White Pine Copper Announces Positive Pre-Feasibility Study to Revive One of America's Legendary Copper Districts

Post-Tax NPV_8% of US$1.38 Billion and 23.1% IRR Position White Pine North as a Major New Source of Domestic Copper Supply and Regional Jobs

KEY PFS HIGHLIGHTS

• Post-tax net present value ("NPV") at an 8% discount rate of US$1,376.9 million and internal rate of return ("IRR") of 23.1%; pre-tax NPV_8% of US$1,783.1 million and IRR of 26.2%.
  
  
• Post-tax payback period of 3.4 years from the start of production; and pre-tax payback period of 3.1 years.
  
  
• Initial capital cost of US$905.5 million, representing a post-tax NPV-to-initial-capex ratio of approximately 1.5x.
  
  
• Mineral Resource Estimate of 191.2 million tonnes at 1.62% copper (Indicated: 169.1 Mt at 1.64% Cu and 20.66 g/t Ag; Inferred: 22.1 Mt at 1.51% Cu and 22.66 g/t Ag) Mineral Resources are reported inclusive of Mineral Reserves. Mineral Reserves are derived from the Indicated Mineral Resource after application of the relevant mining and economic factors.
  
  
• Reserve-supported, 26 year mine plan: probable Mineral Reserve of 137.9 million tonnes; steady-state production of  5.4 million ore tonnes per year and more than 45,000 tonnes of payable copper per year. No Inferred Mineral Resources are included in the PFS economic analysis.
  
  
• By-product cash cost of US$1.44/lb copper and all-in sustaining cost of US$2.32/lb copper. White Pine Copper's estimated steady-state AISC, normalized to Wood Mackenzie's 2026 cost curve assumptions, falls within the first quartile of the US subset of the Copper Cost Curve.
  
  
• Brownfield restart, and planned reuse of existing tailings storage infrastructure in Michigan's historic White Pine copper district, which produced approximately 4.5 billion pounds of copper between 1953 and 1995.
  
  
• All major permit applications have been submitted for review by the Michigan Department of Environment, Great Lakes, and Energy ("EGLE").
  
  
• Conventional modified room-and-pillar underground mining and a conventional crush-grind-flotation plant, with copper and silver recoveries of 85.6% and 96.0%, respectively, into a clean, low-penalty concentrate yielding 26.2% copper and 451 g/t silver.
  
  
• WPC targets a Final Investment Decision in the second half of 2027 and commercial production in 2030.

TORONTO and WHITE PINE, Mich., Sept. 22, 2026 /PRNewswire/ -- White Pine Copper LLC ("WPC" or the "Company"), a Michigan-based copper development company wholly owned by Kinterra Copper USA LLC ("Kinterra"), is pleased to announce the results of a Pre-Feasibility Study ("PFS") for its White Pine North Project ("White Pine North" or the "Project") located in Michigan, USA. All dollar amounts are in U.S. dollars unless otherwise stated.

The PFS outlines a technically and economically robust plan to redevelop the historic White Pine copper district as a modern underground mining operation. The plan is supported by an extensive drilling database, a Probable Mineral Reserve, positive metallurgical testwork, and a well-established, state-only permitting framework.

Copper was added to the U.S. Geological Survey's Critical Minerals List for the first time in 2025, as net U.S. import reliance for refined copper has climbed above 40% of consumption. Demand for copper in the United States is expected to grow substantially over the coming decade, driven by electrification, grid modernization and the build-out of domestic manufacturing capacity. White Pine North would rank among the largest new sources of domestically mined copper in the country, and its redevelopment is expected to bring significant employment and economic activity back to a part of Michigan's Upper Peninsula that has experienced sustained economic decline since the historic White Pine Mine closed in 1995.

MANAGEMENT COMMENTARY

"White Pine North is exactly the kind of asset the U.S. copper market needs right now: a large, high-grade deposit in one of the best-understood copper districts in North America, with a clear and capital-efficient path to production. Domestic demand for copper is climbing at the same time domestic supply has been shrinking, and we believe White Pine North can become one of the largest new sources of American-mined copper." said Cheryl Brandon, Co-Founder of Kinterra.

"This PFS is the product of an integrated technical program across resource definition, mine engineering, metallurgy and permitting, and it confirms what this district has always offered: a large, well-understood orebody that modern mining methods can extract efficiently. Just as important, it means jobs and economic activity coming back to a part of Michigan's Upper Peninsula that has waited a long time for it." said Chad Wolahan, Project Director at White Pine Copper LLC.

