Earthquake · reviewed by a seismologist
M 2.3ml
Earthquake near Challis, ID
No earthquake was likely felt in Challis in the 24 hours to 2:40 pm MST (21:40 UTC). The last one was M 2.0, 9 km (6 mi) SSW, at 1:32 am MDT on 17 August 2026, estimated intensity II (weak) in town. Every earthquake near Challis
This page: a magnitude 2.3 earthquake was recorded 33 km (21 mi) south-southeast of Challis, ID, at 11:12 pm MDT on 30 September 2025 (05:12 UTC), 4.3 km deep.
USGS: 26 km E of Clayton, Idaho
- When
- 11:12 pm MDT on 30 September 2025 ()
- Where
- 33 km (21 mi) south-southeast of Challis, ID · earthquakes near Challis
- Idaho today
- every earthquake in Idaho in the last 24 hours
- Magnitude
- M 2.3 (ml)
- Depth
- 4.3 km below the surface
- Felt
- no reports yet
- Nearest
- Custer County, 15 km WNW
- Nearest mapped fault
- Lone Pine fault, 4 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 406 days ago
Earthquake alerts for Challis, ID
Get a notification in this browser when USGS records an earthquake near Challis, ID. 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 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 19 km (12 mi) from the epicentre. In Challis, 33 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.
How big was it?
This earthquake released about 72 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 210,000× the energy of this one
- Magna, Utah 2020 M 5.7 150,000× the energy of this one
- Around the size people start to feel M 3.0 13× the energy of this one
- This earthquake M 2.3 about 72 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 4.3 on 2025-06-08 — about 1,200 times the energy of this one.
Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1983 Borah Peak Earthquake, Idaho · 25 km SE of this epicentre
- 5.6 18 km ESE of Challis, Idaho · 27 km N of this epicentre
- 5.5 22 km E of Clayton, Idaho · 7 km NNW of this epicentre
- 5.4 29 km NW of Mackay, Idaho · 21 km SE of this epicentre
- 5.4 23 km E of Clayton, Idaho · 3 km W 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 44.2293, -114.0687. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Custer County, ID | 15 km (10 mi) | WNW | earthquakes near Custer County |
| Lemhi County, ID | 79 km (49 mi) | N | earthquakes near Lemhi County |
| Blaine County, ID | 93 km (58 mi) | S | earthquakes near Blaine County |
| Butte County, ID | 94 km (58 mi) | SE | earthquakes near Butte County |
| Camas County, ID | 99 km (61 mi) | SW | earthquakes near Camas County |
| Beaverhead County, MT | 137 km (85 mi) | NE | earthquakes near Beaverhead County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
12 earthquakes have been recorded within 50 km since this one.
- 2.6 25 km S of Clayton, Idaho
- 1.7 25 km SSE of Challis, Idaho
- 2.0 8 km SSW of Challis, Idaho
- 2.3 7 km E of Challis, Idaho
- 2.6 4 km NW of Challis, Idaho
- 2.4 2 km NW of Challis, Idaho
- 2.6 26 km S of Clayton, Idaho
- 1.7 14 km NNE of Challis, Idaho
- 2.4 29 km S of Clayton, Idaho
- 2.1 14 km W of Clayton, Idaho
- 1.7 2 km NE of Clayton, Idaho
- 1.8 9 km NW of Clayton, Idaho
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.