Dakota Gold Advances Richmond Hill Gold Project With New Recovery Data and Heap-Leach Design

Key Points

• Dakota Gold has received the final assay results needed for its Richmond Hill pre-feasibility study resource update, expected alongside the study in the fourth quarter of 2026.
• Metallurgical testing showed modeled average ultimate gold recovery of 80.4% for oxide material crushed to 0.5 inch, compared with 75.9% at 1 inch.
• The company selected a single heap-leach facility instead of multiple locations to simplify the project layout.
• The updated Richmond Hill resource model will incorporate 42,791 meters of drilling from 2025 and 2026 and focus on oxide material.
• Dakota Gold expects to publish a Richmond Hill feasibility study in mid-2027 and resume Maitland drilling in the first half of 2027.

Dakota Gold (NYSE: DC) is moving its Richmond Hill oxide heap-leach gold project in South Dakota toward a pre-feasibility study, or PFS, after receiving the final assays for its resource update and choosing key processing and site-layout designs. The decisions give the company a clearer basis for estimating project costs, planning operations and evaluating Richmond Hill’s economics later this year.

Richmond Hill Gold Recovery Testing Supports 0.5-Inch Crush Size

Dakota Gold selected a 0.5-inch, or 12.7-millimeter, design crush size for Richmond Hill after comparing processing options. Metallurgical testing showed modeled average ultimate gold recovery of 80.4% for oxide material at 0.5 inch, versus 75.9% at a 1-inch crush size.

That 4.5-percentage-point difference will be reflected in the upcoming PFS financial model, according to the company. The recovery figures are based on testing and modeling, not gold produced by an operating mine.

Single Heap-Leach Facility Simplifies Richmond Hill Site Design

Dakota Gold also chose one heap-leach facility, generally within the area identified for Phase 1 in its earlier Initial Assessment with Cash Flow. The company had previously considered multiple facility locations.

A single site is intended to simplify ore handling, stacking, solution collection and long-term facility management. Dakota Gold said it will also concentrate liner preparation, geotechnical design and monitoring in one principal location. The selected layout and crush size will feed into the PFS capital estimate, operating plan, permitting design and economic model.

Final Richmond Hill Assays Will Update Oxide Gold Resource Model

The company has received the final assay results required for the PFS resource update. Its revised model will incorporate 333 holes drilled in 2025 and 2026, totaling 42,791 meters—approximately 30% more drilling data than the prior resource model.

The new PFS model will focus entirely on oxide material. Dakota Gold said it will exclude transition material, which made up roughly 18% of the heap-leach material in the prior resource, based on the criteria established through its metallurgical testing.

Dakota Gold is combining the assay results with geological, metallurgical and geochemical information to refine resource classification, mine sequencing and the production schedule. The supplied announcement refers to a table of additional assay results but does not include the individual drill intercepts or grades.

Dakota Gold Targets Mid-2027 Richmond Hill Feasibility Study

Two drills are currently working at Richmond Hill on data for the next stage of study. The program includes drilling intended to support potential conversion of inferred resources and additional metallurgical testing across the project’s principal rock types and mineralized zones.

That testing will help Dakota Gold build a more detailed gold-recovery model and refine its plans for moving and stacking material on the heap-leach facility. The company expects to publish the Richmond Hill feasibility study in mid-2027.

Maitland Gold Project Drilling Expected to Resume in 2027

At the nearby Maitland Gold Project, Dakota Gold has received initial results covering 791 meters of a planned 5,578-meter drilling campaign aimed at establishing a maiden resource for the Unionville Zone.

The company redirected drilling capacity to Richmond Hill after favorable metallurgical results from oxide material there. Dakota Gold expects to resume Maitland drilling and complete the planned program in the first half of 2027, with further results to be reported as assays are received and reviewed.