M1.7 earthquake 18km NW of Bridgeport, CA

A magnitude 1.7 earthquake struck 18km NW of Bridgeport, CA on Mon, Sep 6, 2021, 8:41 PM PDT (03:41 UTC), 3 km (2 mi) below the surface.

A larger quake followed: M4.0 30km SSW of Smith Valley, NV. This one was a foreshock.

Map

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

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
1.71	Md, duration	Northern California Seismic System	Preferred · Final · ±0.205 · 18 stations
1.3	ML, local (Richter)	Nevada Seismological Laboratory	Preliminary · ±0.19 · 11 stations

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: at least 201 in the 60 days after this one and at least 200 in the 30 days before it.

The first 60 of at least 201.

From the USGS Earthquake Hazards Program and its partner networks, event nc73621461 (also filed as nn00821457). Read Mon, Oct 5, 2026, 4:15 AM UTC.