Earthquake · reviewed by a seismologist
M 2.3ml
Earthquake near Challis, ID
No earthquake was likely felt in Challis in the 24 hours to 3:55 pm MST (22:55 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 19 km (12 mi) north-northeast of Challis, ID, at 8:55 am MDT on 29 March 2026 (14:55 UTC), 3.7 km deep.
USGS: 19 km NNE of Challis, Idaho
- When
- 8:55 am MDT on 29 March 2026 ()
- Where
- 19 km (12 mi) north-northeast of Challis, ID · earthquakes near Challis
- Idaho today
- every earthquake in Idaho in the last 24 hours
- Magnitude
- M 2.3 (ml)
- Depth
- 3.7 km below the surface
- Felt
- no reports yet
- Nearest
- Lemhi County, 36 km NE
- Nearest mapped fault
- Lost River fault, 10 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 224 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 20 km (12 mi) from the epicentre. In Challis, 19 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: Challis 19 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 98 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 5.8 150,000× the energy of this one
- Magna, Utah 2020 M 5.7 110,000× the energy of this one
- Around the size people start to feel M 3.0 9.8× the energy of this one
- This earthquake M 2.3 about 98 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 870 times the energy of this one.
Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:
- 5.6 18 km ESE of Challis, Idaho · 26 km SSE of this epicentre
- 5.5 22 km E of Clayton, Idaho · 44 km S of this epicentre
- 5.4 23 km E of Clayton, Idaho · 49 km S of this epicentre
- 5.1 9 km SE of Challis, Idaho · 26 km S of this epicentre
- 5.0 9 km E of Challis, Idaho · 19 km SSE 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 44.6737, -114.1700. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lemhi County, ID | 36 km (22 mi) | NE | earthquakes near Lemhi County |
| Custer County, ID | 45 km (28 mi) | S | earthquakes near Custer County |
| Beaverhead County, MT | 113 km (70 mi) | ENE | earthquakes near Beaverhead County |
| Valley County, ID | 116 km (72 mi) | W | earthquakes near Valley County |
| Butte County, ID | 135 km (84 mi) | SE | earthquakes near Butte County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
8 earthquakes have been recorded within 50 km since this one.
- 2.5 30 km SW of Salmon, Idaho
- 1.7 25 km SSE of Challis, Idaho
- 2.0 8 km SSW of Challis, Idaho
- 1.6 52 km NNW 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
- 1.7 14 km NNE of Challis, 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.