The 1959 Yellowstone Earthquake

At 11:37 p.m. on August 17, 1959, a magnitude 7.5 earthquake rocked Montana's Yellowstone country. In an instant, an entire mountainside fractured and thundered down onto the sites of unsuspecting campers. The mammoth avalanche generated hurricane-force winds ahead of it that ripped clothing from backs and heaved tidal waves in both directions of the Madison River Canyon. More than two hundred vacationers trapped in the canyon feared the dam upstream would burst. As debris and flooding over...