LITUYA BAY IS shaped like a T, with the tidal entrance at the bottom and Cenotaph Island halfway up the vertical stem. At the top of the T, to the right, is Crillon Inlet, which trends southeast for approximately a mile and a half. Gilbert Inlet runs to the left and terminates at the face of Lituya Glacier, which flows down the slopes of 12,700-foot Mount Crillon. Beyond Lituya Glacier lies Desolation Valley, which abuts Fairweather Glacier twelve miles farther north. Draw a line across Fairweather Glacier, down the middle of Desolation Valley, and along the Lituya T and you have mapped a small portion of the Fairweather Fault, where a great slab of the earth’s rocky skin known as the North American Plate (which underlies all of North America, Greenland, and parts of Siberia) grinds up against its eponymous counterpart, the Pacific Plate. The Fairweather Fault runs southeast for more than a hundred miles from up near Yakutat to Cape Spencer, where it links into a jagged system of cracks and fractures that reaches all the way through British Columbia, Washington, Oregon, and into California. The surfaces of the fault are vertical and the motion of the tectonic plates is horizontal, which in turn means that the pressure that inevitably builds up between the North American Plate and the Pacific Plate as the two circle each other like a pair of grappling sumo wrestlers must sooner or later be released in the form of a jarring earthquake. When Howard Ulrich, a fisherman from the village of Pelican, seventy miles to the south, entered Lituya Bay on the evening of July 9, 1958, aboard his thirty-eight-foot wooden troller, the Edrie, he had no idea the Fairweather Fault was about to strike.