QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Deer Lodge, MT

No earthquake was likely felt in Deer Lodge in the 24 hours to 7:54 am MST (14:54 UTC). The last one was M 3.2, 33 km (20 mi) N, at 11:22 am MST on 9 December 2025, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Deer Lodge

This page: a magnitude 1.8 earthquake was recorded 49 km (31 mi) northwest of Deer Lodge, MT, at 11:59 am MDT on 30 June 2021 (17:59 UTC), 6.7 km deep.

USGS: 6 km W of Drummond, Montana

11:59 am MDT, Jun 30, 2021 · · 6.7 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N Powell County 30 kmGranite County 34 kmMissoula County 64 kmDeer Lodge County 65 kmLewis and Clark County 82 kmRavalli County 94 kmSilver Bow County 97 kmJefferson County 109 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
11:59 am MDT on 30 June 2021 ()
Where
49 km (31 mi) northwest of Deer Lodge, MT · earthquakes near Deer Lodge
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.8 (ml)
Depth
6.7 km below the surface
Felt
no reports yet
Nearest
Powell County, 30 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1962 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 Deer Lodge, 49 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 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 since 1900 lists no earthquake of M5 or more within 50 km.

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 46.6722, -113.2315. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Powell County, MT 30 km (19 mi) NE earthquakes near Powell County
Granite County, MT 34 km (21 mi) SSW earthquakes near Granite County
Missoula County, MT 64 km (40 mi) NW earthquakes near Missoula County
Deer Lodge County, MT 65 km (40 mi) S earthquakes near Deer Lodge County
Lewis and Clark County, MT 82 km (51 mi) NE earthquakes near Lewis and Clark County
Ravalli County, MT 94 km (59 mi) SW earthquakes near Ravalli County

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

Aftershocks so far

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

  1. 1.5 7 km NNW of Ovando, Montana
  2. 1.2 22 km SW of Ovando, Montana
  3. 1.2 17 km WNW of Lincoln, Montana
  4. 3.1 5 km NW of Ovando, Montana
  5. 1.7 16 km W of Lincoln, Montana
  6. 3.2 12 km NNW of Avon, Montana
  7. 1.6 12 km N of Garrison, Montana
  8. 2.9 22 km WSW of Ovando, Montana
  9. 2.3 17 km S of Lincoln, Montana
  10. 2.1 17 km S of Lincoln, Montana
  11. 2.4 10 km S of Ovando, Montana
  12. 1.8 17 km ENE of Drummond, Montana
  13. 2.3 16 km ENE of Drummond, Montana
  14. 1.9 7 km WSW of Drummond, Montana
  15. 1.6 15 km WNW of Lincoln, 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.