West Crater

Photo of this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 45.88°N
  • 122.08°W

  • 1329 m
    4359 ft

  • 321060
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for West Crater.

The Global Volcanism Program has no Weekly Reports available for West Crater.

The Global Volcanism Program has no Bulletin Reports available for West Crater.

Eruptive History


Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
5750 BCE (?) Unknown Confirmed 2 Radiocarbon (uncorrected) Bare Mountain
6110 BCE (?) Unknown Confirmed 2 Radiocarbon (uncorrected) West Crater, Hackamore Creek cone

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Photo Gallery


The valley floor in the foreground of this area of extensive logging clearcuts SE of Mount St. Helens, the peak seen in the distance, is covered by lava flows from West Crater and the Hackamore Creek scoria cone just NW of West Crater. Carbon fragments from a black tephra deposit produced by the Hackamore Creek scoria cone were dated at about 8000 years.

Photo by Lee Siebert, 1995 (Smithsonian Institution).
See title for photo information.
The forest-covered Bare Mountain explosion crater in the foreground is 400-m-wide and 275-m-deep. It formed about 7700 years ago during the youngest volcanic eruption in the West Crater volcanic field. West Crater itself is visible 4 km to the south at the extreme right side of the photo. The Bare Mountain phreatic crater was formed in older Tertiary volcanic rocks, and unlike other Holocene eruptions in the West Crater area, was not accompanied by lava flows.

Photo by Lee Siebert, 1995 (Smithsonian Institution).
See title for photo information.
Trout Creek Hill, a small Quaternary shield volcano in the West Crater volcanic field, is seen here from the NW, with Mount Hood across the Columbia River in Oregon in the background. Lava flows from Trout Creek Hill traveled 13 km to the SE, reaching the Columbia River.

Photo by Lee Siebert, 1995 (Smithsonian Institution).
See title for photo information.
The large partially forested lava flow in the foreground originated from West Crater, out of view to the right, about 8000 years ago. The blocky andesitic flow, seen here about 2 km from the vent, traveled about 4.5 km to the SE. In addition to this eastern flow, another lava flow traveled to the NW down the Hackamore Creek drainage. West Crater is a lava dome with a 200-m-wide summit crater that straddles a topographic divide in southern Gifford Pinchot National Forest.

Photo by Lee Siebert, 2002 (Smithsonian Institution).
See title for photo information.
West Crater is a little-known Quaternary volcanic field in the southern Cascades of Washington between Mount St. Helens and Mount Hood. West Crater itself, seen here from the NE, is an andesitic dome with two small lava flows, one of which forms the bare area at the right center. The 290-m-high dome was formed about 8060 years ago on the floor of a cirque carved into older Tertiary volcanic rocks. The West Crater volcanic field consists of a series of small shield volcanoes and cinder cones along a NW-SE zone.

Photo by Lee Siebert, 2002 (Smithsonian Institution).
See title for photo information.

Smithsonian Sample Collections Database


The following 2 samples associated with this volcano can be found in the Smithsonian's NMNH Department of Mineral Sciences collections. Catalog number links will open a window with more information.

Catalog Number Sample Description
NMNH 117652-38 Basalt
NMNH 117652-39 Basalt

Affiliated Sites