Spirit Lake is a

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

Skamania County, Washington Skamania County ( ) is a county located in the U.S. state of Washington. As of the 2020 census, the population was 12,036. The county seat and largest incorporated city is Stevenson, although the Carson River Valley CDP is more populous. S ...

, United States, located north of Mount St. Helens. It was a popular tourist destination for many years until Mount St. Helens erupted in 1980. Previously there had been six camps on the shore of Spirit Lake: Boy Scout ( Camp Spirit Lake), the Girl Scout Camp at Spirit Lake, two YMCA camps ( Camp Loowit, and Portland YMCA camp), Harmony Fall Lodge, and another for the general public. There were also several lodges accessible to visitors, including Spirit Lake Lodge and Mt. St. Helens Lodge. The latter was owned and operated by Harry R. Truman, a noted victim of the volcano's 1980 eruption.

Human history

The body of water was named "Spirit" by settlers after histories from Native American people in the area spoke of haunting spirits at the lake. The spirits, telling a story of life and death, formed out of the mists into various shapes of trees and animals, foretelling impending doom but good fortune in the afterlife. Any person who saw the apparitions were dead within a week. A post office named Spirit Lake existed for a brief time, renamed to "Lange" in 1910 after the postmaster. Early mining around the lake began at the turn of the 20th century and necessitated the first road to the area in 1901, replacing a treacherous trail considered unfit for wagons.

Geologic history

Prior to 1980, Spirit Lake consisted of two arms that occupied what had been the valleys of the North Fork Toutle River and a tributary. About 4,000 years ago, these valleys were blocked by

lahar A lahar (, from ) is a violent type of mudflow or debris flow composed of a slurry of Pyroclastic rock, pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a valley, river valley. Lahars are o ...

s and

pyroclastic flow A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...

deposits from Mount St. Helens to form the pre-1980 Spirit Lake. The longest branch of Spirit Lake was about long. A stable outlet channel flowed from the lake to the North Fork Toutle River across a natural dam composed of volcanic material. The level of Spirit Lake remained basically stable, at an altitude of about .Hopson, CA (2008
''Geologic Map of Mount St. Helens, Washington Prior to the 1980 Eruption.''
Scale 1:62,500, Open-File Report no. 2002-468. U.S. Geological Survey, Reston, Virginia.Lipman, PW., and DR Mullineaux, eds. (1981
''The 1980 eruptions of Mount St. Helens, Washington.''
Professional Paper no. 1250. U.S. Geological Survey, Reston, Virginia. 844 pp.

1980 Mount St. Helens eruption

During the May 18, 1980, eruption of Mount St. Helens, Spirit Lake received the full impact of the lateral blast from the volcano. The blast and the debris avalanche associated with this eruption temporarily displaced much of the lake from its bed and forced lake waters as a

wave In physics, mathematics, engineering, and related fields, a wave is a propagating dynamic disturbance (change from List of types of equilibrium, equilibrium) of one or more quantities. ''Periodic waves'' oscillate repeatedly about an equilibrium ...

as much as above lake level on the mountain slopes along the north shoreline of the lake. The debris avalanche deposited about of pyrolized trees, other plant material, volcanic ash, and volcanic debris of various origins into Spirit Lake. The deposition of this volcanic material decreased the lake volume by approximately . Lahar and pyroclastic-flow deposits from the eruption blocked its natural pre-eruption outlet to the North Fork Toutle River valley at its outlet, raising the surface elevation of the lake by between and . The surface area of the lake was increased from to about and its maximum depth decreased from to . The eruption tore thousands of trees from the surrounding hillsides and swept them into Spirit Lake. These thousands of shattered trees formed a floating log raft on the lake surface that covered about 40% of the lake's surface after the eruption.Lee DB (1993
''Effects of the Eruptions of Mount St. Helens on Physical, Chemical, and Biological Characteristics of Surface Water, Ground Water, and Precipitation in the Western United States.''
Water-Supply Paper no. 2438. U.S. Geological Survey, Reston, Virginia. After the eruption, Spirit Lake contained highly toxic water with

volcanic gas Volcanic gases are gases given off by active (or, at times, by dormant) volcanoes. These include gases trapped in cavities (Vesicular texture, vesicles) in volcanic rocks, dissolved or dissociated gases in magma and lava, or gases emanating from ...

es seeping up from the lake bed. A month after the eruption, the bacteria-carrying water was devoid of

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

. Scientists predicted that the lake would not recover quickly, but the reemergence of phytoplankton starting in 1983 began to restore oxygen levels. Amphibians such as frogs and salamanders recolonized the lake, and fish (reintroduced by fishermen) thrived.Dale, VH, FJ Swanson, and CM Crisafulli, eds. (2005
''Ecological Responses to the 1980 Eruption of Mount St. Helens.''
Springer Science+Business Media, Inc., New York, New York, 342 pp. Larson, D (1993
''The Recovery of Spirit Lake.''American Scientist.
81(2):166-177.

