Therefore, the exact age for the most recent eruptions at Volcano Mountain are unknown. At the southernmost end of the Northern Cordilleran Volcanic Province, Tseax Cone lies in a valley above and east of the Tseax River. It is a young Holocene age cinder cone that 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. Native legends from Nisga'a people in the area tell of a prolonged period of disruption by the volcano, including the destruction of two Nisga'a villages known as Lax Ksiluux and Wii Lax K'abit. Nisga'a people dug pits for shelter but at least 2,000 Nisga'a people were killed due to volcanic gases and poisonous smoke (most likely carbon dioxide). This is Canada's worst known geophysical disaster and is the only eruption in Canada for which legends of First Nations people have been proven true. As of 1993, the Tseax Cone quietly rests in Nisga'a Memorial Lava Beds Provincial Park. More than 20 eruptions have occurred at the Mount Edziza volcanic complex in the past 10,000 years, including Mess Lake Cone, Kana Cone, Cinder Cliff, Icefall Cone, Ridge Cone, Williams Cone, Walkout Creek Cone, Moraine Cone, Sidas Cone, Sleet Cone, Storm Cone, Triplex Cone, Twin Cone, Cache Hill, Camp Hill, Cocoa Crater, Coffee Crater, Nahta Cone, Tennena Cone, The Saucer and the well-preserved Eve Cone. These cinder cones were formed no more than the year 700 based on the age of burnt plant stems still rooted in former soil under of loose basaltic fragments. The cones were built on the basaltic fragments and blocky lava fields surrounding the cones. The Snowshoe Lava Field on the southern end of the Big Raven Plateau is one of the areas of young lava flows in the region while the Desolation Lava Field on the northern end of the Big Raven Plateau is the largest area of young lava flows, covering an area of . The longest lava flow is .