A series of earthquakes shook the Challis National Forest and surrounding areas of Idaho about 78 miles northeast of Boise on Tuesday evening. 

The largest of them, which was 6.5 on the Richter scale, was the strongest quake Idaho had seen since 1983, according to the U.S. Geological Survey website. The Richter scale is a way of measuring the strength of an earthquake.

A 6.5 earthquake on the scale is “strong” and the world sees about 120 per year, according to the USGS. A 6 on the scale is 10 times stronger than a 5, because the force of a quake at a given point on the scale is 10 times more powerful than one at the previous point.

Beginning around 5:52 p.m. with the 6.5 magnitude quake, the strongest shocks were felt in a 15-mile radius around Shake Creek and Laidlow Creek in the Salmon River Mountains.

The farthest shockwaves recorded reached as far north as Pullman and Albion, according to a USGS interactive map. Others traveled as far as the northern edge of Nevada, north Utah, eastern Oregon and southern Montana.

This story will be updated as more information becomes available.