The fifth and final phase of eruptive activity occurred from secondary volcanic vents along the flanks of the four central volcanoes starting 10,000 years ago. This phase of activity began at a time when remnants of glacial ice were still present and continued after the glacial period. The initial flank eruptions, quenched by glacial meltwater, formed hyaloclastite tuff rings, whereas later activity created 30 small cinder cones, primarily of basaltic composition, 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 earlier than the year 700 based on the age of burnt plant stems still rooted in former soil under of loose basaltic fragments. These cinder 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 150 km2. The longest lava flow is . This volcanic activity was followed by at least two younger, but still undated eruptions, including an undated air-fall pumice deposit.