QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near West Yellowstone, MT

No earthquake was likely felt in West Yellowstone in the 24 hours to 9:49 am MST (16:49 UTC). The last one was M 2.8, 11 km (7 mi) NNW, at 1:21 am MDT on 8 September 2026, estimated intensity II (weak) in town. Every earthquake near West Yellowstone

This page: a magnitude 1.8 earthquake was recorded 34 km (21 mi) east-northeast of West Yellowstone, MT, at 1:54 am MDT on 3 July 2021 (07:54 UTC), 3.9 km deep.

USGS: 27 km S of Mammoth, Wyoming

1:54 am MDT, Jul 3, 2021 · · 3.9 km deep · released about 17 lb of TNT

Every earthquake near West Yellowstone Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Teton County 78 kmPark County 83 kmFremont County 85 kmPark County 90 kmGallatin County 96 kmTeton County 115 kmMadison County 117 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
1:54 am MDT on 3 July 2021 ()
Where
34 km (21 mi) east-northeast of West Yellowstone, MT · earthquakes near West Yellowstone
Magnitude
M 1.8 (ml)
Depth
3.9 km below the surface
Felt
no reports yet
Nearest
Teton County, 78 km SSE
Nearest mapped fault
Red Canyon fault, 25 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1870 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 13 km (8 mi) from the epicentre. In West Yellowstone, 34 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

The largest earthquake within 50 km since 2016 was M 4.4 on 2017-06-16 — about 6,000 times the energy of this one.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.2 The 1959 Hebgen Lake, Montana Earthquake · 41 km W of this epicentre
  2. 6.5 14 km N of Madison Junction, Wyoming · 17 km WNW of this epicentre
  3. 6.3 22 km SW of Mammoth, Wyoming · 17 km NW of this epicentre
  4. 6.0 21 km E of West Yellowstone, Montana · 15 km SW of this epicentre
  5. 5.9 26 km SSE of Mammoth, Wyoming · 7 km ENE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 44.7273, -110.6882. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Teton County, WY 78 km (49 mi) SSE earthquakes near Teton County
Park County, MT 83 km (51 mi) N earthquakes near Park County
Fremont County, ID 85 km (53 mi) SW earthquakes near Fremont County
Park County, WY 90 km (56 mi) ESE earthquakes near Park County
Gallatin County, MT 96 km (59 mi) NNW earthquakes near Gallatin County
Teton County, ID 115 km (72 mi) SSW earthquakes near Teton County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

60 earthquakes have been recorded within 50 km since this one.

  1. 2.2 63 km ESE of West Yellowstone, Montana
  2. 2.5 63 km ESE of West Yellowstone, Montana
  3. 1.7 64 km ESE of West Yellowstone, Montana
  4. 2.2 64 km ESE of West Yellowstone, Montana
  5. 1.5 62 km ESE of West Yellowstone, Montana
  6. 1.6 63 km ESE of West Yellowstone, Montana
  7. 1.6 62 km ESE of West Yellowstone, Montana
  8. 1.8 63 km ESE of West Yellowstone, Montana
  9. 2.0 64 km ESE of West Yellowstone, Montana
  10. 1.6 63 km ESE of West Yellowstone, Montana
  11. 1.7 64 km ESE of West Yellowstone, Montana
  12. 2.4 65 km ESE of West Yellowstone, Montana
  13. 2.0 64 km ESE of West Yellowstone, Montana
  14. 1.5 63 km ESE of West Yellowstone, Montana
  15. 1.6 65 km SSE of Mammoth, Wyoming

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.