 It consists of mostly monogenetic scoria cones, each of which produced three or four lava flows.There are at least 22 cones, and all volcanic landforms older than 12,000 years have been glaciated, the oldest the Soda Peaks basalt lava flows, dated to 0.36 million years old.The West Crater-Soda Peaks zone covers an area of , to the southeast of Mount St. Helens.