Horrible Today: Live Footage of Massive Eruption of Yellowstone Volcano That Threatened Many Lives

The Yellowstone Caldera is the latest in a series of volcanic structures stretching across the Snake River Plain in Idaho and into northern Nevada. One of the oldest volcanic complexes in the chain, the McDermitt caldera on the Nevada-Oregon border, has many similarities to Yellowstone.
The Yellowstone hotspot has been around for a long time, perhaps more than 50 million years. It appears that this earthquake started off the coast of northern California, and the movement of the North American plate resulted in volcanism that trended across northern and northeastern California and into northern Nevada. Tectonic movements spread these volcanic products northward, and they are now found in coastal areas of Oregon and Washington.
About 20-22 million years ago the hot spot diminished, perhaps because the rise of magma to the surface was blocked by a plate of cold oceanic crust that was replaced by the North American continent. Magma built up beneath the slab and finally broke open nearly 17 million years ago with the Columbia River Basalt eruption-a massive outpouring of molten basaltic lava that occurred along Idaho's borders with Washington and Oregon and sent lava flowing everywhere. road to the Pacific Ocean.