Wasatch Fault

The Wasatch Fault is an active normal fault running about 390 kilometers along the western edge of the Wasatch Mountains from southern Idaho through northern Utah, forming the eastern boundary of the Basin and Range geologic province and the structure that has uplifted and tilted the Wasatch Mountains themselves. The fault is made up of ten segments, five of which remain active today, and it has slipped at an average rate of 0.8 to 1.2 millimeters a year over its geological history, with individual segments capable of producing earthquakes up to magnitude 7.5; researchers estimate that a magnitude 7.0 or larger quake strikes any given central segment roughly every 900 to 1,300 years. About 80 percent of Utah's population lives along the Wasatch Front the fault helped build, making it the largest single earthquake hazard in the interior western United States, and the fault produced a magnitude 5.7 earthquake near Magna, Utah, in March 2020.