The Big K area is underlain by rocks of the Lower Jurassic Unuk River Formation (Hazelton Group). Rocks in the area consist of volcanic breccia and andesite tuff, with interbedded siltstone, argillite and conglomerate. The area lies within the Portland Canal dike swarm, which consists generally of granodiorite/quartz diorite dikes.

The Big K is an area where 3 holes were drilled by Ascot Resources in 2008 adjacent to the Granduc road. The main target was a large radiometric anomaly. Two 2007 chip lines sampled along the road (samples 48035-48050) assayed 0.5 grams per tonne gold, 9 grams per tonne silver, 0.28 per cent lead and 0.87 per cent zinc over 16 metres; and (samples 49610-49627) assayed 0.5 gram per tonne gold, 11 grams per tonne silver, 0.31 per cent lead and 0.28 per cent zinc over 17 metres (Assessment Report 31000). Anomalous soils contributed to the potential of this area.

Drillhole HL08-55 was drilled northeast through the anomaly and across the Dumas Creek fault. A small series of dikes were intersected along the fault and a mineralized zone in the footwall. A 9 metre drill intersection assayed 1.0 gram per tonne gold and 12 grams per tonne silver (Assessment Report 31000). The zone is dark grey-black, fine-grained mudstone-rich volcanic rock. It is silicified with some quartz stockwork and pyrite.

See Yellowstone (MINFILE 104B 039) for related information and common work history on Dilworth property.