South Sister, United States

Complex volcano · 3,157 m (10,358 ft) · US-Oregon

South Sister is a complex volcano in the United States, 3,157 m (10,358 ft) high. Its last known eruption: bC (Holocene). NOAA records no significant eruption here.

South Sister on the map

South Sister 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

No USGS alert level is set for this volcano, or the USGS did not answer just now.

The volcano

Type: Complex volcano
Elevation: 3,157 m (10,358 ft)
Country: United States
Region: US-Oregon
Summit: 44.100° N, 121.770° W
Last known eruption: BC (Holocene)
Holocene activity known from: Radiocarbon

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 South Sister Volcanic 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. Volcano numbers are the Smithsonian Institution’s Global Volcanism Program’s.