Sitka’s Blackjack underground mine potential: key drilling insights for planners
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
High-grade deep drilling at Sitka Gold’s RC Gold project in Yukon indicates underground mine potential beneath the Blackjack deposit, with hole DDRCCC-26-121 cutting 273.8 m at 1.10 g/t Au from about 642 m depth, including 94 m at 1.79 g/t and 19.3 m at 5.04 g/t. The 1,093 m hole extends mineralisation roughly 370 m below the current resource pit and is the first complete assay from a 60,000 m, four-rig diamond programme now about 20% complete. Blackjack currently hosts 39.96 Mt indicated at 1.01 g/t Au (1.29 Moz), within a 447 sq.-km land package in the Tombstone belt accessible year-round by gravel road.
Technical Brief
- Drillhole DDRCCC-26-121 is the deepest at RC Gold to date at 1,093 m total depth.
- Current 60,000 m diamond drilling campaign is planned to double total drilled metres on the project.
- About 50% of this season’s drilling is allocated to the Rhosgobel deposit for resource growth.
- Four diamond rigs are operating concurrently, with the 2026 programme reported as ~20% complete.
- Blackjack’s January 2025 indicated resource: 39.96 Mt at 1.01 g/t Au for 1.29 Moz contained.
- Inferred at Blackjack: 34.6 Mt at 0.94 g/t Au for 1.04 Moz, all starting at surface.
- Combined RC Gold inferred (Blackjack, Rhosgobel, Eiger): 167.4 Mt at 0.72 g/t Au for 3.83 Moz.
- All three deposits are modelled as surface-starting, potentially open-pit minable systems within a 447 km² land package.
- Site access is via a secondary gravel road off the Klondike Highway, usable year-round ~100 km from Dawson City.
- For Yukon intrusion-related gold systems, such deep step-out intercepts materially influence underground versus expanded-pit trade-off studies.
Our Take
The deep, higher-grade intercepts at the Blackjack deposit suggest a potential transition from a purely open-pit concept to a combined open-pit/underground scenario, which typically improves project optionality but can complicate sequencing and capex planning for mid-tier developers like Sitka Gold.
PwC Canada’s BC Mine 2025 report on British Columbia and Yukon warns that slow permitting and grid expansion could push gold and critical minerals investment to the US and Australia; if those bottlenecks persist, a large, road-accessible project like RC Gold east of Dawson City may still face long lead times despite its scale and proximity to existing mines such as Eagle and Brewery Creek.
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.
Related Articles
Related Industries & Products
Mining
Geotechnical software solutions for mining operations including CMRR analysis, hydrogeological testing, and data management.
Tunnelling
Specialised solutions for tunnelling projects including grout mix design, hydrogeological analysis, and quality control.
CMRR-io
Streamline coal mine roof stability assessments with our cloud-based CMRR software featuring automated calculations, multi-scenario analysis, and collaborative workflows.
HYDROGEO-io
Comprehensive hydrogeological testing platform for managing, analysing, and reporting on packer tests, lugeon values, and hydraulic conductivity assessments.
GEODB-io
Centralised geotechnical data management solution for storing, accessing, and analysing all your site investigation and material testing data.


