver (Ag) | oz | $25.00 | 90% |
| Zinc (Zn) | lb | $1.31 | 90% |
| Lead (Pb) | lb | $0.90 | 90% |
Key Highlights
- 170 million silver equivalent ounces inferred resource at 14.8 oz/ton (or 4.28 oz/ton Ag, 0.05 oz/ton Au, 1.25% Pb, and 4.59% Zn) within 11.48 million tons of vein material conducted under S-K 1300 and NI 43-101 standards
- Ownership of 878 acres of patented mineral rights on the Rainbow Block, in the Butte Mining District
- 42 veins above modeled water table, approximately 1,000 ft of below surface
- Established infrastructure with exploration permit in place
- Over 10,000 miles of historical workings demonstrate extraction of ore in the Butte Mining District has had reasonable success where operations had sufficient grade, quantity, and geological understanding
Average Grade by Metal and Contained Metal in the AgEq Inferred Mineral Resource Estimate
Average individual metal grades and contained metal for the individual metals included in the AgEq calculation within the AgEq inferred Mineral Resource estimate for the Rainbow Block were calculated using a cut-off grade of 4 oz/t AgEq and 90% metallurgical recovery.
| Tons (M) | Ag Ounces | Ag oz/ton | Au Ounces | Au oz/ton | Pb lbs (M) | Pb % | Zn lbs (M) | Zn % |
|---|---|---|---|---|---|---|---|---|
| 11.48 | 49,155,194 | 4.28 | 553,549 | 0.05 | 287 | 1.25 | 1,053 | 4.59 |
| Tonnes (M) | Ag Ounces | Ag g/tonne | Au Ounces | Au g/tonne | Pb Tonnes (M) | Pb % | Zn Tonnes (M) | Zn % |
|---|---|---|---|---|---|---|---|---|
| 10.4 | 49,155,194 | 145.7 | 553,549 | 1.7 | 0.13 | 1.25 | 0.47 | 4.59 |
The inferred Mineral Resource estimate was prepared by Dahrouge Geological Consulting from a database of 273 historical drill holes, 8 recent diamond drill holes, and over 15,000 Anaconda Company underground channel samples. The assessment utilized wireframe boundaries to domain the combined drill-hole and channel sampling database into 42 veins.
Based on this assessment, the Company has established an inferred Mineral Resource estimate of approximately 170 million silver equivalent ounces. The Company intends to advance this resource through upgraded classification studies, modern metallurgical testing, and evaluation for narrow-vein underground mining using the latest backfill technologies to optimize extraction efficiency and environmental performance.
See Important Notices for technical disclosure information regarding historical estimates and the current inferred Mineral Resource estimate.
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