• Mount Rainier peeks through clouds, viewed across subalpine wildflowers and glacial moraine.

    Mount Rainier

    National Park Washington

There are park alerts in effect.
show Alerts »
  • Nisqually to Paradise Delays

    Road construction from the Nisqually Entrance to Longmire. Expect a 30-minute delay, Monday through Friday. More »

  • High Water & Inclement Weather Create Hazardous River Crossings

    Several Wonderland trail bridges on the White River and Carbon River have been washed out by high water. Be advised that some crossings will need to be forded, and in some cases may be impassable while inclement conditions continue. More »

Volcanoes

Mount Rainier viewed from the crater of Mount St. Helens.
Mount Rainier as seen from the crater rim of Mount St. Helens, overlooking Spirit Lake.
USGS Photo
 

Mount Rainier is an episodically active composite volcano, also called a stratovolcano. Volcanic activity began between one half and one million years ago and last erupted as recently as the 1890s. Over the past half million years, Mount Rainier has erupted again and again, alternating between quiet lava-producing eruptions and explosive debris-producing eruptions. The eruptions built up layer after layer of lava and loose rubble, eventually forming the tall cone that characterizes composite volcanoes. At one time, lava flows on opposite sides of the mountain probably projected more than 1,000 feet (305 meters) above the present summit at Columbia Crest which rises 14,410 feet (4392 meters) above sea level on the rim of the recent lava cone. The upper portion of the volcano's cone was likely removed by explosions and landslides. Mount Rainier's extensive glacier system then carved the volcano's cone into its current craggy form.

Mount Rainier also sits on a subduction zone where colliding continental and oceanic plates cause regular seismic and geothermal activity. A subduction zone is an area where one continental plate is being forced underneath another into the earth's mantel. Mount Rainier experiences about 20 small earthquakes a year, making it the second most seismically active volcano in the northern Cascade Range after Mount St. Helens. Learn more about Mount Rainier's seismicity.

 
Volcano evacuation route sign.

Volcano evacuation route sign.

Hazards of Mount Rainier
Mount Rainier, the highest (14,410 feet / 4392 m) volcano in the Cascade Range, towers over a population of more than 3.3 million in the Seattle Tacoma metropolitan area, and its drainage system via the Columbia River potentially impacts another 500,000 residents of southwestern Washington and northwestern Oregon. Mount Rainier is the most hazardous volcano in the Cascades not only in terms of its potential for eruption, but also the risk of producing major debris flows even without eruption.

The potential hazards posed by Mount Rainier led to its inclusion as one of the sixteen volcanoes worldwide to be designated Decade Volcanoes. The Decade Volcano initiative is part of a United Nations program aimed at better utilizing science and emergency management to reduce the severity of natural disasters. Mount Rainier was chosen to be studied because it is representative of one or more volcanic hazards: it is geologically active as evidenced by surface manifestation of heat (geothermal activity), it has had recent volcanic events (last eruption was about 150 years ago), and it is likely to erupt again, based on past history; its location poses significant hazards to a heavily populated area; it is a well known volcano (a number of research publications have been written on it); it is politically and physically accessible for study; and its volcanic geology is well exposed.

In 1992 National Park Service staff participated with other agencies and individuals to develop a science plan through the National Academy of Sciences, for organizing the needed research to evaluate the hazards and risks associated with Mount Rainier and for developing communication efforts of the risks for appropriate planning activities. The science plan was published in Mount Rainier Active Cascade Volcano and is available in the park library. Several studies related to geologic hazards are being conducted by the USGS, other federal and state agencies, and academic institutions.

 

Additional Mount Rainier Volcano Information:
Mount Rainier Volcano - USGS description, history, and points of interest.
History and Hazards of Mount Rainier - T. Sisson, 1995, USGS
Volcano Hazards from Mount Rainier, revised 1998 - Hoblitt, et. al., 1998, USGS
Mount Rainier Eruptive History - USGS
Volcanoes of Lewis and Clark: Mount Rainier - USGS

Did You Know?

Floyd Schmoe, Mount Rainier's first full-time Park Naturalist.

Floyd Schmoe was Mount Rainier's first full-time Park Naturalist. In 1923, he launched the park's "Nature Notes", a series of writings on various park-related topics. There are hundreds of editions of the notes in the park's collection, all of which are accessible through the Mount Rainier History & Culture webpage: More...