Mount Rainier

Mount Rainier

Mount Rainier with its main summit, Columbia Crest (14410 feet) at the center. Massive Emmons Glacier covers most of the visible flank of the mountain. Left of the glacier is sharp pointed Little Tahoma (11138 feet) with Frying Pan Glacier on its flank.
Elevation: 14,410 ft (4,392 m)
Location: Washington State, USA
Range: Cascades
Prominence: 13,211 ft (4026 m)
Coordinates: 46°51′11.9″N, 121°45′35.6″W
Topo map: USGS Mount Rainier West
Type: Composite volcano
Age of rock: < 500000 yr
Last eruption: 1854
First ascent: 1870 by Hazard Stevens and P.B. Van Trump
Easiest route: rock/ice climb via Disappointment Cleaver

Mount Rainier is a stratovolcano located 54 miles (87 km) southeast of Seattle, Washington, in the United States. It is the highest peak in the Cascade Range, with a topographical summit of 14,411 feet (4,392 m); there is no greater elevation until the meeting of the borders of Yukon, Alaska, and British Columbia beyond the Alsek River to the north. The mountain and the surrounding area comprise Mount Rainier National Park. The mountain is mostly covered by snow and glaciers, but heat from the volcano keeps areas of the crater rim on its summit cone mostly free of snow and ice. The geothermal heat has also caused the formation of ice caves in the twin summit craters.

Mount Rainier was originally known as Tahoma or Tacoma, from the Puyallup word tacobet ("mother of waters"). It has a topographic prominence on the southern horizon of 13,211 feet (4026 m), greater than that of K2. Because of its scenic dominance, Seattle/Tacoma-area residents often refer to it simply as "the Mountain." [1]

Mountain climbing on Mount Rainier is difficult. It includes climbing on the largest glaciers in the U.S. south of Alaska and most climbers require two to three days to reach the summit, with weather and conditioning being the most common reasons for failure. Climbing teams require experience in glacier travel, self-rescue, and wilderness travel. About 20,000 people attempt the climb each year, about 90% via routes from Camp Muir on the southwest flank. Most of the rest ascend Emmons Glacier via Camp Schurman on the northeast. About half of the attempts are successful. About ten deaths each year are due to rock fall, falls, and hypothermia associated with severe weather.

Hiking, photography, and camping are very popular in the park. There are several hiking trails, including the Wonderland Trail, a 93-mile circumnavigation of the peak. Mount Rainier is also popular for winter sports, including snowshoeing and cross-country skiing.

The Carbon, Puyallup, Nisqually, and Cowlitz Rivers begin at eponymous glaciers of Mount Rainier. The sources of the White River are Winthrop, Emmons and Fryingpan Glaciers. The White and Carbon join the Puyallup River which discharges into Commencement Bay at Tacoma, the Nisqually empties into Puget Sound east of Lacey and the Cowlitz joins the Columbia River between Kelso and Longview.

Geological history

Mount Rainier's earliest lavas are over 840,000 years old and are part of the Lily Formation.(2.9 million to 840,000 years ago) The early lavas formed a "proto-Rainier" or an ancestral cone prior to the present-day cone. The present cone is over 500,000 years old (Sisson 1995). The volcano is highly eroded, with glaciers on its slopes, and appears to be made mostly of andesite. Rainier likely once stood even higher than today before a major debris avalanche and the resulting Osceola Mudflow 5000 years ago.

Hazard map
Hazard map

In the past, Rainier has had large debris avalanches, and has also produced enormous lahars(volcanic mudflows) due to the large amount of glacial ice present. Its lahars have reached all the way to the Puget Sound. Around 5000 years ago, a large chunk of the volcano slid away and that debris avalanche helped to produce the massive Osceola Mudflow, which went all the way to the site of present-day Tacoma and south Seattle. About 530 to 550 years ago, the Electron Mudflow occurred, although this was not as large-scale as the Osceola Mudflow.

After the major collapse 5000 years ago, subsequent eruptions of lava and tephra built up the modern summit cone until about as recently as 1000 years ago. As many as 11 Holocene tephra layers have been found.

The most recent recorded volcanic eruption was between 1820 and 1854, but many eyewitnesses reported eruptive activity in the late 19th century (Harris 1988). As of 2002, there is no imminent risk of eruption, but geologists expect that the volcano will erupt again.

Lahars from Rainier pose the most risk to life and property, as many communities lie atop older lahar deposits. Not only is there much ice atop the volcano, the volcano is also slowly being weakened by hydrothermal activity. According to Geoff Clayton, a geologist with RH2, a repeat of the Osceola mudflow would destroy Enumclaw, Kent, Auburn, and most or all of Renton. Such a mudflow may also reach down the Duwamish estuary and destroy parts of downtown Seattle, and (speculatively) may cause tsunamis in Puget Sound and Lake Washington.

Rainier is also capable of producing pyroclastic flows as well as lava.

Massive Tahoma Glacier descends southwest from the summit ice cap flanked by Puyallup and South Tahoma Glaciers
Massive Tahoma Glacier descends southwest from the summit ice cap flanked by Puyallup and South Tahoma Glaciers

Human history

Mount Rainier was first discovered by the Native Americans. At the time of European contact, the river valleys and other areas near the mountain were inhabited by many Pacific Northwest tribes who hunted and gathered berries in the forests and mountain meadows. These included the Nisqually, Cowlitz, Yakama, Puyallup, and Muckleshoot.

Captain George Vancouver reached Puget Sound in 1792 and became the first European to see the mountain. He named it in honor of his friend, Rear Admiral Peter Rainier.

In 1833, Dr. William Tolmie explored the area looking for medicinal plants. He was followed by other explorers seeking challenge. Hazard Stevens and P.B. Van Trump received a hero's welcome in the streets of Olympia after their successful summit climb in 1870. John Muir climbed Mount Rainier in 1888, and although he enjoyed the view, he conceded that it was best appreciated from below. Muir was one of many who advocated protecting the mountain. In 1893, the area was set aside as part of the Pacific Forest Reserve in order to protect its physical/economic resources: timber and watersheds.

Citing the need to also protect scenery and provide for public enjoyment, railroads and local businesses urged the creation of a national park in hopes of increased tourism. On March 2, 1899, President William McKinley established Mount Rainier National Park as America's fifth national park. Congress dedicated the new park "for the benefit and enjoyment of the people; and...for the preservation from injury or spoliation of all timber, mineral deposits, natural curiosities, or wonders within said park, and their retention in their natural condition."

In 1998, the United States Geological Survey began putting together the Mount Rainier Volcano Lahar Warning System to assist in the evacuation of the Puyallup River valley in the event of a catastrophic debris flow. It is now run by the Pierce County Department of Emergency Management. Tacoma, at the mouth of the Puyallup, is only 37 miles west of Rainier, and moderately sized towns such as Puyallup and Orting are only 27 and 20 miles away, respectively.