Significant earthquakes of 2020

March 31, 2020 Earthquake: Custer County, Idaho, United States

March 31, 2020 · M6.5

A magnitude 6.5 earthquake struck Custer County, Idaho, United States on March 31, 2020 at 23:52:30 UTC, 12 km below the surface.

Map

Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.

The earthquake

Date
March 31, 2020
Time
23:52:30 UTC
Place
Custer County, Idaho, United States
Magnitude
6.5 (Mw)
Focal depth
12 km (7 mi)
Intensity
6 on the Modified Mercalli scale
Tsunami
None recorded
Epicenter
44.465° N, 115.118° W

The toll

Damage
Limited (under about $1 million)

Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.

What the record says

NCEI’s account, from the sources it cites.

Some damage to the Custer County courthouse and the Road and Bridge services building at Challis. Several avalanches and rockslides occurred on Highway 21 between Stanley and Lowman. A seiche was observed in a swimming pool in northern Utah.

Lowman, ID, US - CDI: 6; Stanley, ID, US - CDI: 6; Eden, ID, US - CDI: 6; Pollock, ID, US - CDI: 6; Dell, MT, US - CDI: 6

Other significant earthquakes nearby

Within 200 km, the deadliest first.

More

Significant earthquakes of 2020The 2000sEvery quake the USGS located in 2020Recent earthquakes near hereThis day in weather history

Sources

Significant earthquakes from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI earthquake 10967.