<Li> Mount Mazama, which erupted catastrophically in 5670 BCE to form Crater Lake . </Li> <Li> Mount Meager massif erupted about 2350 BP, sending an ash column 20 km (12 mi) high into the stratosphere . </Li> <Li> Mount Edziza volcanic complex, Canada's second largest eruptive center, erupted about 1340 BP . </Li> <Li> Medicine Lake Volcano erupted about 1000 BP . </Li>

This region of the pacific northwest was formed by voluminous fissure eruptions