Dakota Gold Corp. (NYSE American: DC) is pleased to provide an update on its Richmond Hill Oxide Heap Leach Gold Project and Maitland Gold Project, both located on private land in the Homestake District of South Dakota. The Company has concluded key process and site-layout trade-off studies for the Richmond Hill Pre-Feasibility Study and received additional assay results that will be incorporated into the Feasibility Study  resource update. These milestones provide greater definition for the resource model, process design and infrastructure configuration.

Highlights From This Update Include:

• Completion of key PFS trade-off studies simplifies execution plan: The Company has completed two important trade-off studies and selected a 0.5-inch (12.7-millimeter) design crush size and a single heap-leach facility located generally within the area identified for Phase 1 in the Initial Assessment with Cash Flow. The decisions reflect favorable metallurgical recovery results and will simplify operations and reduce geotechnical and execution risk relative to a multiple-facility configuration.
• Final Richmond Hill assays received: The Company has received the final assay results required for the Richmond Hill PFS resource update. The complete assay dataset is being incorporated into the updated resource model and mine plan for inclusion in the upcoming PFS. With the results a total of 42,791 meters (140,389 feet) of drilling from 2025 and 2026 were added to the upcoming resource update to be released in conjunction of the PFS in the fourth quarter of this year.
• Work on FS underway: The Company is currently operating with two drills to convert additional inferred resource material to reserve category post-PFS into a FS mine plan. A portion of this drilling is dedicated to producing additional samples to complete the FS level of metallurgical variability testing across the dominant lithologies and geo metallurgical domains. The FS is expected to be published mid-2027.

Jack Henris, Chief Executive Officer, President and Director of Dakota Gold, said, “Receipt of the final Richmond Hill assays is an important milestone as we complete the dataset for our upcoming PFS resource update expected to be released in conjunction with our PFS in the fourth quarter of this year. We have also concluded two significant trade-off studies by selecting a 0.5-inch design crush size and a single heap-leach facility in the area contemplated for Phase 1 of the IACF. Together, these decisions support a simpler operating configuration, reduce geotechnical complexity and provide greater definition for the overall PFS design.”

Richmond Hill Process and Site-Layout Trade-Off Studies

Dakota Gold has completed the PFS trade-off evaluation of the primary crushing options and selected a 0.5-inch (12.7-millimeter) design crush size. Recent metallurgical testing indicated modeled ultimate gold recovery for oxide material averaged 80.4% at a 0.5-inch crush size, compared with 75.9% at a 1-inch crush size. The PFS financials will capture this benefit when it is released later this year.

The updated resource informing the PFS will incorporate 333 drill holes completed in 2025 and 2026, representing 30% more drilling data from the prior resource, and will be entirely focused on oxide material. The metallurgical test program results defined oxide material as having a CN/FA ratio ≥0.82 and total sulfur content ≤0.5%. Therefore, the PFS will exclude transition material, which represented roughly 18% of the heap leach material in the prior resource.

The Company has also selected a single heap-leach facility located generally within the area identified for Phase 1 in the IACF, rather than the multiple conceptual heap-leach areas previously considered. The consolidated configuration (see Figure 1) will simplify material handling and solution management, optimize operation and consolidate the geotechnical design and monitoring program within one operational area.

This selection will reduce operational complexity and provide a more integrated approach to heap leach facility construction, stacking, solution collection, and long-term facility management. From a geotechnical perspective, a single facility allows the Project team to focus design, liner system preparation, solution management and monitoring in one principal location. The combined crush-size and heap-location decisions provide important inputs to the PFS capital estimate, operating plan, permitting design and economic model.

Figure 1. Richmond Hill IACF conceptual mine site layout with updated single leach pad location for PFS.

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Richmond Hill Final Assays and PFS Integration:

Dakota Gold has received the final assay results from the Richmond Hill drilling datasets required to complete the resource-model update supporting the PFS. The results are being integrated with geological, metallurgical and geochemical information to finalize resource classification, mine sequencing and the production schedule. Completion of this assay dataset closes a key technical workstream for the PFS and provides the basis for the updated resource and reserve evaluation.

