Montana earthquakes

M4.9 earthquake 24 km SSW of Mammoth, Wyoming

A magnitude 4.9 earthquake struck 24 km SSW of Mammoth, Wyoming on Sun, Dec 19, 1976, 10:10 AM MST (17:10 UTC), 5 km (3 mi) below the surface.

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

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The earthquake

Magnitude
4.9 (mb), light
Local time
UTC
1976-12-19 17:10:15 UTC
Depth
5.0 km (3.1 mi), shallow
Epicenter
44.772° N, 110.800° W
Region
Montana
Tsunami flag
No
Status
Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Stations used
33

Nearest places

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

Nearby

Within 100 km, magnitude 1.9 and up: 3 in the 60 days after this one and 10 in the 30 days before it.

After

  1. 4.417 km SSW of Mammoth, Wyoming · 18174 days ago · 5 km deep · 8 km away
  2. 3.318 km S of West Yellowstone, Montana · 18173 days ago · 9 km deep · 37 km away
  3. 3.223 km WSW of Hebgen Lake Estates, Montana · 18118 days ago · 5 km deep · 53 km away

Before

  1. 3.04 km ESE of West Yellowstone, Montana · 18178 days ago · 5 km deep · 25 km away
  2. 3.15 km ENE of West Yellowstone, Montana · 18182 days ago · 5 km deep · 22 km away
  3. 4.524 km SSW of Mammoth, Wyoming · 18184 days ago · 5 km deep · 0 km away
  4. 4.923 km SSW of Mammoth, Wyoming · 18184 days ago · 6 km deep · 1 km away
  5. 3.510 km NNE of West Yellowstone, Montana · 18185 days ago · 5 km deep · 20 km away
  6. 5.525 km SSW of Mammoth, Wyoming · 18185 days ago · 5 km deep · 1 km away
  7. 3.431 km ENE of Spencer, Idaho · 18192 days ago · 5 km deep · 87 km away
  8. 3.619 km ENE of Hebgen Lake Estates, Montana · 18196 days ago · 5 km deep · 16 km away
  9. 3.522 km E of West Yellowstone, Montana · 18197 days ago · 5 km deep · 13 km away
  10. 3.33 km SW of West Yellowstone, Montana · 18197 days ago · 9 km deep · 31 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp0000kub (also filed as ushis3424). Read Tue, Sep 22, 2026, 9:01 PM UTC.