Highland Copper Drives Optimization Efforts at Copperwood Project, Targeting Q1 2027 Feasibility Update Amidst Robust Copper Market

HIGHLAND, MI – June 4, 2026 – Highland Copper Company Inc. is undertaking a comprehensive series of detailed engineering and optimization studies at its wholly-owned Copperwood project located in Michigan, US. The primary objective of these intensive efforts is to publish an updated feasibility study in the first quarter of 2027 (Q1 2027). This planned update is a critical step, designed not only to refine the project's technical parameters but also to buttress its financial planning and attractiveness for potential investors, particularly as the demand for domestic copper resources continues to intensify.

The Copperwood project holds significant promise within the American mining landscape. Its current resource estimate comprises a substantial 54.2 million tonnes (mt) of measured and indicated material, boasting an average grade of 1.51% copper. Highland Copper’s strategic operational review, spurred by a backdrop of significantly improved long-term consensus copper prices, is poised to unlock further value from this resource, making its development a key focus for the company and a point of interest for the broader industry.

Strategic Optimization Initiatives Underway

A core component of Highland Copper’s ongoing work involves a meticulous evaluation of the project's economic parameters and resource utilization. This review centers on several key areas:

• Cut-Off Grade Reassessment: The company is critically assessing whether to lower the cut-off grades currently used to define mineable resources. This evaluation is based on a robust long-term copper price assumption of approximately $4.8/lb. A reduction in cut-off grades could be instrumental in expanding the project’s mine plan by enabling the inclusion of additional measured and indicated mineral resources that may have previously been deemed uneconomic. This strategy is commonplace in a rising commodity price environment, as it allows for the conversion of lower-grade material into economically viable ore.
• Bulk Ore Sorting Technologies: Highland Copper is diligently examining the potential application of bulk ore sorting technologies. Should these technologies prove viable upon further testing, they could offer a transformative pathway to integrate the upper copper bearing sequence (UCBS) into future mine plans. The UCBS currently represents a significant 10.2 mt at a grade of 1.1% copper within the measured and indicated category but is presently excluded from the project’s declared mineral reserves. Mechanically pre-concentrating the ore through sorting could significantly improve feed grades to the processing plant, thereby enhancing overall project economics.

These initiatives underscore Highland Copper's commitment to maximizing the value of the Copperwood deposit through innovative technical and strategic approaches, adapting to the evolving market dynamics and technological advancements in the mining sector.

Refining Resource Estimates and Mine Design

Beyond resource definition, Highland Copper is also deeply engaged in refining the fundamental aspects of mine design and operational efficiency. Geotechnical investigations are playing a pivotal role in this process, providing crucial data to optimize several critical design elements:

• Mining Heights: Precise determination of optimal mining heights is essential for maximizing ore recovery while minimizing dilution and operational costs in underground mining environments.
• Pillar Dimensions: Geotechnical data is vital for ensuring the stability of underground workings by correctly sizing rock pillars, a key safety and operational consideration.
• Dilution Sources: Current work suggests an important refinement in understanding potential dilution. Initially, dilution might have been assumed to primarily originate from the floor of the mining areas. However, ongoing investigations indicate that dilution could instead be sourced from the mineralized hanging wall. This distinction is operationally significant, as it can influence blasting patterns, ore recovery strategies, and overall grade control within the mine.

These detailed studies are designed to produce a more robust, efficient, and safe mine design, ultimately contributing to the project’s long-term operational success and economic viability.

Advancements in Metallurgical Processing

Metallurgical efficiency is a cornerstone of any successful mining operation, particularly for polymetallic deposits like Copperwood. Last September, Highland Copper completed crucial metallurgical test work that evaluated an alternative mill-float-mill-float processing flowsheet. This advanced flowsheet builds upon traditional flotation methods to achieve superior metal recovery.

