Jefferson, United States

Stratovolcano · 3,199 m (10,495 ft) · US-Oregon

Jefferson is a stratovolcano in the United States, 3,199 m (10,495 ft) high. Its last known eruption: aD 1 to 1499. NOAA records no significant eruption here.

Jefferson on the map

Jefferson 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 20:28 UTC. USGS threat ranking: Low Threat.

Normal / Green Cascades Volcano Observatory rates Jefferson at alert level Normal, aviation color code Green.

The observatory’s page

The volcano

Type: Stratovolcano
Elevation: 3,199 m (10,495 ft)
Country: United States
Region: US-Oregon
Summit: 44.674° N, 121.800° W
Last known eruption: AD 1 to 1499
Holocene activity known from: Varve Count
Smithsonian volcano number: 322020

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 Jefferson 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. 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.