Earthquake · reviewed by a seismologist
M 3.2ml
Earthquake near Helena Valley West Central, MT
No earthquake was likely felt in Helena Valley West Central in the 24 hours to 9:08 am MST (16:08 UTC). The last one was M 1.5, 4 km (2 mi) SE, at 3:20 pm MDT on 18 May 2025, estimated intensity II (weak) in town. Every earthquake near Helena Valley West Central
This page: a magnitude 3.2 earthquake was recorded 48 km (30 mi) west of Helena Valley West Central, MT, at 11:22 am MST on 9 December 2025 (18:22 UTC), 12 km deep. 1 person has reported feeling it to USGS.
USGS: 12 km NNW of Avon, Montana
- When
- 11:22 am MST on 9 December 2025 ()
- Where
- 48 km (30 mi) west of Helena Valley West Central, MT · earthquakes near Helena Valley West Central
- Montana today
- every earthquake in Montana in the last 24 hours
- Magnitude
- M 3.2 (ml)
- Depth
- 12 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- Powell County, 25 km NW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 252 days ago
Earthquake alerts for Helena Valley West Central, MT
Get a notification in this browser when USGS records an earthquake near Helena Valley West Central, MT. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 45 km (28 mi) from the epicentre. In Helena Valley West Central, 48 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: Lincoln 30 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 180,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
- Magna, Utah 2020 M 5.7 5,600× the energy of this one
- This earthquake M 3.2 about 1,900 lb of TNT
- Around the size people start to feel M 3.0 this one released 2× more
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 5.8 on 2017-07-06 — about 7,900 times the energy of this one.
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 46.6877, -112.6895. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Powell County, MT | 25 km (16 mi) | NW | earthquakes near Powell County |
| Lewis and Clark County, MT | 54 km (33 mi) | NNE | earthquakes near Lewis and Clark County |
| Granite County, MT | 65 km (40 mi) | WSW | earthquakes near Granite County |
| Deer Lodge County, MT | 75 km (46 mi) | SSW | earthquakes near Deer Lodge County |
| Jefferson County, MT | 79 km (49 mi) | SE | earthquakes near Jefferson County |
| Silver Bow County, MT | 88 km (55 mi) | S | earthquakes near Silver Bow County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
28 earthquakes have been recorded within 50 km since this one.
- 1.2 14 km SE of Lincoln, Montana
- 0.8 10 km NW of Helena Valley Northwest, Montana
- 1.1 14 km NNE of Marysville, Montana
- 1.3 20 km NNE of Marysville, Montana
- 1.0 15 km SE of Lincoln, Montana
- 1.7 14 km ESE of Lincoln, Montana
- 1.4 5 km WSW of Elliston, Montana
- 2.1 6 km WSW of Elliston, Montana
- 1.2 17 km WNW of Lincoln, Montana
- 0.9 12 km ESE of Lincoln, Montana
- 1.3 14 km ESE of Lincoln, Montana
- 1.2 14 km ESE of Lincoln, Montana
- 1.6 11 km ESE of Lincoln, Montana
- 1.7 8 km S of Marysville, Montana
- 1.7 13 km SE 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.