QuakeIndex

Earthquake · reviewed by a seismologist

M 1.1ml

Earthquake near West Yellowstone, MT

USGS: 7 km ENE of Hebgen Lake Estates, Montana

2:58 am MDT, Sep 30, 2026 · · 8.3 km deep · released about 1.6 lb of TNT

10 km30 km60 km120 km N Fremont County 70 kmGallatin County 81 kmMadison County 87 kmPark County 87 kmTeton County 98 kmClark County 114 kmTeton County 115 kmMadison County 120 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
2:58 am MDT on 30 September 2026 ()
Where
14 km (9 mi) N of West Yellowstone, MT · earthquakes near West Yellowstone
Magnitude
M 1.1 (ml)
Depth
8.3 km below the surface
Felt
no reports yet
Nearest
Fremont County, 70 km SSW
Nearest mapped fault
Red Canyon fault, under 1 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 3 days ago

A magnitude 1.1 earthquake was recorded 14 km (9 mi) N of West Yellowstone, MT, at 2:58 am MDT on 30 September 2026 (08:58 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 1.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 9,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 6,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 600× the energy of this one
  4. This earthquake M 1.1 about 1.6 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 65,000 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.2 The 1959 Hebgen Lake, Montana Earthquake · 8 km W of this epicentre
  2. 6.5 14 km N of Madison Junction, Wyoming · 17 km E of this epicentre
  3. 6.3 22 km SW of Mammoth, Wyoming · 19 km E of this epicentre
  4. 6.1 30 km SSW of Big Sky, Montana · 46 km NW of this epicentre
  5. 6.0 21 km E of West Yellowstone, Montana · 26 km SE 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 44.7892, -111.1047. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fremont County, ID 70 km (44 mi) SSW earthquakes near Fremont County
Gallatin County, MT 81 km (50 mi) N earthquakes near Gallatin County
Madison County, MT 87 km (54 mi) NW earthquakes near Madison County
Park County, MT 87 km (54 mi) NNE earthquakes near Park County
Teton County, WY 98 km (61 mi) SSE earthquakes near Teton County
Clark County, ID 114 km (71 mi) WSW earthquakes near Clark County

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

Aftershocks so far

1 earthquake has been recorded within 50 km since this one.

  1. 0.8 25 km SSE of West Yellowstone, Montana

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.