Transatlantic Announces Maiden Technical Report and Exploration Target for Monitor Copper Gold Project Three Copper Siderite Vein Exploration Targets Established Phased Development Strategy Targets Bulk Sample Potential
Transatlantic Mining Corp. | Suite 400 | 837 West Hastings Street | Vancouver | Canada
V6C 3N6 T 604-630 7296 | F 604-357 1139| www.transatlanticminingcorp.com
Transatlantic Announces Maiden Technical Report and Exploration
Target for Monitor Copper Gold Project
Three Copper Siderite Vein Exploration Targets Established Phased Development Strategy Targets
Bulk Sample Potential
Vancouver, B.C., December 1, 2025 - Transatlantic Mining Corp. (TSX-V: TCO) (the "Company")
is pleased to announce the completion and filing of its maiden NI 43-101 technical report for
the Monitor Copper Project, an 80% -owned joint venture property located in Shoshone
County, Idaho and Mineral County, Montana.
Highlights:
• Initial NI 43-101 technical report establishes Exploration Targets for three copper siderite
vein systems.
• 2015 drilling by Transatlantic confirmed copper, silver, and gold mineralization with
intercepts up to 1.87% Cu over 0.8m and 71.5 g/t Ag over 0.3m
• Grab samples near Monitor shaft returned 57.7 g/t Ag, 15.4 g/t Au, and >1% Cu
• Combined Exploration Target ranges from 1,200,000 to 2,900,000 tonnes with grades of
1.2-3.5% copper, with further potential for silver and gold credits. Historical mined grades
are well in excess of the Combined Exploration Target.
The potential quantity and grade of the Exploration Target are conceptual in nature. There has been insufficient
exploration to estimate a Mineral Resource and it is uncertain if further exploration will result in the estimation of a
Mineral Resource.
• Project located in the Coeur d'Alene Mining District with road access
• Phased development strategy prioritizes underground drilling with the option of bulk
sampling over the more expensive surface drilling
• St. Lawrence tunnel confirmed structurally sound for 120 meters, enabling a cost-
effective underground exploration platform
"We're extremely pleased with this maiden technical report. Our surface sampling and
drilling has confirmed attractive copper grades with precious metal credits on the property.
This leads into the next phase plan to access into historical underground workings, enabling
more c ost-effective drill sampling and the option for a bulk mine sample," said Bernie
Sostak, CEO of Transatlantic Mining Corp. "Rather than spending heavily on surface
drilling in the mountain terrain, we're leveraging on underground acces s to efficiently
evaluate the deposit through drilling from underground access. This approach de-risks the
project while providing valuable metallurgical data."
Transatlantic Mining Corp. | Suite 400 | 837 West Hastings Street | Vancouver | Canada
V6C 3N6 T 604-630 7296 | F 604-357 1139| www.transatlanticminingcorp.com
Exploration Target
The technical report, prepared by Ethos Geological, represents the Company's first NI 43-101
report for the Monitor Project and details the potential of three exploration targets on the
property: the Monitor, Richmond, and Big Elk copper siderite vein syst ems. These steeply-
dipping fissure veins exhibit characteristics consistent with known copper veins throughout
the Coeur d'Alene Mining District.
The potential quantity and grade of the Exploration Target are conceptual in nature. There has
been insufficient exploration to estimate a Mineral Resource and it is uncertain if further
exploration will result in the estimation of a Mineral Resource.
Table 1: Exploration Target Summary
Vein System Tonnage (tonnes) Copper (%) Silver (g/t) Gold (g/t)
Monitor 550,000 - 1,300,000 1.5 - 2.5 3.5 – 7.5 0.8 – 4.2
Richmond 550,000 - 1,400,000 1.2 - 2.0 4.0 – 8.7 1.0 – 5.5
Big Elk 70,000 - 190,000 2.0 - 3.5 3.0 – 6.5 1.5 – 3.5
The Exploration Target is based on mapped structure lengths from surface workings and
historical reports (Monitor: 488m, Richmond: 1,158m, Big Elk: 305m), documented vein
widths from the 1923 Hershey and Umpleby geological reports, and down-dip extensions to
550 meters vertical depth. Historical mining reached approximately 180 meters depth before
operations ceased in the 1920s. Grade ranges are scaled down from historical production
grades to reflect broader zones of mineralization. Vein widths range from 1.2 to 4.6 meters
based on historical reports. The exploration target assumes discontinuous mineralization
along mapped vein structures, consistent with copper-siderite vein systems elsewhere in the
district.
