M2.3 earthquake 7 km SW of Colusa, California

A magnitude 2.3 earthquake struck 7 km SW of Colusa, California on Fri, Jul 5, 1985, 4:10 AM PDT (11:10 UTC), 15 km (9 mi) below the surface.

A larger quake followed: M3.3 7 km W of Cobb, California. This one was a foreshock.

Map

Where this earthquake was located, with the others nearby. Select one for its page.

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Distance and direction from each place to the epicenter, with its forecast.

Within 100 km, magnitude 1.5 and up: 177 in the 60 days after this one and 0 in the 30 days before it.

The first 60 of 177.

From the USGS Earthquake Hazards Program and its partner networks, event nc51182. Read Tue, Sep 22, 2026, 5:27 PM UTC.