Twenty Years After the Borah Peak Earthquake—Field Guide to Surface-Faulting Earthquakes Along the Lost River Fault, Idaho

By Kathleen M. Haller and Anthony J. Crone
Following U.S. Highway 93 from Arco to Challis, Idaho, this trip focuses on the character of the historical rupture and the paleoseismic evidence for prehistoric events along this famous normal-fault system. Several stops are along the 34-km-long spectacular surface ruptures from the 1983 (M 7.3) Borah Peak earthquake. Stops north and south of the surface rupture explain the chronology of prehistoric earthquakes along the 140-km-long fault.
thumbnail image of Echelon surface rupture northwest of Borah Peak (fig. 2)