This tranquil scene at Cedar Creek along the west flank of the Lost River Range in southern Idaho belies the severe ground shaking caused by the magnitude 7.3 earthquake. Idaho Earthquake October 28, 1983.

Idaho Earthquake October 28, 1983. This tranquil scene at Cedar Creek along the west flank of the Lost River Range in southern Idaho belies the severe ground shaking caused by the magnitude 7.3 earthquake. Visible on the left are the terraced scarps and troughs (graben) formed by the ground breakage. Photo by R.E. Wallace, 1983. Cover, Earthquake Information Bulletin, v.16, no.1.