Volcanoes of the United States

Three Sisters, United States

Complex volcano · 3,159 m (10,364 ft) · US-Oregon

Three Sisters is a complex volcano in the United States, 3,159 m (10,364 ft) high. Its last known eruption: aD 1 to 1499. NOAA records no significant eruption here.

Three Sisters on the map

Three Sisters and the volcanoes within 300 km, colored by when each last erupted.

  • Since 1964
  • 1900 to 1963
  • 1800s
  • AD 1 to 1799
  • Before AD 1, or undated

Open the live map with volcanic ash advisories

Now

From the USGS Volcano Hazards Program, read 22:05 UTC. USGS threat ranking: Very High Threat.

Normal / Green Cascades Volcano Observatory rates Three Sisters at alert level Normal, aviation color code Green, since 2022-01-31 20:45 UTC.

CVO Three Sisters GREEN/NORMAL - An increase in the rate of ground uplift has been detected by satellite. It is like past periods of uplift. Small earthquakes also detected in the same area. No sign of imminent eruption.

The latest noticeThe observatory’s page

The volcano

Type
Complex volcano
Elevation
3,159 m (10,364 ft)
Region
US-Oregon
Summit
44.133° N, 121.767° W
Last known eruption
AD 1 to 1499
Holocene activity known from
Radiocarbon
Smithsonian volcano number
322070

Significant eruptions

NOAA records eruptions that killed, did damage, were very large, or set off a tsunami or earthquake.

None on record.

Around it

The volcanoes within 300 km.

Earthquakes near Three SistersVolcanic ash advisories on the live map

Sources

Volcanoes and significant eruptions from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. Alert levels, color codes and notices from the USGS Volcano Hazards Program and its observatories, public domain. Volcano numbers are the Smithsonian Institution’s Global Volcanism Program’s.