Earthquake - Emergency Management

(Please see for the latest version of this information)

Home > Emergency Management > How-to Prepare Resources > Earthquake


Idaho is ranked fifth in the nation for earthquake risk, after California, Alaska, Nevada, and Utah. Two of the largest earthquakes in the last 70 years occurred in, or adjacent to Idaho. They were Hebgen Lake in 1959, which measured 7.5 on the Richter scale, and Mount Borah in 1983, which measured 7.3. The two major faults closest to Ada County are Squaw Butte, north of Emmett, and the recently discovered Water Tank fault, about 57 miles southeast of Boise.

Since 1988 all buildings in Idaho have been required to conform with the Uniform Building Code (UBC). This code establishes various earthquake risk zones and specifies construction features required for each zone to enhance earthquake resistance. Check out these earthquake-related links:

Amatrice on 24 Augusto 2016 after the earthquake