Project Location and Infrastructure
The Monitor Project is located in the Coeur d'Alene Mining District, where mining has been
conducted continuously since the 1880s to early 1900’s . The great fire of the 1910’s damaged
major infrastructure at that time. The project has road access and is situated in a region with
experienced mining contractors and infrastructure to support exploration and potential
future operations.
Transatlantic Mining Corp. | Suite 400 | 837 West Hastings Street | Vancouver | Canada
V6C 3N6 T 604-630 7296 | F 604-357 1139| www.transatlanticminingcorp.com
Strategic Development Approach
Transatlantic has developed a phased exploration strategy that prioritizes cost -effective
underground evaluation over expensive surface drilling in mountainous terrain. The
Company's 2015 assessment confirmed the St. Lawrence tunnel remains structurally sound
in part to 120 meters, providing direct access to drill the undrilled Monitor vein systems at
depth.
Three-Phase Exploration Program:
Phase 1 - Underground Exploration: Rehabilitation of existing underground workings,
systematic channel sampling and mapping, underground drilling, and an option for the
collection of a 10,000-tonne bulk metallurgical sample. This phase will provide high -quality
geological data while generating material for comprehensive metallurgical testing.
Phase 2 - Property-Scale Surveys: Detailed geological mapping, geophysical surveys
(magnetic and IP/resistivity), and petrophysical analysis to identify additional targets and
refine the geological model.
Phase 3 - Targeted Surface Drilling: Surface drill programs will be designed based on
underground results, focusing on down -plunge extensions and potential stratiform
mineralization in the underlying Revett Formation.
Exploration by Transatlantic (2013-2024)
Table 2: Completed Exploration Activities
Year Activity Laboratory
2013 159 soil samples American Analytical
2013-2014 Geological mapping and
Monitor adit assessment
American Analytical/ALS
Reno
2015 5 diamond drill holes
(Richmond area)
American Analytical
2015 St. Lawrence Tunnel
sampling and assessment
American Analytical
2023 14 HQ drill holes Chris Christofferson Lab
2023 Big Elk rock and channel
sampling
Chris Christofferson Lab
Transatlantic Mining Corp. | Suite 400 | 837 West Hastings Street | Vancouver | Canada
V6C 3N6 T 604-630 7296 | F 604-357 1139| www.transatlanticminingcorp.com
2024 Ground magnetic
geophysical survey
Not applicable
2024 Anvil Tunnel sampling American Analytical
Next Steps
The Company is advancing permitting for underground rehabilitation and underground drill
planning. Management will provide updates as milestones are achieved.
Qualified Person
The technical information in this news release has been reviewed and approved by Zachary
J. Black, SME-RM, Ethos Geological as an Independant Qualified Person as defined under NI
43-101
About Transatlantic Mining Corp.
Transatlantic Mining Corp. (TSX -V: TCO) is a precious and base metals explorer focused on
advancing projects toward production in established mining jurisdictions. The Company
holds an 80% interest in the Monitor Copper Project (Idaho/Montana), 100% of the Golden
Jubilee Gold Project, and rights to the Miller Gold Mine in Montana. The Company
emphasizes cost -effective exploration strategies and partnerships that align with its
development-focused approach.
Cautionary Statement Regarding Forward-Looking Information
This news release contains forward -looking statements within the meaning of applicable
securities legislation. Forward -looking statements relate to future events or future
performance and reflect Company management's expectations or beliefs regarding futur e
events including the potential for mineralization, future exploration programs, timing of
exploration activities, and the ability to obtain financing. These statements are based on
assumptions and involve risks and uncertainties. Actual results may diffe r materially from
those anticipated in these forward -looking statements due to various factors including
changes in economic conditions, regulatory changes, and availability of financing. The
Company undertakes no obligation to update forward -looking state ments except as
required by applicable securities laws.
For further information, please contact:
Transatlantic Mining Corp. | Suite 400 | 837 West Hastings Street | Vancouver | Canada
V6C 3N6 T 604-630 7296 | F 604-357 1139| www.transatlanticminingcorp.com
Bernie Sostak, Chief Executive Officer
Email:[email protected]
Phone: +61 (0) 439 904 044
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in
the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of
this release.