Active Faults

This dataset contains information on faults and associated folds in Idaho that demonstrate geological evidence of coseismic surface deformation in large earthquakes during the past 1.6 million years (Myr). At the time the USGS Quaternary Fault and Fold database was established (1993), the Quaternary time period was defined as <1.6 Myr in the 1983 Geologic Time Scale, published in 1983. In 1999, it was updated to 1.8 Myr, and in 2009 it was revised to 2.6 Myr. Most recently, in 2018 it was revised again to 2.58 Myr. Data source: U.S. Geological Survey and Idaho Geological Survey, Quaternary fault and fold database for the United States, accessed May 30, 2023, at: https://www.usgs.gov/natural-hazards/earthquake-hazards/faults.