The Bigtime A occurrence is located just southwest of Ominicetla Creek about 200 kilometres northwest of the community of Fort St. James.

The Bigtime A showing area is underlain primarily by the Lower Jurassic Telkwa Formation (Hazelton Group) consisting of a sequence of subaerial to submarine calc-alkaline island arc volcanic and sedimentary rocks. Cretaceous to Eocene volcanic and sedimentary rocks of the Sustut Group are also present. The Telkwa Formation rocks are intruded by small plugs of quartz and hornblende feldspar porphyry of unknown age and a large plug of biotite hornblende diorite of Late Jurassic age.

A zone of quartz-flooded intrusive rock(?) contains disseminated pyrite, chalcopyrite and abundant malachite and azurite staining. In 2009, a series of 5-metre chip samples were collected (samples 880684-695). Values indicated on Figure 8.5 (Assessment Report 31410) range up to 0.35 per cent copper (sample 880690), though not all samples indicated on the figure are necessarily 5-metre chip samples. The disseminated mineralization is associated with multiple sub-parallel felsic dikes intruding Hazelton Group mafic flows and tuffs.

In 2009, Amarc Resources Ltd. completed a program of geological mapping, prospecting, rock (184) and soil (519) sampling, and an induced polarization survey (11.7 kilometres).

See Lion (093M 146), located 1.4 kilometres north, for details on the Bigtime A work history.