Toutle River

Toutle River
River
Mouth of the Toutle River in flood near Castle Rock, Washington. Photo taken prior to the 1980 eruption of Mt. St. Helens
Country	United States
State	Washington
Coordinates	46°18′39″N 122°55′6″W
Source	Mt. St. Helens
- coordinates	46.21195°N 122.193895°W / 46.21195; -122.193895
Mouth	Cowlitz River
- coordinates	46.310389°N 122.916455°W / 46.310389; -122.916455
Length	17.2 mi (28 km)
Basin	511 sq mi (1,323 km2)
Discharge	for river mile 6.5 (rkm 10.5)
- average	2,071 cu ft/s (59 m3/s)
- max	61,800 cu ft/s (1,750 m3/s)
- min	243 cu ft/s (7 m3/s)

The Toutle River is a river in southwestern Washington State, in the Pacific Northwest region of the United States. It rises in two forks on the flanks of Mount St. Helens and joins the Cowlitz River near Castle Rock.

Eruption of Mount St. Helens

The May 18, 1980 eruption of Mount St. Helens and subsequent lahars poured vast amounts of sediment into the Toutle, which was formerly navigable. The US Army Corps of Engineers dredged 85 million m³ (110 million yd³) of sediment from the river and built the US$65 million Sediment Retention Structure on the North Fork of the Toutle to keep it clear in the future. Part of the same engineering works is a tunnel to drain Spirit Lake whose natural outlet was blocked by the eruption.

North Fork Toutle River valley filled with landslide debris and hummocks	Dredging the Toutle River of volcanic ash
The sediment retention structure on the North Fork of the Toutle River

See also

• List of rivers of Washington
• List of tributaries of the Columbia River

External links

• U.S. Geological Survey Geographic Names Information System: Toutle River
• Taming the Toutle River Seattle Times, October 25, 2004
• Sediment Retention Structure – U.S. Army Corps of Engineers