The Mack showing is located on Lunar Creek roughly 24 kilometres north of the confluence of Lunar Creek with Geese Creek, north of the Stikine River. Dease Lake is 135 kilometres to the northwest.

Regionally, the Mack showing lies on the western edge of the Omineca Belt near the Kutcho fault, marking the boundary with rocks of the Intermontane Belt. The showing is along the margin of an unnamed Late Triassic to Early Jurassic granitoid pluton. At this showing the composition of this pluton is hornblende monzonite and biotite quartz monzonite. To the west lies the Middle Triassic Lunar Creek Complex.

The copper showing is underlain by hornblende quartz monzonite. To the south of the Mack showing, the area is underlain by biotite quartz monzonite. Local skarn horizons occur throughout. Some are interbedded with metasediments and gneiss.

The area has been explored in conjunction with the nearby West 16 (MINFILE 094E 010) occurrence and a complete work history of the area and property can be found there.