Mesa Falls Tuff

The Mesa Falls Tuff is a tuff formation produced by the Mesa Falls eruption that formed the Henry's Fork Caldera that is located in Idaho west of Yellowstone National Park.[1] It is the second most recent caldera forming eruption from the Yellowstone hotspot and ejected of 280 km³ (67 cu mi) of material. This eruption, 1.3 million years BP, was preceded by the Huckleberry Ridge Tuff and succeeded by the Lava Creek Tuff, both of which were also formed by the Yellowstone hotspot.[2]

Mesa Falls eruption
Mesa Falls Tuff exposed at southern rim of both the Island Park Caldera and the Henry's Fork Caldera near Ashton, Idaho.
Volcano	Henry's Fork Caldera
Date	1.3 million years ago
Type	Ultra-Plinian
Location	Idaho, United States 44.33°N 111.33°W / 44.33; -111.33
Volume	280 km3 (67 cu mi)
VEI	7
Extent of the Mesa Falls ash bed