QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4ml

Earthquake near Challis, ID

No earthquake was likely felt in Challis in the 24 hours to 2:46 pm MST (21:46 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 2.4 earthquake was recorded 2 km (2 mi) northwest of Challis, ID, at 11:51 pm MDT on 19 May 2026 (05:51 UTC), 5.4 km deep. 2 people have reported feeling it to USGS.

USGS: 2 km NW of Challis, Idaho

11:51 pm MDT, May 19, 2026 · · 5.4 km deep · released about 120 lb of TNT

10 km30 km60 km120 km N Custer County 28 kmLemhi County 54 kmValley County 114 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
11:51 pm MDT on 19 May 2026 ()
Where
2 km (2 mi) northwest of Challis, ID · earthquakes near Challis
Idaho today
every earthquake in Idaho in the last 24 hours
Magnitude
M 2.4 (ml)
Depth
5.4 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
Custer County, 28 km S
Nearest mapped fault
Lost River fault, 6 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 109 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 20 km (12 mi) from the epicentre. In Challis, 2 km away, the estimate is intensity III (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 2 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 89,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.9× the energy of this one
  4. This earthquake M 2.4 about 120 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 710 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 5.6 18 km ESE of Challis, Idaho · 20 km ESE of this epicentre
  2. 5.5 22 km E of Clayton, Idaho · 29 km SSE of this epicentre
  3. 5.4 23 km E of Clayton, Idaho · 34 km SSE of this epicentre
  4. 5.1 9 km SE of Challis, Idaho · 12 km SE of this epicentre
  5. 5.0 9 km E of Challis, Idaho · 11 km E 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 44.5217, -114.2511. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Custer County, ID 28 km (17 mi) S earthquakes near Custer County
Lemhi County, ID 54 km (33 mi) NNE earthquakes near Lemhi County
Valley County, ID 114 km (71 mi) WNW earthquakes near Valley County
Camas County, ID 121 km (75 mi) SSW earthquakes near Camas County
Butte County, ID 126 km (79 mi) SE earthquakes near Butte County
Beaverhead County, MT 127 km (79 mi) ENE earthquakes near Beaverhead County

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

Aftershocks so far

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

  1. 2.2 21 km W of Clayton, Idaho
  2. 1.7 25 km SSE of Challis, Idaho
  3. 2.0 8 km SSW of Challis, Idaho
  4. 2.3 7 km E of Challis, Idaho
  5. 2.6 4 km NW 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.