The results of this test work were highly encouraging, projecting significant improvements for the Copperwood project:

• Increased Copper Recovery: The company now projects an average life-of-mine copper recovery of approximately 87.6%. This represents a notable improvement from the 86% recovery rate outlined in the 2023 feasibility study. Even minor percentage gains in recovery can translate into substantial increases in overall metal production and revenue over the life of a mine.
• Reduced Secondary Milling: The new flowsheet anticipates lower secondary milling requirements, indicating a more efficient liberation of target minerals earlier in the process.
• Lower Energy and Reagent Use: Improved processing efficiency is also expected to lead to reduced consumption of energy and chemical reagents, which are major operating costs for concentrators. This not only enhances economic performance but also contributes to a smaller environmental footprint.

While these projections are based on rigorous test work and engineering assumptions, Highland Copper responsibly notes that they "may differ under operational conditions." This underscores the inherent complexities of scaling laboratory and pilot plant results to full-scale commercial operations, a recognized challenge across the mining industry.

Tailings Management Innovations

Sustainable and cost-effective tailings management is a critical aspect of modern mine development. Highland Copper is exploring innovative solutions in this area, specifically focusing on thickened tailings technology. Test work conducted at Responsible Mining Solutions in Sudbury, Ontario, Canada, demonstrated the successful production of thickened tailings with approximately 55% solids by mass for the Copperwood project.

The adoption of a thickened tailings approach provides several compelling benefits:

• Reduced Facility Size: Thickened tailings have a higher density and require less storage volume, which could significantly decrease the physical footprint of the tailings deposition facility, minimizing land disturbance.
• Lower Construction Costs: A smaller facility often translates directly to lower initial capital construction costs, a major advantage for large-scale mining projects.
• Improved Process Water Recovery: Thickened tailings typically release more process water, enabling higher rates of water recycling back into the plant. This reduces reliance on fresh water sources and minimizes discharge, enhancing environmental stewardship.
• Lower Pumping Expenses: Efficient water recovery and reduced overall volume can also lead to lower pumping expenses over the life of the operation.

These advancements in tailings management reflect an industry-wide push for more environmentally sound and economically efficient waste disposal practices.

Leadership Perspective and Market Context

Highland Copper CEO Barry O’Shea articulated the strategic importance of these ongoing efforts. “As we continue our integrated mine plan review against a backdrop of significantly improved long-term consensus copper prices, we are encouraged by the opportunities to further optimise Copperwood through mine design, processing and engineering enhancements,” Mr. O’Shea stated. His comments highlight the synergistic effect of a strong commodity market and focused technical innovation.

Mr. O’Shea further emphasized the broader implications, noting that “These initiatives have the potential to strengthen project economics and will be incorporated into the updated feasibility study.” He also pointed to Copperwood’s unique position: “With Copperwood advancing towards a construction decision, the project is entering an increasingly important stage of development at a time when few new copper projects are positioned to come online in the US in the near term.”

This statement resonates deeply within the US mining industry, where a drive for domestic supply chain security and the rising global demand for critical minerals—particularly copper for electrification and renewable energy technologies—is creating a significant impetus for new project development. New copper projects of Copperwood’s scale are indeed rare in the US, positioning it as a potentially vital asset for national mineral supply.

Path Towards Financing and Construction

The updated feasibility study in Q1 2027 is a pivotal deliverable that will synthesize all the optimization work and provide the definitive technical and economic blueprint for Copperwood. Prior to this, Highland Copper is targeting the completion of 40% of the front-end engineering and design (FEED) by the end of 2026. This significant engineering milestone is crucial for preparing the comprehensive technical documentation required for future project financing and rigorous technical due diligence by potential lenders and investors.

The progression of Copperwood towards a construction decision is being closely watched. Should the updated feasibility study confirm robust economics and the company successfully secures financing, the project has the potential to become a significant new source of copper production in the United States. This would not only enhance Highland Copper’s standing but also contribute meaningfully to the nation's efforts to secure critical mineral supplies essential for its economic and technological future.

The next 12 to 18 months will be transformative for the Copperwood project, as Highland Copper moves from detailed studies to a definitive project plan, aiming to capitalize on the strong copper market and bring a new domestic copper mine online.