Dakota Gold’s Richmond Hill: step-out drilling and NPV lens for mine planners
Reviewed by Tom Sullivan
First reported on MINING.com
30 Second Briefing
New drilling at Dakota Gold’s Richmond Hill oxide heap-leach project in South Dakota has extended mineralisation at least 260 metres north of the current measured and indicated boundary, with step-out hole RH25C-359 cutting 13 metres at 3.14 g/t gold and 10.57 g/t silver from 99 metres depth, open in all directions. Additional intercepts include 6 metres at 2.53 g/t gold from 55 metres in BG-GW-11 and 9 metres at 1.42 g/t gold from 37 metres in BG-GW-13, feeding into a 2026 pre-feasibility and reserve declaration. The project currently hosts 244.7 million measured and indicated tonnes at 0.46 g/t gold and 4.83 g/t silver, underpinning a 28-year mine life and post-tax NPV of $1.6–2.1 billion with a 55–59% IRR and $384 million initial capex.
Technical Brief
- 7,565 metres drilled since Jan. 1, nearly half of Dakota Gold’s full-year drilling budget.
- The exploration campaign includes 109 holes covering 15,481 metres, consisting of a combination of infill, expansion, geotechnical and mine plan drilling.
- Last year’s drill campaign included 242 holes over 29,524 metres.
- Richmond Hill sits in the historic Homestake mining district, which has produced more than 40 million oz. gold over its 145-year history.
- Richmond Hill could produce 2.6 million to 3.9 million oz. of gold over a potential mine life of 28 years, according to an S-K 1300 Initial Assessment report from July.
- Dakota Gold’s CEO, Robert Quartermain, previously built Pretium Resources and developed the Brucejack mine in British Columbia before agreeing to be bought by Newcrest – now Newmont Mining – for about C$3.5 billion.
Our Take
With a projected post-tax NPV of US$1.6–2.1 billion against initial costs of US$384 million, Richmond Hill screens as one of the stronger economic profiles among gold Projects pieces in our database, which is likely to keep Dakota Gold on the radar of larger producers already active in the USA.
The combination of low-grade bulk-tonnage resources at Richmond Hill (0.46 g/t Au M&I) and the Homestake district’s 40 Moz historic output suggests operators will need to lean heavily on heap-leach efficiency and tight operating cost control to defend margins if gold prices soften.
Targeting reserves by 2026 and first production in 2029 puts Dakota Gold’s South Dakota asset on a similar development horizon to several other North American gold projects in our coverage, which could intensify competition for engineering contractors and skilled labour in the mid- to late-2020s.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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