Yellowstone: This name is used to mark any time the
Yellowstone hotspot has erupted since the end of the last Ice Age.
Yellowstone-1: Erupts during the Seven Years War.
Yellowstone-2: Erupts during the Mexican American War.
Yellowstone-3: Erupts just before WWII.
Yellowstone-4: This hell parallel was named erroneously: it's actually the result of super-science "mega nukes" setting off a chain reaction of volcanoes around the world.