M1.6 earthquake 47 km SE of Mammoth, Wyoming

A magnitude 1.6 earthquake struck 47 km SE of Mammoth, Wyoming on Fri, Dec 29, 2017, 8:47 PM MST (03:47 UTC), 3 km (2 mi) below the surface.

A larger quake followed: M3.1 12 km NE of West Yellowstone, Montana. This one was a foreshock.

Map

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

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: at least 200 in the 60 days after this one and 11 in the 30 days before it.

The first 60 of at least 200.

From the USGS Earthquake Hazards Program and its partner networks, event uu60263477. Read Fri, Oct 2, 2026, 8:11 AM UTC.