MINERAL RESOURCE AND RESERVE

The current Mineral Resource Estimate ("MRE") was prepared by Dahrouge Geological Consulting USA Ltd. ("Dahrouge") using a validated drillhole, geological, analytical and density database current as of June 5, 2026, and is reported at a cut-off grade of 0.90% Cu:

• Indicated: 169.1 Mt at 1.64% Cu and 20.66 g/t Ag, containing 2.77 Mt of copper
• Inferred: 22.1 Mt at 1.51% Cu and 22.66 g/t Ag, containing 0.33 Mt of copper
• Total: 191.2 Mt at 1.62% Cu and 20.89 g/t Ag, containing 3.11 Mt of copper

This current MRE supersedes all prior historical estimates for the Project, including the 1995 CRC estimate and the 2019 and 2023 G Mining Services Inc. estimates, none of which should be relied upon.

The Mineral Reserve, effective July 16, 2026, is classified entirely as Probable and totals 137.9 million tonnes at 1.04% Cu and 16.02 g/t Ag, containing approximately 3,171 million pounds of copper and 71.0 million ounces of silver. The Reserve reflects a net smelter return cut-off grade specific to each mining area and an estimated mining dilution of 6% by volume at 100% mining recovery.

PFS RESULTS SHOW ROBUST ECONOMICS

The PFS financial model was developed on a 100%-equity, 100%-ownership basis with no financing costs assumed, applying long-term consensus commodity price assumptions of US$4.97/lb copper and US$53.69/oz silver and an 8% discount rate.

Summary Financial Metrics

• Post-tax NPV (8% discount rate): US$1,376.9 million
• Post-tax IRR: 23.1%
• Post-tax payback period: approximately 3.4 years
• Pre-tax NPV (8% discount rate): US$1,783.1 million
• Pre-tax IRR: 26.2%
• Pre-tax payback period: approximately 3.1 years
• Initial capital cost: US$905.5 million
• Sustaining capital cost: US$863.0 million
• Closure capital cost: US$160.0 million
• Life-of-mine operating cost: US$5,952 million (or US$43.16 per tonne processed)
• By-product cash cost: US$1.44/lb Cu; by-product all-in sustaining cost ("AISC"): US$2.32/lb Cu
• Co-product cash cost: US$2.15/lb CuEq; co-product AISC: US$2.85/lb CuEq
• Mine life: 26 years

Sensitivity analysis indicates the Project's economics are most sensitive to metal price, head grade and recovery, and less sensitive to operating and initial capital costs.

MINE PLAN AND DEVELOPMENT

White Pine North will be mined using a modified room-and-pillar method with no backfill, well suited to the deposit's relatively flat-lying geometry and enabling high equipment utilization and predictable production rates. The mine is designed for steady-state production of 15,000 tonnes per day (5.4 Mt/y), accessed via declines expanding from two to four over the life of mine, with ore delivered to surface via a truck-and-conveyor material handling system. Over the life of mine, total ore mined is estimated at 137.9 Mt at an average grade of 1.04% Cu, containing approximately 3,171 million pounds of copper.

METALLURGY AND PROCESSING

Metallurgical testwork completed between 2024 and 2026 at Intertek's Base Metals Laboratory in Kamloops, BC, supports a conventional processing route comprising crushing, SAG and ball mill grinding, gravity concentration, and flotation. The process is expected to achieve copper and silver recoveries of 85.6% and 96.0%, respectively, producing a clean copper concentrate grading approximately 26.2% Cu and 451 g/t Ag, with low deleterious-element content.

PERMITTING AND LOCATION

White Pine North is located in Ontonagon County in Michigan's Upper Peninsula, within the historic White Pine copper district, which produced approximately 4.5 billion pounds of copper between 1953 and 1995 before operations were suspended. The Project is a brownfield redevelopment that will reuse the site's existing tailings storage infrastructure, reducing its environmental footprint relative to a greenfield development.

All major permit applications have been submitted for regulatory review and fall under the jurisdiction of the Michigan Department of Environment, Great Lakes and Energy pursuant to the Michigan Natural Resources and Environmental Protection Act. The Project requires no federal permits as it involves no federal lands, minerals, or other nexus that would trigger the National Environmental Policy Act. All baseline environmental, archeological and hydrogeological studies have been completed and WPC has engaged with local governments, community groups and Native American communities throughout Project development.

