QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Dillon, MT

No earthquake was likely felt in Dillon in the 24 hours to 1:23 pm MST (20:23 UTC). The last one was M 2.0, 14 km (9 mi) N, at 2:45 pm MDT on 7 May 2026, estimated intensity II (weak) in town. Every earthquake near Dillon

This page: a magnitude 1.8 earthquake was recorded 40 km (25 mi) northeast of Dillon, MT, at 3:37 pm MST on 3 March 2020 (22:37 UTC), 4.0 km deep.

USGS: 5 km W of Sheridan, Montana

3:37 pm MST, Mar 3, 2020 · · 4.0 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Madison County 31 kmSilver Bow County 58 kmBeaverhead County 61 kmJefferson County 76 kmGallatin County 86 kmDeer Lodge County 98 kmBroadwater 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
3:37 pm MST on 3 March 2020 ()
Where
40 km (25 mi) northeast of Dillon, MT · earthquakes near Dillon
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.8 (ml)
Depth
4.0 km below the surface
Felt
no reports yet
Nearest
Madison County, 31 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2444 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 12 km (7 mi) from the epicentre. In Dillon, 40 km away, the estimate is intensity I (not felt). 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 13 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 4.0 on 2016-09-03 — about 2,600 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.6 16 km N of Dillon, Montana · 29 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 45.4595, -112.2633. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Madison County, MT 31 km (19 mi) ESE earthquakes near Madison County
Silver Bow County, MT 58 km (36 mi) NNW earthquakes near Silver Bow County
Beaverhead County, MT 61 km (38 mi) SW earthquakes near Beaverhead County
Jefferson County, MT 76 km (47 mi) NNE earthquakes near Jefferson County
Gallatin County, MT 86 km (53 mi) E earthquakes near Gallatin County
Deer Lodge County, MT 98 km (61 mi) NW earthquakes near Deer Lodge County

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

Aftershocks so far

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

  1. 1.6 17 km ESE of Dillon, Montana
  2. 1.5 16 km E of Dillon, Montana
  3. 1.6 17 km ESE of Dillon, Montana
  4. 2.0 3 km W of Pony, Montana
  5. 1.5 19 km N of Dillon, Montana
  6. 1.9 12 km NNW of Ennis, Montana
  7. 2.2 12 km NNW of Ennis, Montana
  8. 1.6 18 km NNE of Dillon, Montana
  9. 1.8 2 km N of Pony, Montana
  10. 1.7 18 km NNE of Dillon, Montana
  11. 2.3 17 km N of Dillon, Montana
  12. 1.6 17 km W of Pony, Montana
  13. 1.5 7 km WSW of Ennis, Montana
  14. 1.6 13 km NNW of Ennis, Montana
  15. 2.1 13 km NNW of Ennis, 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.