Washington Earthquake's Mysterious Source DiscoveredGeologists have finally solved a 142-year-old earthquake mystery in central Washington state. Until now, no one knew the source of a powerful earthquake that rattled windows from Washington to Montana on Dec. 14, 1872. The quake’s size, based on historical accounts, was magnitude 6.8. At the time, newspapers put the epicenter in several areas, from underneath the Puget Sound north to Vancouver, British Columbia. But Washington’s eyewitness reports, slower to arrive in the sparsely populated state, centered the most intense damage east of the Cascades, near Wenatchee, where a giant landslide temporarily dammed the Columbia River. FULL REPORT