The Company is excited to include the completed assay dataset in the upcoming PFS. The updated model will also incorporate the results of the recent metallurgical program, including the strong recovery response from breccia-hosted oxide material, to support recovery assignment, ore routing and mine-sequencing decisions.

Additional assay results, which are reported here (see Table 1), represent 3,002 meters (9,847 ft) of geotechnical drilling conducted after the PFS drilling was completed, as well as Chism Gulch phase 2 definition drilling designed to convert remaining inferred blocks for the FS.

Progress on FS:

Along with the additional drilling in the central Richmond Hill area with oxide-breccia hosted material, the Company has planned additional metallurgical holes to complete the testing as part of the FS. The current planned variability testing scope includes:

• New metallurgical hole core logging and sample preparation
• Head sample compositing and characterization
• Bottle-roll testing
• Column testing (60 day fixed interval) on 30 to 40 master-composite columns across geometallurgical domains and 4 primary lithologies
• Select tails deportment as necessary
• ABA geochemistry, acid mobility testing and modeling, and sulfide reactivity
• Standard preg rob suite
• Mercury solution balance
• Zinc precipitation performance mapping
• Geotechnical testing on column tails – Compact permeability, direct shear, LA abrasion, and slake durability testing

This round of metallurgical variability testing is in direct support of the FS that complements the suite of testing completed during the PFS, and meets the requirements for adequate statistical representation of material types and quantities in the plan at the FS level. The FS test data will allow us to complete a more rigorous metal recovery model and metal plan which will assist in improved mine planning and sequencing. Expected outputs from this effort will include:

• Detailed stacking plan development
• Detailed working recovery model and preliminary metal plan
• Mine-to-heap modeling that allows for optimized stacking and recovery review iterations
• Optimized final metal plan, optimized mine schedule, life of plan

Maitland Drilling Update:

Initial drill results have been received representing 791 meters (2,594 feet) of drilling from the 5,578 meter (18,300 feet) campaign to produce a maiden resource for the Tertiary epithermal Unionville Zone (see Table 2). In response to the strong metallurgical results from breccia-hosted oxide material at Richmond Hill, Dakota Gold redirected drilling capacity to the central Richmond Hill area to prioritize definition and metallurgical drilling that can inform Feasibility Study mine sequencing and resource conversion opportunities.

The Company expects to resume drilling at Maitland and complete the planned program for the maiden resource in the first half of 2027. The revised schedule reflects disciplined allocation of drilling resources to near-term technical priorities at Richmond Hill and does not change Dakota Gold’s long-term view of Maitland’s high-grade exploration potential. Additional Maitland results will be reported as assays are received, reviewed and interpreted.

About Dakota Gold Corp.

Dakota Gold is a responsible exploration and development company advancing the Richmond Hill Gold Project toward production as soon as 2029, while continuing to define and expand the high-grade underground gold resource potential at the Maitland Gold Project. Both projects are located on private land within the historic Homestake District of South Dakota, one of the most prolific gold mining regions in the United States.

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Qualified Person and S-K 1300 Disclosure

William Gehlen, a Certified Professional Geologist (CPG-10626) with the AIPG, American Institute of Professional Geologists, a Senior Fellow with the SEG, and Senior Manager – Geology of Dakota Gold Corp., is the Company’s designated qualified person (as defined in Subpart 1300 of Regulation S-K) for this news release and has reviewed and approved its scientific and technical content.

Quality Assurance/Quality Control consists of regular insertion of certified reference materials, duplicate samples, and blanks into the sample stream. Samples are submitted to the ALS Geochemistry sample preparation facility in Winnipeg, Manitoba. Gold and multi-element analyses are performed at the ALS Geochemistry laboratory in Vancouver, British Columbia. ALS Minerals is an ISO/IEC 17025:2017 accredited lab. Check samples are submitted to Bureau Veritas, Vancouver B.C. as an umpire laboratory. Assay results are reviewed, and discrepancies are investigated prior to incorporation into the Company database.

Appendix:

Richmond Hill Gold Project Assay Results:

Table 1. Richmond Hill drill results (Metric / Imperial)^1,2,3,4,5

Maitland Gold Project Assay Results:

Table 2. Maitland Gold Project initial drilling assay results from 2026 infill drill campaign. (Metric / Imperial)^1,2,3