Earthquakes in Broadwater County, Montana
The most recent earthquake of M2.5 or more near Broadwater County was M 2.7, 3 km ENE of Helena, Montana, 49 km (30 mi) NW of the centre of Broadwater County, at 3:38 pm MDT on 9 March 2025, 5 km deep. 267 people reported feeling it to USGS. The estimated shaking at the centre of Broadwater County was intensity II (weak), felt by some people at rest indoors. 57 smaller earthquakes have been recorded near Broadwater County since.
No earthquake of M1.5 or more was recorded within 50 km (31 mi) of the centre of Broadwater County in the last 24 hours.
- Last 24 hours
- 0
- Last 7 days
- 1
- Last 30 days
- 6 · an average 30 days here since 2016: 2.9
- Last 12 months
- 19 · largest M 2.4 on 20 May 2026
- Since 2016
- 389 earthquakes of M1.5 or more
- Largest since 2016
- M 4.2 on 15 August 2019, 4 km NW of Manhattan, Montana
Latest quake, 24 hours and 7 days: the QuakeIndex database, which reads USGS every 30 seconds, read at ; 30 days and 12 months: the QuakeIndex catalogue, counted to · earthquakes of M1.5 or more within 50 km (31 mi) of the centre of Broadwater County · shaking is estimated for the centre with the intensity equation USGS Did You Feel It? uses
Every earthquake in Montana in the last 24 hours →
Quiet QuakeIndex 0 / 100
0 quakes of M1.5 or larger in the last 7 days within 50 km. Normal for here is 0 to 1 in a week.
Compared against Broadwater County, Montana's own 10 years · USGS catalogue · updated
If you felt one
- Was that an earthquake? — checks what was recorded near you in the last hour
- Report what you felt to USGS — reports go to USGS, not to us, and they are what produces the intensity maps
- Expect aftershocks, and be ready to Drop, Cover, and Hold On if you feel one; if you are in a damaged building, go outside and move away from it (Ready.gov, FEMA; what to do during and after an earthquake)
QuakeIndex does not issue warnings or forecasts. For earthquake early warning see ShakeAlert and the MyShake app.
The last 30 days
Show these earthquakes on your own site: a free card with this strip and the latest quakes near Broadwater County, Montana, for a local news site, school or neighborhood page.
Live · last 7 days
Latest earthquakes within 50 km
None within 50 km in the latest snapshot we hold; the full 7 days load from USGS as this page opens.
Source USGS · snapshot of
The last 7 days on the map
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The centre is 46.330, -111.498, the Census internal point of Broadwater County, Montana from the US Census Bureau Gazetteer (2024). Activity on this page is measured within 50 km of it — the dashed circle.
Largest on record nearby
The strongest shaking this record implies at the centre of Broadwater County, Montana is intensity III (weak), from the M 4.2 of 2019, 50 km away. At that level a few people indoors notice it; most do not.
| Magnitude | When | Where | Shaking here (est.) |
|---|---|---|---|
| M 4.2 | 4 km NW of Manhattan, Montana · felt by 445 | III · Weak | |
| M 4.0 | 11 km NNE of Manhattan, Montana · felt by 650 | III · Weak | |
| M 3.7 | 4 km N of Manhattan, Montana · felt by 570 | II · Weak | |
| M 3.7 | 5 km NW of Clancy, Montana | II · Weak | |
| M 3.3 | 4 km W of Ponderosa Pines, Montana · felt by 6 | II · Weak | |
| M 3.1 | 6 km NNW of Three Forks, Montana · felt by 21 | II · Weak | |
| M 2.9 | 6 km S of Ponderosa Pines, Montana · felt by 9 | II · Weak | |
| M 2.9 | 11 km SW of Winston, Montana · felt by 4 | II · Weak |
From the QuakeIndex catalogue, built from the USGS FDSN event service · within 50 km of the centre above. Shaking is an estimate for the centre from magnitude, depth and distance, with the intensity equation USGS Did You Feel It? uses (Atkinson & Wald, 2007), on the Modified Mercalli scale. Ground conditions change it locally; it is a description of the past, not a hazard rating.
Before 2016
The USGS record from 1900 to 2015 lists 10 earthquakes of M5 or more within 50 km of the centre of Broadwater County, Montana; the 8 largest:
- 6.6 The 1925 Clarkston Valley, Montana Earthquake · 28 km S of the centre
- 6.4 Clarkston Valley, Montana (Aftershock) · 28 km S of the centre
- 6.1 The 1935 Helena, Montana Earthquakes (Mainshock) · 31 km NNW of the centre
- 5.9 2 km ENE of Helena, Montana · 49 km NW of the centre
- 5.9 The 1935 Helena, Montana Earthquakes (Largest Aftershock) · 36 km NW of the centre
- 5.5 Clarkston Valley, Montana (Aftershock) · 28 km S of the centre
- 5.5 Clarkston Valley, Montana (Aftershock) · 28 km S of the centre
- 5.5 Clarkston Valley, Montana (Aftershock) · 28 km S of the centre
USGS ComCat, M5+ from 1900 to 2015. Epicentres of early earthquakes are estimates. This is the record, not a forecast.
Town pages near Broadwater County, Montana
Townsend 2 km · 5 M2.5+ named after it · Three Forks 49 km · 5 M2.5+ named after it · Boulder 49 km · 5 M2.5+ named after it
Each town page lists every M1.5+ earthquake within 30 km since 2016 and the ones USGS named after it. Town names: GeoNames (CC BY 4.0).
Be ready
Earthquakes cannot be predicted, here or anywhere, so the useful step is the one taken beforehand. The advice below is from the agencies responsible for it.
- Ready.gov: earthquakes (FEMA) — what to do before, during and after, including Drop, Cover, and Hold On
- Build a kit (FEMA) — water, food and supplies for several days; our summary
- USGS: preparedness — the hazard behind the advice, from the agency that records every quake on this page
- The Great ShakeOut — the yearly earthquake drill, with material for homes, schools and workplaces