M3.5 earthquake on Maacama fault rattles Mendocino coast range

An M3.5 earthquake struck 15 km north of Brooktrails, California on March 25, 2026 at 9:20 AM PDT (16:20:48 UTC). USGS placed the epicenter in Mendocino County at a depth of 9.2 kilometers, about 6.9 km from the mapped trace of the Maacama fault zone (northern section).

The event drew 42 "Did You Feel It?" reports submitted to USGS, with a community-reported intensity (CDI) of 3.4. ShakeMap modeled a maximum instrumental intensity (MMI) of 3.3. Both values are consistent with weak-to-light shaking felt indoors across the rural Coast Range.

USGS reviewed the event and assigned a moment magnitude (Mw) of 3.5. USGS assigned a significance score of 201 on its internal 0–1000 scale. USGS PAGER did not produce a population-exposure estimate for this event.

USGS catalog data shows 4 other M3.5+ earthquakes within 20 km of this epicenter in the past 10 years, suggesting events of this size occur about once every 2.5 years at this location.

Mendocino County has a population of approximately 89,000.

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Event data

• Magnitude: M3.5 (Mw)
• Depth: 9.20 km
• Time: 2026-03-25 09:20 AM PDT (16:20:48 UTC)
• Coordinates: 39.5755°N, -123.3603°W
• County: Mendocino
• Nearest mapped fault: Maacama fault zone (northern section), 6.9 km
• USGS event page: https://earthquake.usgs.gov/earthquakes/eventpage/nc75332857