Montana earthquakes

M2.9 earthquake 25 km ESE of Mammoth, Wyoming

A magnitude 2.9 earthquake struck 25 km ESE of Mammoth, Wyoming on Tue, Sep 11, 2018, 7:30 AM MDT (13:30 UTC), 11 km (7 mi) below the surface.

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Map

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

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The earthquake

Magnitude
2.9 (ML, local (Richter)), micro
Magnitude from
University of Utah Seismograph Stations
Local time
UTC
2018-09-11 13:30:53 UTC
Depth
10.7 km (6.6 mi), shallow
Epicenter
44.861° N, 110.429° W
Region
Montana
Tsunami flag
No
Status
Reviewed by a seismologist

Magnitude estimates

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.ScaleComputed byNotes
2.85ML, local (Richter)University of Utah Seismograph StationsPreferred · Final · ±0.411 · 7 stations
2.9ML, local (Richter)USGS National Earthquake Information CenterReviewed · ±0.411 · 7 stations

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty
About 0.5 km horizontally, 0.7 km in depth
Magnitude uncertainty
±0.41
Depth from
From location
Station coverage gap
81°
Stations used
30

Nearest places

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

Nearby

Within 100 km, magnitude 1.5 and up: 32 in the 60 days after this one and 17 in the 30 days before it.

After

Before

Earthquakes todayMontana earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event uu60296242 (also filed as us2000hclt). Read Sat, Oct 3, 2026, 7:58 PM UTC.