 This makes Kostal Cone the youngest volcano in the Wells Gray-Clearwater volcanic field and thus one of the youngest in Canada.Tseax Cone, a young cinder cone at the southernmost end of the Northern Cordilleran Volcanic Province, was the source for a major basalt lava flow eruption around the years 1750 and 1775 that travelled into the Tseax River, damming it and forming Lava Lake.The lava flow subsequently travelled north to the Nass River, where it filled the flat valley floor for an additional , making the entire lava flow long.