Carte topographique Spirit Lake

Nom : Carte topographique Spirit Lake, altitude, relief.

Lieu : Spirit Lake, Skamania County, Washington, United States (46.24663 -122.16614 46.29837 -122.11151)

Altitude moyenne : 1 144 m

Altitude minimum : 905 m

Altitude maximum : 1 609 m

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 lahars and pyroclastic flow deposits from Mount St. Helens to form the pre-1980 Spirit Lake. The longest branch of Spirit Lake was about 2.1 miles (3.4 km) 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 3,198 ft (970 m).

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