M3.3 earthquake 4 km SW of Challis, Idaho
A magnitude 3.3 earthquake struck 4 km SW of Challis, Idaho on Fri, Apr 19, 1985, 11:20 PM MST (06:20 UTC), 10 km (6 mi) below the surface.
A larger quake followed: M3.4 16 km E of Clayton, Idaho. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 3.3 (ml), minor
- Local time
- UTC
- 1985-04-20 06:20:34 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 44.474° N, 114.273° W
- Region
- Idaho
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Did you feel it?
No one has reported feeling this quake to the USGS.
How well it is located
Reviewed by a seismologist.
- Depth from
- OPERATOR_ASSIGNED
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 7 in the 60 days after this one and 8 in the 30 days before it.
After
- 3.15 km SW of Challis, Idaho · 15121 days ago · 5 km deep · 1 km away
- 3.023 km S of Clayton, Idaho · 15119 days ago · 5 km deep · 48 km away
- 3.113 km NE of Challis, Idaho · 15117 days ago · 5 km deep · 19 km away
- 3.225 km NW of Mackay, Idaho · 15115 days ago · 5 km deep · 57 km away
- 3.012 km NNW of Clayton, Idaho · 15115 days ago · 5 km deep · 20 km away
- 3.416 km E of Clayton, Idaho · 15089 days ago · 10 km deep · 25 km away
- 3.01 km ESE of Challis, Idaho · 15085 days ago · 5 km deep · 5 km away
Before
- 3.3Idaho-Montana border region · 15141 days ago · 10 km deep · 70 km away
- 3.030 km WNW of Mackay, Idaho · 15143 days ago · 5 km deep · 59 km away
- 3.214 km ENE of Clayton, Idaho · 15148 days ago · 10 km deep · 19 km away
- 3.130 km NW of Mackay, Idaho · 15158 days ago · 5 km deep · 51 km away
- 3.126 km NW of Clayton, Idaho · 15164 days ago · 10 km deep · 28 km away
- 3.441 km ESE of Challis, Idaho · 15165 days ago · 5 km deep · 42 km away
- 3.539 km ESE of Challis, Idaho · 15165 days ago · 5 km deep · 41 km away
- 3.18 km SSE of Clayton, Idaho · 15166 days ago · 10 km deep · 33 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0002dyj. Read Wed, Sep 30, 2026, 4:06 AM UTC.