M3.9 earthquake 11 km SSE of Challis, Idaho

A magnitude 3.9 earthquake struck 11 km SSE of Challis, Idaho on Tue, Dec 23, 2014, 4:56 AM MST (11:56 UTC), 7 km (4 mi) below the surface.

A larger quake followed: M5.0 9 km E of Challis, Idaho. This one was a foreshock.

Map

Where this earthquake was located, with the others nearby. Select one for its page.

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
3.9	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed
3.3	Mc	Montana Bureau of Mines and Geology	Preliminary · ±0.5 · 3 stations

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

1 person reported to the USGS what they felt; the strongest reported shaking was II, weak shaking.

Reviewed by a seismologist.

Distance and direction from each place to the epicenter, with its forecast.

Within 100 km, magnitude 1.5 and up: 111 in the 60 days after this one and 7 in the 30 days before it.

The first 60 of 111.

From the USGS Earthquake Hazards Program and its partner networks, event usc000td7c (also filed as mb14647871). Read Thu, Oct 1, 2026, 8:54 AM UTC.