Volcano Mountain is the youngest volcano in the Fort Selkirk Volcanic Field and one of the youngest in the northern section of the Northern Cordilleran Volcanic Province. The lava at Volcano Mountain is olivine nephelinite, which is an uncommon type of lava. This type of lava is believed to have come from much deeper inside the Earth than basaltic lava. The last eruption from Volcano Mountain produced young nephelinitic lava flows that remain unvegetated and appear to be only a few hundred years old. However, dating of sediments in lake impounded by the lava flows indicate that the youngest flows could not be younger than mid-Holocene and could be early Holocene or older.