QuakeIndex

Fault · Washington

Rattlesnake Mountain fault

39 kmlong (24 mi), as mapped
not measuredhow fast it slips
< 15,000 yearssince it last broke the surface
26quakes of M2.5+ within 10 km since 2016

In plain English

Its most recent surface rupture is younger than 15,000 years.

This week vs. its last ten years

99/100

unusual

2 quakes of M1.5+ within 5 km of the trace in the last 7 days — busier than 99% of weeks since 2016. A normal week: 0–0.

Computed from the USGS catalogue · a description of the past, not a forecast · method

Olympia structureSeattle faultSouthern Whidbey Island faultTacoma faultCherry Creek fault
The Rattlesnake Mountain fault as mapped at the surface (glowing), with the other mapped faults nearby, 26 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), . Traces: USGS Quaternary Fault and Fold Database. Historic epicentres are estimates.

Every year since 2016

Earthquakes of M2.5+ with an epicentre within 10 km of the mapped trace. Near is not the same as on: some will have slipped on neighbouring faults.

Most recent near it

  1. M 3.0 2 km NNW of Ames Lake, Washington
    2026-01-22 · 0 km from the trace
  2. M 2.8 3 km NE of Fall City, Washington
    2025-07-31 · 3 km from the trace
  3. M 3.3 8 km NNE of Snoqualmie, Washington
    2025-02-27 · 8 km from the trace
  4. M 2.8 8 km ENE of Fall City, Washington
    2025-01-21 · 7 km from the trace
  5. M 3.5 9 km NE of Snoqualmie, Washington
    2025-01-20 · 9 km from the trace
  6. M 2.6 7 km NE of Fall City, Washington
    2024-10-04 · 7 km from the trace

Neighbouring faults

Fault trace, slip rate and age: USGS Quaternary Fault and Fold Database (public domain), simplified for the web. Earthquakes: USGS ComCat. QuakeIndex does not forecast earthquakes; a fault's history describes the past. For early warning use ShakeAlert.