Idaho Falls, Idaho – A swarm of earthquakes shook eastern Idaho overnight into Monday morning, with at least five quakes above magnitude 3.0 striking near the Montana border. The strongest, a magnitude 3.9, hit just before 1 a.m. about 20 miles northwest of Spencer, less than 100 miles from Yellowstone National Park.
According to the U.S. Geological Survey, the cluster began shortly after midnight and continued into the morning, with quakes ranging from magnitude 2.6 to 3.9. All struck at shallow depths of around 10 kilometers, amplifying the shaking potential for nearby communities. No damage reports have been filed, but residents across Clark County and nearby areas may have felt light to moderate shaking.
The location of the swarm — roughly 74 miles from Yellowstone National Park — has drawn attention, given the region’s history of seismic activity linked to the Yellowstone supervolcano. While experts caution that earthquake swarms are common in the Intermountain West and do not necessarily signal larger eruptions, the proximity highlights the geologic volatility of the area.
Emergency officials advise residents to review earthquake safety plans, secure heavy household items, and remain alert for aftershocks. The USGS continues to monitor the swarm, with additional updates expected if seismic activity persists.
