The MacMillan occurrence is located south of an un-named tributary of Wolf Creek, approximately 12.5 kilometres south west of Nanaimo.

The area is underlain primarily by massive basalts of the Upper Triassic Karmutsen Formation (Vancouver Group) intruded by granodiorite and hornblende diorite of the Early to Middle Jurassic Island Plutonic Suite. Sandstone, pebbly sandstone and conglomerate of the Cretaceous Nanaimo Group unconformably overlies this sequence.

Mineralization occurs in a breccia zone near the Nanaimo Group- Karmutsen Formation contact. The zone is buff coloured, siliceous and comprised of quartz, chalcedony, ankerite(?), calcite and hema- tite. Sulphide content is low and occurs in the siliceous matrix or in widespread stockwork fractures and consists of tetrahedrite, bornite, chalcocite, pyrite and chalcopyrite. Native arsenic(?) and corynite(?) is also reported (Assessment Report 13451).

In 1983 through 1986, the area was explored as the TEL 1-4 claims by T.E. Lisle. During this time programs of geochemical sampling, prospecting, trenching and a ground magnetometer geophysical survey were completed. In 1984, a trenched rock sample assayed 8.9 per cent copper and 20.5 grams per tonne silver (Assessment Report 13451).

In 1986, a rock sample from a trenched area on this zone assayed 16.6 grams per tonne silver (Assessment Report 14496).

In 1987, Chevron Canada Resources completed programs of geological mapping and rock and soil geochemical sampling on the TEL 1-4 and nearby Jack (MINFILE 092F 185) claims. In 1990, T.E. Lisle completed a program of geological mapping and ground electromagnetic and magnetic geophysical surveys.