An earthquake struck north of Boise Tuesday evening, with people across a large area reporting shaking.
The U.S. Geological Survey reports the magnitude 6.5 temblor struck just before 5 p.m. It was centred 73 miles (118 kilometres) northeast of Meridian, near the rural mountain town of Stanley. There were no immediate reports of damage or injuries.
More than 2 million live in the region that could feel the Idaho quake, according to the USGS, with reports of shaking coming in from as far away as Helena, Montana, and Salt Lake City, Utah.
Dr. Lucy Jones, a seismologist at Caltech and the founder of the Dr. Lucy Jones Center for Science and Seismology, said the Idaho region has an earthquake of about this size every 30 or 40 years. The most recent one, a magnitude 7.0 earthquake near Borah Peak in 1983, killed two children in Challis and caused an estimated $12.5 million in property damage across Challis and Mackay.
That quake was along what scientists call a "normal fault," with the quake causing vertical movement, she said. Tuesday's quake appeared to be on an unmapped "strike-slip fault," causing mostly horizontal movement along the fault line.
"This is one that wasn't obvious enough to be mapped before now," Jones said.
Residents in the region will likely continue to feel aftershocks, she said. The area had already recorded five aftershocks within the first hours after the 6.5 earthquake.
--with files from CTV News--