PROJECT SCHEDULE

WPC has commenced a Feasibility Study targeted for completion by mid-2027, with a Final Investment Decision targeted for H2 2027 and commercial production targeted for 2030, reflecting an estimated 30-month construction period following Final Investment Decision.

ABOUT WHITE PINE COPPER LLC

White Pine Copper LLC is a Michigan-based copper development company advancing the White Pine North Project in the Upper Peninsula of Michigan. www.whitepinecu.com.

ABOUT KINTERRA CAPITAL

Kinterra Capital is a private equity firm that invests in the people, ideas, critical materials, and strategic infrastructure necessary to accelerate the development of the modern economy. With nearly 20 years of mining investment experience, Kinterra leverages significant domain specific technical and transactional expertise to source and manage investments that create value for its stakeholders, all while supporting the communities within which we operate through meaningful partnerships. At Kinterra, we focus on creative ideation, rigorous analysis and executing with excellence to make investments that will create sustainable, strong and secure supply chains. For more information about Kinterra Capital, please visit www.kinterracapital.com.

TECHNICAL CONSULTANTS

The scientific and technical information in this press release relating to the MRE is based on, and fairly represents, information prepared under the supervision of Paul Richardson, M.Sc., RM-SME, an employee of Dahrouge, which is independent of the Company. Mr. Richardson is a Qualified Person as defined by National Instrument 43-101 and has reviewed and approved the mineral resource information contained in this press release. The technical data, engineering designs, and cost estimates supporting the Pre-Feasibility Study were prepared by experienced, independent consulting firms under the oversight of the Company and relevant subject matter experts. The consulting firms and their respective areas of contribution to the Pre-Feasibility Study are outlined below.

• Ausenco Engineering Canada ULC: Process flowsheet, process plant and surface ancillary infrastructure design; overall cost estimates, financial model and PFS compilation.
• Dahrouge Geological Consulting USA Ltd.: Geology modeling and MRE.
• Foth Infrastructure & Environment, LLC: Environmental studies and permitting, water balance and water management.
• Stantec Consulting Services Inc.: Underground mine design and engineering, including the mine planning and modifying factors used to support declaration of the Probable Mineral Reserve.
• WSP USA Inc.: Underground geotechnical programs and design criteria.
• Tetra Tech, Inc.: Tailings disposal facilities design and hydrology modeling.
• SRK Consulting (U.S.), Inc.: Geochemical programs.
• Paterson & Cooke USA, Ltd.: Tailings thickening and tailings pumping systems.

CAUTIONARY NOTE REGARDING THE PRE-FEASIBILITY STUDY

The PFS is preliminary in nature. Mineral Reserves have been estimated in accordance with the CIM Definition Standards for Mineral Resources and Mineral Reserves and are supported entirely by Indicated Mineral Resources; no Inferred Mineral Resources have been included in the Mineral Reserve estimate or in the PFS economic analysis. There is no certainty that the PFS results will be realized.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This press release contains certain forward-looking statements relating to WPC and the White Pine North Project, including, but not limited to, statements regarding mineral resources and reserves, estimated grades and recoveries, anticipated production rates, development plans, project economics, capital and operating costs, metal price assumptions, permitting and permitting timelines, the timing of the Feasibility Study, Final Investment Decision and commercial production, construction timelines, and market conditions. These statements are based on current expectations, estimates, projections, and assumptions that are subject to a range of known and unknown risks and uncertainties, many of which are beyond the control of WPC and Kinterra. Factors that could cause actual results to differ materially from those anticipated include, without limitation: changes in commodity prices; delays or difficulties in obtaining necessary permits and approvals; unforeseen engineering, construction, or geotechnical challenges; changes in capital or operating cost estimates; fluctuations in currency exchange rates; changes in applicable laws, regulations, or government policies; labor availability and relations; and general economic, market, or business conditions. Actual results or events may differ materially from those expressed or implied by such forward-looking statements. Except as required by applicable law, WPC and Kinterra undertake no obligation to update or revise any forward-looking statements.

Media Contacts: Kinterra Capital, Mairi MacEachern, [email protected], [email protected]; White Pine Copper, Meagen Morrison, [email protected]

SOURCE Kinterra Capital