QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

Earthquake near Star Valley Ranch, WY

No earthquake was likely felt in Star Valley Ranch in the 24 hours to 3:55 pm MST (22:55 UTC). The last one was M 3.8, 75 km (47 mi) SSW, at 5:05 am MDT on 15 May 2026, estimated intensity II (weak) in town; 29 felt reports to USGS. Every earthquake near Star Valley Ranch

This page: a magnitude 2.7 earthquake was recorded 16 km (10 mi) north-northwest of Star Valley Ranch, WY, at 12:38 am MDT on 30 June 2021 (06:38 UTC), 5.0 km deep. 15 people have reported feeling it to USGS.

USGS: 6 km S of Alpine, Wyoming

12:38 am MDT, Jun 30, 2021 · · 5.0 km deep · released about 340 lb of TNT

10 km30 km60 km120 km N Caribou County 55 kmBonneville County 58 kmTeton County 75 kmMadison County 92 kmBear Lake County 94 kmSublette County 97 kmLincoln County 101 kmBannock County 109 kmBingham County 113 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
12:38 am MDT on 30 June 2021 ()
Where
16 km (10 mi) north-northwest of Star Valley Ranch, WY · earthquakes near Star Valley Ranch
Magnitude
M 2.7 (ml)
Depth
5.0 km below the surface
Felt
15 reports · strongest reported intensity IV
Nearest
Caribou County, 55 km SW
Nearest mapped fault
Grand Valley fault, 2 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 1889 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 24 km (15 mi) from the epicentre. In Star Valley Ranch, 16 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.

Likely felt in: Star Valley Ranch 16 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 5.8 4 km SSE of Auburn, Wyoming · 38 km S of this epicentre
  2. 5.3 Southeastern Idaho · 26 km WSW of this epicentre
  3. 5.3 29 km WSW of Freedom, Idaho · 36 km WSW 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 43.1047, -111.0202. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Caribou County, ID 55 km (34 mi) SW earthquakes near Caribou County
Bonneville County, ID 58 km (36 mi) WNW earthquakes near Bonneville County
Teton County, ID 75 km (46 mi) NNW earthquakes near Teton County
Madison County, ID 92 km (57 mi) NW earthquakes near Madison County
Bear Lake County, ID 94 km (59 mi) SSW earthquakes near Bear Lake County
Sublette County, WY 97 km (60 mi) ESE earthquakes near Sublette County

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

Aftershocks so far

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

  1. 2.3 11 km NE of Star Valley Ranch, Wyoming
  2. 2.3 15 km E of Afton, Wyoming
  3. 2.1 27 km SSW of Irwin, Idaho
  4. 3.3 10 km W of Hoback, Wyoming
  5. 2.8 7 km WSW of Hoback, Wyoming
  6. 2.4 17 km W of Fairview, Wyoming
  7. 1.9 15 km W of Freedom, Idaho
  8. 3.3 13 km W of Freedom, Idaho
  9. 2.8 13 km W of Freedom, Idaho
  10. 2.3 12 km W of Fairview, Wyoming
  11. 1.6 12 km WNW of Fairview, Wyoming
  12. 2.4 6 km W of Hoback, Wyoming
  13. 1.7 4 km ENE of Hoback, Wyoming
  14. 1.8 6 km ENE of Hoback, Wyoming
  15. 1.7 14 km E of Irwin, Idaho

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.