Cinder Cone, to the east of The Black Tusk, produced a 9-km-long lava flow during the late Pleistocene or early Holocene.

Mount Price, west of Garibaldi Lake, 5 km (3.1 mi) south of The Black Tusk, was formed in three stages of activity, dating back 1.1 million years, the latest of which produced two large lava flows from Clinker Peak during the early Holocene that ponded against the retreating continental ice sheet and formed The Barrier, containing Garibaldi Lake.

The Table is a steep-sided andesite tuya, situated approximately 3 km southwest of Mount Price and south of Garibaldi Lake.

The unstable lava formation of The Barrier has in the past unleashed several debris flows in the area below the lake, most recently in 1855–56 forming a large boulder field which gives Rubble Creek its name.

Concerns about the Barrier's instability due to volcanic, tectonic, or heavy rainfall activity prompted the provincial government to declare the area immediately below it unsafe for human habitation in 1981.