Water levels

The water level of Spirit Lake is maintained at about by draining water through Spirit Lake Outlet Tunnel, a gravity-feed

tunnel A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ve ...

completed in 1985. The tunnel was cut through Harrys Ridge to South Coldwater Creek, which flows to Coldwater Lake and into the North Fork of the Toutle River. Had the lake level not been stabilized, the dam, which was composed of volcanic avalanche debris created by the 1980 eruption, would have been breached and caused catastrophic flooding within the Toutle River Valley.Swift, CH, and DL Kresch (1983
''Mudflow hazards along the Toutle and Cowlitz Rivers from a hypothetical failure of Spirit Lake blockage. ''
Water-Resources Investigations Report no. 82-4125. U.S. Geological Survey, Reston, Virginia.Kresch, DL (1992
''Development and routing of mudflow resulting from hypothetical failure of Spirit Lake debris dam, Washington.''
Water-Resources Investigations Report no. 91-4028. U.S. Geological Survey, Reston, Virginia. An attempt to upgrade and repair the 1985 tunnel began in 2021 but was halted due to concerns over damages to the pumice plain. The project restarted in 2024 and a temporary road, following the prior access path to the lake, will be rebuilt with future work to involve the installation of gates to the tunnel and

dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing d ...

to prevent the buildup of logs. During the efforts planned through 2027, several trails surrounding the area will no longer be accessible during weekdays.

Climate

Pre-eruption weather data from the Spirit Lake Ranger Station indicates the area either had the rare dry-summer variant of the

subarctic climate The subarctic climate (also called subpolar climate, or boreal climate) is a continental climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of ...

(

Köppen climate classification The Köppen climate classification divides Earth climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (te ...

: Dsc), or the rare cold-summer mediterranean climate (

: Csc), both of which are found only in small areas across the world. Recent climate data for the area is not available to confirm whether the post-eruption site still has either one of these rare climate types.

Gallery

File:St Helens before 1980 eruption.jpg, Spirit Lake prior to 1980 File:MSH80 blast area spirit lake with rainier 10-04-80 med.jpg, Spirit Lake filled with debris from the eruption. October 4, 1980 File:SpiritLake.jpg, Logs covering Spirit Lake, 2009 File:Spirit Lake (Washington).jpg, Spirit Lake File:SpiritLake2012Treemat01.jpg, Tree mats on Spirit Lake, 2012 File:SpiritLake2012Treemat02.JPG, Spirit Lake with tree mats and Mount St. Helens File:MSHtoutleareaedit.jpg, Shows the major changes in hydrology of Mount St. Helens after its 1980 eruption, including artificial modifications designed to mitigate sediment and water flow. File:View above Mount St. Helens National Volcanic Monument in Washington 2.jpg, View above Spirit Lake

References

External links

* Anonymous, (2006
''CVO Photo Archives: Hydrology and Hydrologic Monitoring Images.''Cascades Volcano Observatory
United States Geological Survey, Vancouver, Washington. * Glicken, HX, W Meyer, and MA Sabol, (1989
''Geology and ground-water hydrology of Spirit Lake blockage, Mount St. Helens, Washington, with implications for lake retention.''
Bulletin no. 1789. U.S. Geological Survey, Reston, Virginia. * Evarts, RC, and RP Ashley (1993a

scale 1:24,000, Geologic Quadrangle no. 1679, U.S. Geological Survey, Reston, Virginia. * Evarts, RC, and RP Ashley (1993b

scale 1:24,000, Geologic Quadrangle no. 1681, U.S. Geological Survey, Reston, Virginia. * Patton, V (2007
''Ecological Mysteries of Spirit Lake''
Documentary produced by Oregon Field Guide, Oregon Public Broadcasting. {{authority control Lakes of Washington (state) Lakes of Skamania County, Washington Mount St. Helens Gifford Pinchot National Forest