Top 20 copper drillers: Andes dominate

The Northern Miner’s list of top 20 copper drill results in this year’s first half reflects the strong exploration momentum in the Andes of Chile and Argentina, as well as Mongolia, which all boasted long high-grade intercepts.  

Ranked by grade-times-interval – a measure that emphasizes both grade and thickness – the first half of 2025 was led by a handful of long runs of moderate copper mineralization rather than short, spectacular spikes. 

Entrée Resources (TSX: ETG) tops the ranking at the Hugo North Extension (HNE) deposit within the Oyu Tolgoi joint venture in Mongolia. Hole EGD189B cut 552 metres grading 2.3% copper from 1,226 metres depth, giving it the highest grade-times-interval of the period. The company called the EGD189B result “some of the best we’ve received since HNE deposit drilling restarted in 2022.” 

Entrée also reported underground hole UGD807C, which intersected 456 metres at 1.19% copper from 205 metres. Continued work at HNE remains a priority in 2025, Entrée said. The drilling is intended to help plan future mine planning alongside Rio Tinto’s (NYSE, LSE, ASX: RIO) underground expansion schedule at Oyu Tolgoi, one of the world’s largest copper-gold operations.  

The Entrée/Oyu Tolgoi joint venture property has 40 million tonnes of probable reserves grading 1.5% copper, 0.53 gram gold per tonne and 3.6 grams silver, for 1.34 billion lb. copper, 676,000 oz. gold and 4.61 million oz. silver, according to a 2021 feasibility study. 

Oyu Tolgoi is owned 66% by Rio Tinto and 34% by Mongolia; Entrée holds a participating interest in the Hugo North Extension within the broader complex.  

Argentina

NGEx Minerals (TSX: NGEX; US-OTC: NGXXF) occupies the next positions from its Lunahuasi project in San Juan province, Argentina. Hole DPDH027 ranks highly by grade times interval on the strength of its length, returning about 1,619 metres at 0.52% copper from 386 metres depth.  

Two other Lunahuasi holes also place near the top of the list, reflecting a pattern of multi-hundred-metre runs with copper grades that score well once length is factored in. The company’s plan is to keep stepping out and to prepare for further drilling aimed at expanding the Lunahuasi footprint within the Vicuña District. 

Stage three drilling at Lunahuasi “has rapidly expanded the minimum north–south, east–west and vertical distances of the mineralized volume to well over one kilometre,” NGEx President and CEO Wojtek Wodzicki said in May. “This unique combination of high grades and significant scale strongly emphasizes the potential exhibited by the vein-hosted mineralization.”  

Although economic studies have not been released yet, the combination of scale, continuity and emerging high-grade zones positions Lunahuasi for potential open-pit development, the company said in May. At an assumed copper price of $3 per lb. and defined recoveries, NGEx noted that an inferred resource of 1.4 billion tonnes grading about 0.45% copper equivalent could imply a project value exceeding $18 billion. 

Chile

ATEX Resources (TSX-V: ATX) also features prominently with two long intervals from its Valeriano copper-gold project in Chile. Hole ATXD23A returned about 1,220 metres at 0.66% copper from 822 metres depth, while ATXD28 delivered about 1,090 metres at 0.56% copper from 834 metres.  

The Valeriano project hosts 1.41 billion inferred tonnes grading 0.5% copper, 0.2 gram gold per tonne and 0.96 gram silver for 1.8 million tonnes of contained copper, 1.84 million oz. gold and 8.6 million oz. silver, according to a 2023 report. An update is due this year.  

With up to C$55 million in backing from Agnico Eagle Mines (TSX, NYSE: AEM), the company says it is well capitalized to advance through further drilling, metallurgical work and engineering scoping studies ahead of resource conversion and prefeasibility stage planning. It wants to frame the project at a scale that would appeal to strategic partners.  

Serbia

Dundee Precious Metals (TSX: DPM) features with drilling from its Čoka Rakita project in Serbia, where work at the Dumitru Potok prospect returned wide copper-bearing intervals. The company says it is “accelerating its systematic target delineation drilling campaign at Dumitru Potok to further extend these high-grade zones” while moving Čoka Rakita through studies toward a development decision.  

Dundee forecast in February that a pre-feasibility study and a path toward first concentrate production would happen in this decade. 

Peel Mining (ASX: PEX) appears via hole WTRC279 at the Wagga Tank prospect in New South Wales, where copper-rich supergene zones at shallow depths helped propel the intercept into on ninth place on our list.  

The company continues to advance Wagga Tank within its South Cobar project, and said in August it’s working towards a pre-feasibility study. Peel has emphasized near-surface potential at Wagga Tank.